Temporal variability of in situ methane concentrations in gas hydrate-bearing

sediments near Bullseye Vent, Northern Cascadia Margin

Laura Lapham, University of Maryland Center for Environmental Science, Solomons, MD

20688, lapham@umces.edu

Rachel Wilson, Florida State University, Tallahassee, FL 32303, rachelyounge@gmail.com

Michael Riedel, Geological Survey of Canada, Sidney, V8L4B2, British Columbia, Canada,

Michael.Riedel@nrcan-rncan.gc.ca

Charles K. Paull, Monterey Bay Aquarium Research Institute, Moss Landing, CA,

paull@mbari.org

M. Elizabeth Holmes, Florida State University, Tallahassee, FL 32303, bhuettel@fsu.edu

Index terms: 0414 Biogeochemical cycles, 0454 Isotopic composition and chemistry, 0460

Marine systems, 4277 Time-series experiments, 7209 Earthquake dynamics

Regular Article Geochemistry, Geophysics, GeosystemsDOI 10.1002/ggge.20167

This article has been accepted for publication and undergone full peer review but has not beenthrough the copyediting, typesetting, pagination and proofreading process which may lead todifferences between this version and the Version of Record. Please cite this article asdoi: 10.1002/ggge.20167

© 2013 American Geophysical UnionReceived: Oct 10, 2012; Revised: Apr 25, 2013; Accepted: May 02, 2013

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Abstract

To assess the temporal variability in the methane fluxes from marine sediments that

overly gas hydrate bearing sediments and the factors that might control its rate, in situ methane

concentrations were measured near Bullseye Vent on the Northern Cascadia continental margin.

A long-term sampling device collected overlying water and pore-fluid samples from 25 cm

above seafloor, at the sediment-water interface, and 7 cmbsf (cm below seafloor) over a 9-month

period (August 2009-May 2010). These samples provide a record at ~4 day resolution of in situ

methane, ethane, propane, sulfate, and chloride concentrations, as well as stable carbon isotope

ratios of methane (δ13

C-CH4) and dissolved inorganic carbon (δ13

C -DIC). We show that pore-

fluids near the sediment-water interface are saturated or super-saturated with respect to methane

(~80 mM) and the methane flux from the seabed is variable over time. We hypothesized that

regional seismic activity controlled this variable CH4 flux in the Northern Cascadia continental

margin setting. However, we found no direct correlation between earthquakes and CH4 flux.

We also posited alternative controls on CH4 flux variability, such as storms, regional

oceanography and microbial activity. Again, no direct correlation was seen. This study takes

first steps towards exploring which physical factors play a role in methane flux from hydrate-

bearing sediments.

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1. Introduction

Deep-sea sediments contain an enormous amount of methane as gas hydrate, ~500-2,500

Gt [Milkov, 2004], which are crystalline solids of methane gas contained within a water lattice

[e.g. Kvenvolden, 1995]. Since methane (CH4) is a powerful greenhouse gas, exhibiting >20

times more heat absorbing potential than carbon dioxide over 100 years [Forster et al., 2007],

understanding the factors that control its formation and release from such reservoirs is important.

Gas hydrate occurrences include occasional outcrops on the seafloor [e.g., MacDonald et al.,

1994] or in shallow marine sediments [e.g. Torres et al., 2002] and thus could be affected by

changes in pressure or temperature of overlying water. Here, we seek to better understand the

impact of physical events on CH4 fluxes from the seafloor and how these fluxes might impact the

sedimentary microbial processes involved in methane cycling.

Microbial processes mediate the flux of CH4 out of marine sediments [Reeburgh, 2007].

Methane is formed either by thermogenic alteration of buried organic matter or microbial

methanogesis in the sediment column. Due to low concentrations of methane in the water

column, it is constantly diffusing upwards toward the seafloor. As it diffuses up, it comes into

contact with downwardly diffusing sulfate, where it is subject to anaerobic oxidation via

bacterial sulfate reduction [Hoehler et al., 1994; Borowski et al., 1996; Boetius et al., 2000; Joye

et al., 2004]. Although ~90% of the CH4 is believed to be consumed before it leaves the

sediments [Reeburgh, 1996], some of this methane can bypass this microbial filter and reach the

overlying waters.

CH4 fluxes may also be controlled by physical processes such as tides and fluid flow

rates. For example, in shallow water, sedimentary CH4 fluxes can vary with the tides [Chanton

et al., 1989]. In deep water (>600m), where hydrates exist, tides can also control transient rates

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of fluid flow into and out of deep water chemosynthetic communities [Tryon et al., 1999; Tryon

and Brown, 2001; Torres et al., 2002; Solomon et al., 2008].

Beyond tides, microbial processes, and fluid flow, several studies have made an indirect

link between CH4 release and earthquakes. For example, in the Okhotsk Sea, gas flares found in

a tectonically active area of seabed were hypothesized to cause an increase in bottom water CH4

concentrations after the Neftegorsk earthquake in 1998 [Obzhirov et al., 2004]. A similar dataset

came from the Cariaco Basin where higher CH4 concentrations in the water column were

assumed to be a result of a 1967 earthquake [Kessler et al., 2005]. Mau et al. [2007] measured

an increase in bottom water CH4 concentrations offshore Chile after the 2002 earthquake. And

finally, a magnitude 5.8 earthquake in the Gulf of Mexico was hypothesized to have caused an

increase in CH4 from the sediment to the water column at a gas hydrate site [Lapham et al.,

2008].

In light of these studies, we hypothesize that earthquakes have a significant influence on

CH4 flux from sediments to the water column in the Northern Cascadia Margin.

Geological setting and site description

The Northern Cascadia continental margin contains the Juan de Fuca plate that is

subducting under the North American plate in the eastern Pacific Ocean, offshore Vancouver

Island, Canada. As subduction occurs, the folding and faulting sediments allow organic matter

to become buried and undergo microbial degradation. Eventually, CH4 is produced from these

primarily biogenic origins [Pohlman et al., 2005; Riedel et al., 2006; Pohlman et al., 2009b].

Over a large area of this margin, the pressure, temperature, and CH4 saturation conditions are

appropriate for gas hydrate formation [Spence et al., 2000]. Seafloor gas venting is also known

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to occur at several sites, including Bullseye Vent [Riedel et al., 2006]. Bullseye Vent has been

studied extensively in the previous 10 years including Integrated Ocean Drilling Program

Expedition 311 and thus the geological setting is extensively documented [Riedel et al., 2006;

Riedel et al., 2009]. Bullseye Vent is also near the ODP 889 node of the North-East Pacific

Time-series Underwater Networked Experiments (NEPTUNE) Canada cabled observatory

[Figure 1; Barnes and Tunnicliffe, 2008].

The focus of this study is a seafloor gas venting area (latitude 126.841529°, longitude

48.675127°) that lies ~1 km to the northeast of Bullseye Vent, called Bubbly Gulch (Figures 1b).

Vents occur in 1,265 m water depth within a presumed slump scar on the flank of the plateau on

which Bullseye Vent occurs [Riedel et al., 2006]. The existence of these vents was discovered

by water column acoustic anomalies in echo-sounder data [Vidalie, 2007]. In 2009, a detailed

bathymetric survey was conducted of the Bullseye Vent area by Monterey Bay Aquarium

Research Institute using an autonomous underwater vehicle (AUV) which was followed with

ROV dives that further explored Bubbly Gulch.

ROV observations show that the flank of Bubbly Gulch contains a series of small

topographic mounds that are ~10 m across and rise up to 1 m above the surrounding seabed

[Paull et al., 2009]. The surface of these mounds is marked with cracks that are several meters

in length (Figure 2). In 2009 the cracks were mostly open and gray mud was visible on the crack

walls and the side walls were fringed with white bacterial mats. However, the sediment, more

than ~20 cm away from the cracks, was indistinguishable from the brown silty mud

characteristic of the region. Neither clams nor authigenic carbonates were seen, but gas bubbles

were seen emanating from some of these cracks. Below the sediment surface, a hard layer exists

at ~50 cm depth and free gas is trapped underneath [Paull et al., 2009]. Similar seafloor cracks

6

elsewhere have been attributed to expansion associated with the formation of gas hydrate near

the seafloor [e.g. Hovland and Svensen, 2006; Paull et al., 2008].

During the 2009 ROV diving expedition to Bubbly Gulch, we deployed a long-term in

situ pore-water sampler (described below) within one of the seafloor cracks. The purpose of

deployment was to evaluate whether there are changes in the CH4 flux over time and if so, to

determine the factors influencing these changes. Here we report on the temporal evolution of in

situ CH4 concentrations associated with this time-series deployment. Along with concentrations,

stable isotopic ratios of both the CH4 and dissolved inorganic carbon (DIC) were measured.

Influence of microbial activity on the CH4 concentrations was also addressed by measuring

sulfate concentrations.

2. Methods

2.1. In situ CH4 concentrations

To obtain an “in situ” concentration, either sophisticated tools must be used to measure

these concentrations on the seafloor [e.g. Short et al., 2001; Camilli and Duryea, 2009; Zhang et

al., 2011; Wankel et al., 2013], or a sample must be collected from the seafloor and maintained at

in situ pressures when retrieved [e.g. Dickens et al., 1997; Lapham et al., 2008]. Otherwise, if

concentrations are above saturation at 1 atm, CH4 will come out of solution during ascent in the

water column [Wallace et al., 2000; Paull and Ussler, 2001]. For this study, we chose to collect

samples and maintain in situ pressures so that (1) complimentary analyses could be carried out

on the same sample and (2) pore-water samples, and not just bottom water, could be collected.

2.1.1. Description of Mini-Pore Fluid Array (mPFA). In situ CH4 concentrations were

measured on water samples collected with a mini-Pore Fluid Array (mPFA). The mPFA is a

7

modified version of an existing sample collection tool that collects and maintains samples at in

situ pressure [Lapham et al., 2008].

The mPFA is essentially a PVC box (45x60x60 cm) that contains three OsmoSamplers, a

high-pressure valve submerged in oil to reduce corrosion, and three 300 m long coils of 0.16 cm

outer diameter copper tubing (Figure 3). Each OsmoSampler has eight 2ML1 semi-permeable

membranes (Durect Co.) that separate a saturated salt solution from deionized water, creating an

osmotic potential, which creates the pump [Jannasch et al., 2004]. OsmoSamplers have been

successfully used in several gas hydrate related seafloor hydrocarbon seep settings [Tryon et al.,

1999; Tryon et al., 2002; Solomon et al., 2004; Tryon and Brown, 2004; Lapham et al., 2008].

Sampler pumping rates were calibrated in the laboratory prior to deployment and found to be

~0.5 mL/day at 4°C. The copper material was used so CH4 could not diffuse out during

deployment. The copper coils were filled with degassed, high purity fresh water (17 MΩ) before

deployment. Using 0.16 cm diameter tubing, the samplers were plumbed through the high-

pressure valve, to the coil and then to ports along a meter long, PVC, T-handled stick (Figure

3b). The sample ports collected samples from the overlying water (OLW), at the sediment-water

interface (SWI) and at 7 cmbsf (Figure 3b).

The mPFA was deployed 7 August 2009, using the ROV Doc Ricketts (dive 63) on the

R/V Western Flyer at Bubbly Gulch (Figure 3a). The high-pressure, multi-port, 2-position valve

was left in a position to allow sample flow to go from the ports, through the valve, to the coil,

and back through the valve. On 14 May 2010, the mPFA was retrieved by the ROV ROPOS

(dive 1328) on the R/V John P. Tully in conjunction with NEPTUNE Canada activities. The

ROV closed the valve on the seafloor so that the copper coils were isolated and not allowed to

degas upon retrieval of the mPFA package ensuring in situ pressures within the coils and in situ

8

CH4 concentrations were maintained. Upon visual inspection of the site, we found the seafloor

cracks were still open and there was an active bubble stream, but still no clams were observed.

One year later, however, in 2011, Bubbly Gulch was revisited again and we observed that the

cracks had been filled in with fresh sediment and live clams were visible, but no gas bubbles

emanated (Figure 2b).

Upon retrieval of the mPFA to the dock, the copper tubes were crimped using a crimping

tool that was pressure tested to hold up to 13.8 MPa pressure within the crimped copper tubing.

The coils were then stored at 4ºC until they were sub-sampled in the laboratory.

2.2. Subsampling copper coils

Once in the laboratory, the coils were cut into 4 m long sections. Based on the ~0.5

mL/day pumping rate determined in the lab and the size of the tubing (0.16-cm OD x 0.4-cm ID),

each 4 m section represents 4 days and gives about 2 mL sample volume. The water within each

of the 4 m long sections was then expelled into an evacuated 10 mL glass vial with blue butyl

rubber septa using a benchtop tube roller and a gas tight adapter to go from the tubing to a luer-

lock needle. As each section was rolled, the pressure would build up inside the tubing until it

exceeded what the end seal could handle and the water sample broke through the end seal into

the evacuated vial. Samples were not exposed to air. A ~10 µL sub-sample was then taken from

the vial to measure salinity with a handheld refractometer. Towards the end of the 300-m coil,

the salinities changed from seawater values (e.g., 35 psu) to fresh water (0 psu), which indicated

the end of the time-series. Sample vials were frozen upside down until future analysis.

2.3. Analytical techniques

A 100 µL sub-sample of the fluid in the vial was diluted 1:125 with milli-Q water and

measured for sulfate and chloride concentrations on a Dionex ion chromatograph (ICS-1000).

9

The remaining fluid in the vial was acidified with 100 µL of 40% nitric acid to measure

headspace for dissolved inorganic carbon (DIC) and CH4 concentrations and stable carbon

isotopes, along with ethane and propane concentrations.

CH4, ethane and propane concentrations were measured on a Shimadzu gas

chromatograph 2010 with a 50 m POROPLOT capillary column set at 30ºC with a 1-mL sample

loop. A temperature ramping program was used to elute ethane and propane (10 min at 30ºC,

ramp at 60ºC per minute to 150ºC and hold for 15 minutes). To each sample, helium gas was

added to the headspace to bring the evacuated vials to 1-atm pressure plus ~10-mL additional

helium to over-pressurize the vial for GC injection. The headspace was then equilibrated with

the ~2-mL water sample expelled from the copper sections and 5-mL of this headspace injected

to fill the 1-mL sample loop. By comparing the integrated areas with CH4, ethane, and propane

standards, headspace concentrations could then be calculated. In situ concentrations reported in

mM are corrected for the helium dilution and Bunsen solubility.

Stable carbon isotopes of CH4 and DIC were measured by directly injecting

microvolumes of headspace aliquots into a continuous flow Hewlett-Packard 5890 GC equipped

with a 6 m Poroplot Q column at 35C and a Thermo Delta V (Bremen, Germany) isotope ratio

mass spectrometer. Isotope ratios were reported using the standard “del” notation, δ13

C (‰) =

(R(sample)/R(PDB standard) – 1)*1000, where R is the ratio of the heavy to light isotope (13

C:12

C). CH4

headspace aliquots were obtained from vials previously measured for concentrations. Samples

were run in duplicate and analytical error was <0.6‰.

2.4. Bottom water temperature

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Bottom water temperature at Bubble Gulch was obtained from an Antares©

recording thermistor

affixed to the mPFA box. Measurements were made every 15 minutes for the deployment

period.

2.5. Statistics

Nonparametric Spearman Rank correlations were used to calculate correlations between

methane concentrations and earthquake magnitude and distance. Correlations were done using

the statistical package in OriginPro 9.0.

3. Results

A 9-month long time-series of CH4 concentrations was measured from overlying water

(OLW), at the sediment water interface (SWI), and at 7 cmbsf at a gas seep at Bubbly Gulch.

The probe stick was on the edge of the seafloor cracks which were filled with sediment (Figure

2b). Upon retrieval, the samplers were visually inspected, and there were no obvious signs of

damage (i.e. cracks in samplers, tubing broken or pinched, etc). Thus, the mPFA was brought

back to the lab for subsequent sampling at each depth.

CH4 concentrations in the OLW averaged 0.0014 ± 0.0008 mM (Figure 4a), which is well

below saturation at in situ pressures and temperatures (i.e., 65 mM; [Duan and Mao, 2006]. Two

CH4 concentration spikes occurred during the 9-months (Figure 4a, two shaded regions), which

reached 0.014 mM on 7 February 2010, and 0.004 mM on 23 February 2010.

Close to and within the sediments, CH4 concentrations reached saturation values. At the

SWI, concentrations were around 25 mM at the beginning of the time-series, increased to 80 mM

around December 2009 and ranged between 60 and 85 mM to the end of the deployment (Figure

4b). In mid-January 2010, concentrations reached as high as 85 mM then decreased to near

saturation when the second OLW CH4 spike occurred. At 7 cmbsf, CH4 concentrations were

11

below saturation at the beginning of the time series, until about February 2010 when

concentrations reached saturation of 65 mM (Figure 4c), which coincided with the OLW CH4

spike. Concentrations decreased to ~50 mM for the rest of the time-series.

CH4 stable carbon isotopes (δ13

C-CH4) were measured for the SWI and pore-water

samples. In the beginning of the time series, values for the SWI were about -53‰ and decreased

steadily to ~ -64‰ over 4 months until December 2009 (Figure 4d). At this time, the values

increased at a much faster rate to about -61‰ and then averaged about -60‰ for the rest of the

time series. The δ13

C-CH4 values for 7 cmbsf showed a similar trend, with a little more

variability (Figure 4e). The values started at around -35‰, decreased to ~ -67‰ until December

and then increased steadily with a few peaks over the rest of the record. CH4 isotopes were not

measured for overlying water because concentrations were too low.

Chloride (Cl-) concentrations were measured in the bottom waters and in pore-fluids

(Figure 4f-h). The first three months of the OLW sampler gave inconsistent salinity data, thus

we concluded the data was compromised and this part of the OLW time-series was eliminated.

For the rest of the OLW time-series, concentrations were 525 ± 15 mM. At the SWI,

concentrations were similar, and averaged 526 ± 10 mM. At 7 cmbsf, values averaged 526 ± 13

mM.

To determine temporal variability in microbial activity, sulfate (SO42-

) concentrations

were measured in the OLW, at the SWI, and at 7 cmbsf. In the OLW coil, SO42-

concentrations

were around 28 mM, typical of seawater. The SWI coil shows the SO42-

concentrations were

initially low, between 2 to 8 mM and then increased to near seawater values of 25 mM around

December 2009 (Figure 4g). The timing of this increase did not coincide with the OLW CH4

spikes. However, at the same time of the first CH4 spike, the SO42-

concentrations decreased to

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around 20 mM and then recovered back to 25 mM after about a month. At 7 cmbsf, SO42-

concentrations showed even more variability, with three distinct oscillations, each lasting about

1.5 months (Figure 4h). The timing of one of these oscillations corresponded with an OLW CH4

spike.

Dissolved inorganic carbon (DIC) stable isotope ratios (δ13

C-DIC) were measured to

determine the influence of microbial processes. DIC is produced when organic matter or CH4 is

microbially degraded, but it is also consumed through carbonate reduction methanogenesis to

form CH4 [Whiticar, 1999]. The δ13

C-DIC value can be helpful in deciphering these processes

because DIC produced from organic matter degradation has a δ13

C value typically around -22‰

and when produced from CH4, it is much more isotopically depleted in 13

C, or more negative

[Whiticar, 1999]. For reference, the δ13

C-DIC value for overlying water is typically around 0‰.

For the OLW samples, the δ13

C-DIC values were around 0‰ from November to the end

of the time-series (Figure 4i). At the SWI, the δ13

C-DIC values were much more depleted in 13

C

to around -40‰ which suggests a substantial contribution in CH4-derived carbon (Figure 4j).

However, two spikes in the δ13

C-DIC values are observed at and right after the two OLW CH4

spikes (gray shaded regions in figure 4j). This suggests that seawater is being advected or

pumped downward because its value is around 0‰. For 7 cmbsf, the δ13

C-DIC values were

between -30‰ and -40‰ and showed a slight increase in values during the first OLW CH4 spike

(Figure 4k), but were not nearly as prominent as the SWI.

Ethane and propane concentrations were also measured during the time-series (Figure 5).

Ethane concentrations at the SWI started at ~0.0002 mM and slowly increased to 0.04 mM in

December, decreased to 0.02 mM over the next month, increased back to 0.04 mM right before

the first water column spike event, was lower through this event and recovered to the end of the

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time-series (Figure 5a). For propane, concentrations were an order of magnitude lower than

ethane, and showed slight variability over time (Figure 5a). The ratio of CH4 to ethane+propane

was around 2000, decreased to 1500 by December, increased sharply to 2000 in late December

2009 and then decreased the rest of the time-series (Figure 5b). For 7 cmbsf, ethane

concentrations increased gradually to 0.03 mM, increased quickly to 0.04 mM right before the

second water column CH4 spike, remained at this value, and then decreased back to 0.03 mM

(Figure 5c). For propane, concentrations gradually increased over the time-series from <0.001

mM to 0.0015 mM (Figure 5c) and the gas ratios decreased from 2000 to 1500 (Figure 5d).

4. Discussion

CH4 concentrations from overlying water (OLW), at the sediment-water interface (SWI),

and 7 cmbsf were measured over a 9-month period from a CH4-bearing seep off Vancouver

Island, British Columbia. Porewaters were nearly CH4 saturated at the SWI and were

supersaturated at 7 cmbsf. Several measured chemical parameters (CH4, sulfate, dissolved

inorganic carbon) changed over time suggesting a potential coupling between pore-fluid

movement, microbial processes, and physical factors.

4.1. Do earthquakes influence CH4 flux from sediments?

We explored our original hypothesis that earthquakes have a significant influence on CH4

flux from sediments to the water column in the Northern Cascadia Margin. For the purpose of

this paper we have limited our analyses to timing and distribution of local earthquakes within the

vicinity of the study area, as well as timing of tele-seismic events (and their tsunamis) in the

circum-Pacific of magnitude 7.0 and above.

Local earthquakes were queried from “Earthquakes Canada” online search engine

14

(http://www.earthquakescanada.nrcan.gc.ca/) within a 300 km radius of Bubbly Gulch (Figure

6). This distance was chosen arbitrarily. During the time-series, there were 842 earthquakes

(Figure 6a). The largest occurred on 12 January and 7 May 2010 and were magnitude 4.4 and

4.5, respectively. Using the entire earthquake data set, there was no correlation between CH4

being released from the seafloor and earthquake magnitude (Spearman’s rho = -0.017, P-value =

0.081) or distance to the earthquake (Spearman’s rho = -0.007, P-value = 0.92, Figure 6b).

During the timing of the two spikes of CH4 to the OLW, 7 and 23 February 2010, there

were two earthquakes but they were magnitude 1.8 (40 km away from Bubbly Gulch) and 1.6

(78 km away from Bubbly Gulch), respectively, and likely did not contribute to significant

shaking at the mPFA site. As seen from the earthquake distribution map (Figure 6a), most

earthquake activities with magnitude above 3.0 were more than 80 km away from the mPFA site

and along the main transform fault zones (Nootka, Sovanco). Earthquake activities closer to the

mPFA site were on the shelf (and further east across Vancouver Island) but were mostly of

magnitude 1.0 - 2.0 and occurred at greater depths (> 20 km) within the crust. The accretionary

prism itself is seismically quiet, which also has been verified during a long-term passive seismic

monitoring experiment in summer of 2010 [Scherwath et al., 2011]. Therefore, there is no

strong correlation between methane flux and earthquake activity at Bubbly Gulch.

4.2. Alternative explanations of physical processes controlling variable CH4 flux

4.2.1. Earthquakes were not strong enough. Our data do not provide support for the

hypothesis that the observed CH4 releases from the seabed at Bubbly Gulch are related to

earthquake activity. However, the earthquakes that occurred during the time-series were fairly

minor events. Previous reports which attributed elevated bottom water CH4 concentrations to

earthquakes were associated with magnitude ≥4 events [e.g., Mau et al., 2007; Lapham et al.,

15

2008]. Such reports suggest that an alternative explanation for the lack of correlation of

earthquakes in our study is that the magnitudes of earthquakes that occurred during the time-

series were too small. This would suggest a threshold level of earthquake activity that controls

CH4 release.

4.2.2. Surface waves control CH4 flux. An extension of our original hypothesis is that

CH4 release is linked to tele-seismic events and their surface waves. Tele-seismic events of

magnitude 7.0 and larger could create large enough surface waves that affect local gas-charged

sediments (Gary Rogers, Natural Resources Canada, personal communication). We therefore

queried the worldwide earthquake catalogue (online USGS data base:

http://earthquake.usgs.gov/earthquakes/eqinthenews/) and selected all events of magnitude 7.0

and above. A total of 21 events were found with two large earthquakes of magnitude 8.1 off

Samoa (29 September 2009) and 8.8 off Chile (27 February 2010). Both these earthquakes

created a measurable tsunami off Vancouver Island and were clearly recorded in all bottom-

pressure recorder data connected to the NEPTUNE Canada cable [e.g. Thomson et al., 2011].

The 8.8 event off Chile corresponded to the second OLW CH4 spike (Figure 4). At 7 cmbsf,

right after the second OLW CH4 spike, CH4 concentrations decreased which could be interpreted

as a single "burp"-like event with a shallow CH4 release into the water column. Right after this

degassing event, seawater was pulled into the sediment as seen in the increase in sulfate

concentrations and an increase in the 13

C-CH4 record at the SWI and at 7 cmbsf. However,

equally large (or larger) changes in all measured chemical constituents also occurred across the

period of observation without any coincident tele-seismic events (especially the spike in CH4 in

the OLW early in February 2010). Extending the test to all 21 selected tele-seismic events

showed no further evidence for any correlation between those events and the pore-fluid record.

16

Especially in the period between the beginning of the record in August and early December of

2009, where no sudden activity was detected in the pore-fluids, 9 earthquakes of magnitude 7.0

and above occurred in the circum-Pacific region and yet no large changes could be identified in

the pore-fluid record. Apparently surface waves do not obviously exert a strong control on CH4

flux. It is also possible that the local geological structure of the sampling site and the relative

orientation of the surface wave arrivals and associated patterns of seafloor deformation directly

at the sampling site are possible influencing parameters, but the data set does not include

sufficient amounts of data and co-existing observations from pressure-recorders of seismometers

to finally address this potential relationship.

4.2.3. Oceanographic events. We tested whether or not local oceanography controlled

CH4 release from the seabed, mainly related to bottom water temperature variations. Because the

solubility of methane decreases with warmer temperatures, the correlation here would be

increased bottom water temperature increases the CH4 flux from the seafloor. The temperature

record from the mPFA showed a ~2 week periodicity, but overall the temperatures decreased

from 3.00 to 2.75ºC over 5 months from August to December, then increased at a faster rate to

~3.05°C until February (Figure 7a). In early February, there was a sharp drop in temperature

from 3.05 to 2.70ºC within a week, which recovered to about 2.80°C within a week and stayed

constant until mid-March. From this point on, the typical 2-week periodicity returned but two

smaller sudden drops in temperature occurred with about half the magnitude as the main event in

February. There were no surface seawater temperature anomalies during this time period

(supplemental Figure 1).

To verify the regional extent of this bottom water temperature record, a temperature

record was also obtained from ~750-m away near the Bullseye Vent site using NEPTUNE

17

Canada’s Bottom Pressure Recorder (BPR), which was intended as a tsunami monitoring device

[NEPTUNE, 2011]. The BPR at Bullseye Vent sits at 1,258 m water depth, 6 m shallower than

Bubbly Gulch. The temperature here was a few tenths of a degree warmer than Bubbly Gulch,

probably due to the depth difference, and also exhibited the same pattern, including the

temperature drop in February (Figure 7a). This sudden drop in seafloor temperatures appears to

correspond to the first large methane spike in the SWI sampler (Figures 4 and 7). It is unclear

why CH4 flux would increase with a temperature decrease.

One possible explanation for the increased CH4 fluxes could be the dissociation of gas

hydrate within the sediments. In the Gulf of Mexico, a temperature increase was correlated to an

increase in the bubble volume from a gas seep due to hydrate dissociation [MacDonald et al.,

2005]. However, our time-series shows a decrease in temperature, which would have stabilized

the shallow hydrate even more, and does not support the explanation of a CH4 spike from

dissociating hydrate.

4.2.4. Seasonal storm pattern on West Coast off Vancouver Island. Pressure decreases

can also stimulate gas hydrate dissociation, and thus CH4 flux. While the impact of seafloor

pressure on gas hydrate has generally been viewed as a long-term effect [Paull et al., 1991],

short term variations may occur. So, the bottom pressure data was analyzed for any anomalous

events, such as occurrence of seasonal storms (supplemental material figure 2). Typically, strong

storms occur during the winter months off Vancouver Island from September/October to

March/April. These storms last several days and together with large pressure changes, they do

increase wave action and thus a pressure signal in the water column. Storms can be easily

identified by a much larger energy in the frequency spectrum obtained from the BPR data,

especially in the period-range above 50 seconds (Martin Heesemann, NEPTUNE-Canada, and

18

Earl Davis, Natural Resources Canada, personal communication). The largest storm event

happened in early November and lasted for about 4 days from 6 November to 10 November 2009

(see supplemental material figure 2). There were no other anomalous bottom water pressure

changes during the time period as recorded by two different instruments at Bullseye Vent as part

of NEPTUNE Canada’s monitoring (Figure 7b). Thus pressure changes from such storm events

do not appear to explain the two peaks in CH4 concentration measured in the OLW during

February 2010.

4.2.5. Suggestions on possible controlling factors not tested. From our study, we can

conclude that there is no correlation between methane flux out of the seabed at Bubbly Gulch

and the parameters we tested (earthquakes, surface waves, bottom water temperature, and storm

activity). The bottom water temperature drop did correlate to the first CH4 spike, yet it is unclear

how that works. A factor that was not tested was bottom currents. Recent work has suggested a

relationship between bottom currents and CH4 release from the seabed at a nearby gas hydrate

site [Thomsen et al., 2012]. Unfortunately the bottom water currents were not monitored

simultaneously with the mPFA measurements. However, an Acoustic Doppler Current Profiler

(ADCP) installed on the NEPTUNE Canada cable did monitor currents during the month of May

2010 with the broad-band seismometer at Bullseye Vent (~750 m west of the mPFA site). This

ADCP allowed us to verify that the bottom currents are mostly tidal dominated (data not shown).

The pore-fluid data from the mPFA are not sampled at high enough frequency to resolve tidal

cycles, as each data point represents an average condition over a 4 day period. In order to

resolve these remaining possibilities, higher frequency sampling with the mPFA is required.

4.3. Sedimentary microbial processes

19

The time-series dataset presented here is unique, and gives us an opportunity to monitor

how variable CH4 fluxes might influence sedimentary microbial processes. The variations in

sulfate concentration captured at Bubbly Gulch suggested seawater was periodically drawn into

the sediment pore-fluids. This observation was also supported by the δ13

C-DIC time-series data

(Figure 4j). Overlying water had a δ13

C-DIC value around 0‰, which was mixed with the pore-

water DIC of -40‰ to yield an average value around -20‰. A correlation between the first

methane spike and the heavier δ13

C-DIC value was observed, but did not hold for the second

methane spike. Admittedly, the second CH4 spike was not as strong as the first. This pattern of

heavier DIC was similar at 7 cmbsf, yet the signal was not as strong (Figure 4k). This active

pumping of seawater down into pore-waters has several implications discussed below.

4.3.1. Implications of overlying water pumping into seawater. Since sulfate is the main

electron acceptor for organic matter mineralization and anaerobic CH4 oxidation, this renewal in

supply suggests microbial communities are no longer dependent solely upon diffusion to supply

more sulfate. Bioirrigation processes have also been shown to resupply sulfate to these

communities [e.g. Fossing et al., 2000] but there were no conspicuous bioirrigators (clams,

tubeworms, etc.) visible on the seafloor at Bubbly Gulch during the deployment. At a southern

Cascadia gas hydrate site, Tryon et al. [1999] found that periodic changes in fluid flow

directions, apparently controlled by episodic gas release, draw seawater (and thus sulfate) into

the sediments. According to their fluid flux model, when the sample collection began at Bubbly

Gulch it was at a stage where gas vents were active through a buoyancy-driven gas discharge

event. Over time, the system relaxed back to a stage where the gas built up in the deeper

reservoir until another event released it.

20

The oscillations in the advective flow direction will impact the microbial community as

sulfate is pumped down and CH4 released. We saw an indication of this in the data at the SWI

(Figure 4). Thus, the essential components required for microbial anaerobic oxidation of CH4

(AOM) are resupplied within these sediments at a rate that greatly exceeds replenishment via

diffusion. Such pumping was also suggested at mud volcano sites in the Gulf of Mexico [Joye et

al., 2005]. One implication for more sulfate being pumped into the sediments could be that more

CH4 will be oxidized through AOM.

Seawater pumping will also infuse oxygen (O2) into the sediment. O2 is the highest

energy yielding process for organic matter remineralization [Froelich et al., 1979]. With more

O2, rates of organic matter decomposition should also increase, along with aerobic CH4

oxidation, since CH4 concentrations are so high at the sediment-water interface. Such further

implications need to be addressed at finer temporal resolution. The implications mentioned for

the seawater pumping need to be addressed with more focus and directed research projects.

4.3.2. Methane source. Using stable carbon isotopes, we show that the CH4 measured at

Bubbly Gulch was predominately from microbial methanogenesis, as opposed to thermogenesis.

CH4 with carbon isotope values less than -50‰ indicated a predominately biogenic origin

[Bernard et al., 1977]. This was consistent with what was measured at the nearby Bullseye

Vent, where CH4 was also shown to be biogenic using a dual stable isotope approach between

carbon and hydrogen [Riedel et al., 2006; Pohlman et al., 2009b; Pohlman et al., 2009a]. There

was an apparent inverse relationship between methane concentration and the stable isotope value

(supplementary materials figure 3), although it was not strong (Spearman’s rho = -0.411, P-value

= 0.000247 for SWI). Bubbly Gulch δ13

C-CH4 values were within this biogenic range (all values

21

were between -55 and -70‰) and ~99% of the dissolved gases consisted of CH4. The temporal

variability of these higher hydrocarbon gases also behaved similarly to the CH4 concentrations.

5. Conclusions

From a gas seep off Northern Cascadia Margin, a long-term sampling device collected overlying

water and pore-fluid samples from 25 cm above seafloor, at the sediment-water interface (SWI),

and 7 cmbsf over a 9-month period (August 2009-May 2010). The source of this gas was found

to be predominantly biogenic, with measurable amounts of ethane and propane. Results showed

temporal variability in in situ CH4 concentrations as well as other chemical parameters,

suggesting a complex interaction between microbial responses and a still unidentifiable outside

physical factor (or factors). Possible controls on this temporal variability from seismic activity

(local and tele-seismic events), regional oceanography, storm-weather patterns, and microbial

activity were considered. The CH4 flux from the seabed was variable over time but a single

source or physical driver for this flux was not identified. Future studies should focus on higher

resolution sampling to address tidal variations and bottom water currents. While the temporal

resolution was not high enough to resolve the tidal or current controls, it was sufficient to begin

to assess how sedimentary microbial processes might be affected by the variable methane flux.

This work also highlights the importance of online-observatories or lander-deployments to obtain

higher temporal resolution [e.g. Friede et al., 2003; Kasaya et al., 2009; Barnes et al., 2011].

Acknowledgements

This work was supported by many groups giving in-kind support. Specifically, we would like to

thank NEPTUNE Canada, the pilots of ROVs ROPOS and Doc Ricketts, Captain and crews of

the R/V Thomson, R/V Western Flyer, and R/V Tully for graciously deploying and retrieving the

22

mPFA. The David and Lucile Packard Foundation provided support. We also thank the generous

support of Dr. Peter Brewer from MBARI for time on the Pacific Northwest Cruise. Claire

Langford helped with laboratory analysis of all water samples. Laura Lapham was supported by

the DOE Gas Hydrate Post-doctoral fellowship, the Center for Geomicrobiology at Aarhus

University, and by a grant (in part) from BP/the Gulf of Mexico Research Initiative to support

consortium research entitled "Ecosystem Impacts of Oil and Gas Inputs to the Gulf (ECOGIG)"

administered by the University of Mississippi during the preparation of this manuscript (GRIIDC

ID R1.x132.134:0041). We also thank Martin Heesemann, NEPTUNE-Canada, and Earl Davis,

Natural Resources Canada, for thoughtful discussions.

23

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Figure Captions:

Figure 1: A) Map of NEPTUNE Canada cabled observatory, with the ODP 889, Bullseye Vent, node

circled. B) Close-up of ODP 889 node site, showing location of Bubbly Gulch, mPFA, and other seafloor

instrumentation. Basemap is AUV bathymetry. U1328 = IODP borehole, BBS = Broad Band

seismometer, JB = NEPTUNE Canada junction box, BPR = Bottom Pressure Recorder, and mPFA =

mini-PoreFluid Array.

Figure 2: Seafloor photographs of Bubbly Gulch, the exact site where the mini-Pore Fluid Array (mPFA)

was deployed in 2009 and retrieved in 2010. For scale, the mPFA gray box stands 75 cm tall. In 2009,

A) the seafloor looks freshly cracked and a thin layer of brown mud sits atop the gray clays (inset). B) A

close-up photo of probe tip on edge of crack. In 2010, C) the cracks have mostly been filled with

sediment and clams are more prevalent. D) Photo showing position of probe tip in cracks. Photos

courtesy of ROV Doc Ricketts, MBARI.

Figure 3: A) Seafloor picture of the mini-PFA (gray box) on the seafloor with ROV arm placing the

white PVC stick in the mud, which is the sampling probe tip. The white PVC rod in the gray box controls

the valve handle. B) Drawing of the OsmoSampler assembly within the box and the sample intervals

along the PVC stick in the mud. Drawing shows just one depth plumbed. Thin tubing connects the

sampling ports to the OsmoSamplers within the mPFA box. mPFA contains three OsmoSamplers: two

connected to valve as shown and the third, for OLW, bypasses the valve. Sample is collected through the

ports in the overlying water (OLW), at the sediment-water interface (SWI), and at 7 cm below seafloor

(cmbsf). Seafloor photo courtesy of ROV Doc Ricketts, MBARI.

Figure 4: Methane concentrations (CH4, a-c), stable carbon isotopes of methane (δ13C-CH4, d-e), chloride

(Cl-) and sulfate (SO42-) concentrations (f-h), and δ13C-CH4 (i-k) from August 2009 to May 2010 for

overlying water (OLW, first row), sediment-water interface (SWI, second row) and 7 cmbsf (third row).

In e, the δ13C-CH4 value in the early record is -34‰ which is off-scale. Shaded regions show the timing

of two methane concentration spikes.

Figure 5: Ethane and propane concentrations and concentration ratios for SWI (a and c) and for 7 cmbsf

(b and d). Shaded regions show the timing of two methane concentration spikes.

Figure 6: A) Distribution of earthquakes within 300 km of Bubble Gulch (purple dot). The blue line

shows the backbone of the NEPTUNE Canada cabled observatory. B) Correlation plots between methane

released into water column and earthquake magnitude and distance.

Figure 7: A) Bottom water temperature from Bubbly Gulch (thick black line) and Bullseye Vent (gray

line). B) Bottom water pressure recorded from Bullseye vent using BPR (black) and CTD (red line).

Shaded regions show the timing of two methane concentration spikes.

All supplemental figures and tables are given in this file.

Supplementary figure 1: Sea-surface temperature for 4 years spanning across our data collection time. The gray box shows when the methane data was collected. Satellite sea-surface temperature data was acquired through the NOAA CoastWatch browser database.

 

Supplemental figure 2: Power-spectrum of the bottom-pressure recorder (BPR) data from NEPTUNE-Canada (image courtesy of M. Heesemann and E. Davis). Shown is the intensity of the pressure record (red color represent high intensity, blue color represent low intensity) over the period of the mPFA deployment in 2009 to 2010. Bottom axis is time (labels are day/month) and Left-hand axis is the period (in seconds) of the pressure data. Also identified by arrow are the times of the two large earthquakes off Samoa and Chile, that created large tsunamis. Small black vertical dashed lines highlight occurrence of major storms that lasted for more than 24 hours.

 

Supplemental figure 3: Relationship between stable isotope value and methane concentration between SWI (closed squares) and 7 cmbsf (open triangles). Linear fit lines and equations are shown. For SWI, Spearman’s rho = -0.411, P-value 0.000247. For 7cmbsf, Spearman’s rho = -0.28, P-value 0.02.

Supplemental figure 4: Relationship between ethane and propane of both sediment water interface (SWI, open sideways triangle) and 7 cmbsf (filled diamonds).

Supplementary table 1: Methane concentrations, stable isotopic composition for methane and dissolved inorganic carbon (DIC), chloride, sulfate, ethane, and propane concentrations for all data presented in paper.

Depth Date Methane (mM)

δ13C-CH4 (‰)

δ13C-DIC (‰)

Chloride (mM)

Sulfate (mM)

Ethane (mM)

Propane (mM)

OLW 11/5/2009 0.00276 0.4 526.23 26.96 11/9/2009 0.00187 0.5 527.2 26.98 11/13/2009 0.00146 -0.7 11/17/2009 0.00156 0.1 11/21/2009 0.00103 -0.6 529.34 27.14 11/25/2009 0.00129 -0.1 523.76 26.72 11/29/2009 0.00111 0.5 521.84 28.13 12/3/2009 7.40E-04 -0.4 515.47 26.55 12/7/2009 0.00107 -0.2 518.68 26.75 12/11/2009 0.00102 -0.2 520.7 28.22 12/15/2009 -- -0.2 527.09 27.04 12/19/2009 8.80E-04 -- 526.48 27 12/23/2009 0.00119 -0.6 528.37 28.22 12/27/2009 -- -0.5 521.93 28.32 12/31/2009 0.00126 -0.4 520.75 26.84 1/4/2010 -- -0.3 509.35 27.42 1/8/2010 0.00124 -0.2 511.73 27.92 1/12/2010 0.0011 -0.2 512.99 27.02 1/16/2010 8.90E-04 -0.8 512.41 26.88 1/20/2010 -- -0.7 520.47 27.77 1/24/2010 6.20E-04 -1.2 519.01 26.73 1/28/2010 9.30E-04 0.3 512.92 27.87 2/1/2010 0.00124 0.2 519.09 27.24 2/5/2010 0.01354 0.2 514.24 27.05 2/9/2010 0.0018 0.2 499.08 26.48 2/13/2010 0.00128 0.7 510.24 26.25 2/17/2010 9.80E-04 -0.2 526.43 26.85 2/21/2010 9.30E-04 0.1 511.63 26.37 2/25/2010 0.00101 0.4 511.72 26.95 3/1/2010 0.00366 -0.1 508.21 26.11 3/5/2010 1.00E-03 -0.7 513.54 26.39 3/9/2010 8.00E-04 0.1 550.15 27.82 3/13/2010 0 -0.1 546.86 27.59 3/17/2010 0.00158 -0.5 522.31 28.06 3/21/2010 0.00117 -0.3 541.24 28.84 3/25/2010 9.20E-04 -1.7 538.16 28.95

3/29/2010 0.00136 -1.4 552.01 29.57 4/2/2010 0.00107 0.6 536.53 28.97 4/6/2010 0.00116 0.2 545.34 27.56 4/10/2010 9.40E-04 -0.1 539.22 28.58 4/14/2010 9.70E-04 -0.1 521.18 27.85 4/18/2010 7.10E-04 -1.2 545.01 28.8 4/22/2010 0.00104 -0.1 542.56 28.91 4/26/2010 0.00113 -0.4 544.45 27.53 4/30/2010 0.00105 -0.1 535.51 28.49 5/4/2010 0.00214 0 535.76 28.42 5/8/2010 0.00181 -0.6 530.09 28.4 5/12/2010 0.00152 -1.1 519.1 27.52 SWI 8/9/2009 0.0029 2.00E-04 8/13/2009 0.0104 3.00E-04 8/17/2009 0.017 2.00E-04 8/20/2009 25.4 -52.6 -42.7 543.4 7.5 0.0192 2.00E-04 8/24/2009 25.4 -52.6 -42.7 543.4 7.5 0.0182 3.00E-04 8/28/2009 35.9 -56.1 -40.9 534.3 6 0.0217 4.00E-04 9/1/2009 39.2 -58 -40 0.023 5.00E-04 9/4/2009 42.4 -58.7 -40.1 0.0032 5.00E-04 9/8/2009 45.7 -59.1 -40.1 528.3 5.3 0.0264 5.00E-04 9/12/2009 43.2 -59.1 -39.8 0.0258 6.00E-04 9/15/2009 53.1 -59.1 -40.2 0.0251 5.00E-04 9/19/2009 55.7 -59.2 -41.4 0.0329 7.00E-04 9/23/2009 55.3 -60 -41.5 0.0338 8.00E-04 9/27/2009 52.9 -60.3 -40.8 531.3 6.9 0.0165 4.00E-04 9/30/2009 50.7 -59.7 -39.6 507.6 6.1 0.0288 7.00E-04 10/4/2009 66 -61.1 -40.4 529.2 6 0.0302 7.00E-04 10/8/2009 66.5 -61.5 -40.2 529 6.1 0.0377 1.00E-03 10/11/2009 32.6 -61.8 -39.8 527.6 5.6 0.0319 8.00E-04 10/15/2009 54 -62.1 -38.4 533.5 4.5 0.0303 7.00E-04 10/19/2009 57.1 -62.6 -38.2 524.4 4.8 0.0346 8.00E-04 10/23/2009 71.6 -63 -37.6 520.8 4.1 0.0358 9.00E-04 10/26/2009 60.3 -62.8 -38.3 524.1 4.5 0.0346 9.00E-04 10/30/2009 55.5 -63.1 -38 527.5 3.9 0.0349 9.00E-04 11/3/2009 63.8 -63.1 -37.7 533.9 3.7 0.0374 1.00E-03 11/7/2009 65.1 -63.5 -37.9 531.2 3.4 0.0433 0.0012 11/10/2009 63.9 -63.7 -37.7 534 3.4 0.0416 0.0011 11/14/2009 64.1 -64 -37.4 0.0405 0.0011 11/18/2009 68.6 -63.5 -36.6 529.2 2.8 0.0437 0.0012 11/21/2009 78.4 -63.7 -36.9 522.2 3.1 0.0433 0.0013 11/25/2009 75.5 -63.8 -36.8 524.4 3 0.0434 0.0012 11/29/2009 73.5 -63.9 -36.6 521.9 3 0.0404 0.0011 12/3/2009 72.6 -64.3 -36.9 532.8 2.6 0.0446 0.0013

12/6/2009 79.6 -64.1 -37.7 529.9 3.1 0.0442 0.0013 12/10/2009 78.9 -63.3 -38.4 528.5 10.2 0.04 0.0012 12/14/2009 74.9 -62.7 -39.1 538.8 15.9 0.0312 1.00E-03 12/17/2009 64.1 -61.7 -37.8 523.7 16.7 0.0348 12/21/2009 75.2 -61.4 -37.5 529 16.1 0.0258 1.00E-03 12/25/2009 64.4 -61.3 -33.9 526.3 21.5 0.0276 0.0012 12/29/2009 71.2 -61 -31.4 516.2 22.2 0.0239 8.00E-04 1/1/2010 57.3 -61 -37.7 536.2 17.3 0.0249 8.00E-04 1/5/2010 62.6 -61.1 -36 536.3 20.1 0.0352 0.0013 1/9/2010 81.4 -60.6 -30.1 522.3 23.5 0.039 0.0028 1/12/2010 84.6 -60.3 -35.9 537.1 19.1 0.032 9.00E-04 1/16/2010 70.5 -60.8 -35.7 528.1 18.9 0.0396 0.0018 1/20/2010 84.6 -60.2 -33.3 537.3 22 0.0348 1.00E-03 1/24/2010 73.7 -60.2 -32.5 506.6 25 0.0407 0.0011 1/27/2010 86.3 -60.3 -33.4 534.2 22.1 0.0296 7.00E-04 1/31/2010 81.2 -60.5 -23.4 507.4 24 0.0378 0.0011 2/4/2010 61.9 -60.6 -24.4 511 24.2 0.0283 7.00E-04 2/8/2010 66.8 -60.3 -20.4 526.5 25.3 0.0314 9.00E-04 2/11/2010 59.4 -60.5 -26 526.5 26.1 0.0278 8.00E-04 2/15/2010 54.5 -60.2 -36.3 531.5 23.6 0.0255 7.00E-04 2/19/2010 62.1 -59.9 -36.3 510.5 21.7 0.0305 9.00E-04 2/22/2010 57 -59.8 -38.1 544.7 21.9 0.0319 9.00E-04 2/26/2010 63.2 -60.1 -36.9 514.3 21.6 0.031 0.0012 3/2/2010 59.7 -59.7 -37.7 523.4 21.2 0.0284 1.00E-03 3/6/2010 65.3 -59.3 -39 524.7 18.7 0.0326 0.0015 3/9/2010 68.2 -59.7 -38.5 534.7 19.7 0.0349 0.0014 3/13/2010 73 -59.6 -37.8 513.5 17 0.0374 2.00E-04 3/17/2010 70.5 -60.1 -31 500.6 23.7 0.0368 0.0015 3/20/2010 65.6 -60.2 -23.2 532.4 26.4 0.033 0.0012 3/24/2010 59.9 -59.6 -24 510.9 25.5 0.032 9.00E-04 3/28/2010 76.5 -58.4 -21 509.3 26.9 0.0401 0.0013 4/1/2010 64.2 -59.1 -30.3 521.6 25 0.036 9.00E-04 4/4/2010 67.3 -58.6 -39.3 530 20.4 0.039 0.0011 4/8/2010 74.2 -59.2 -41 537.4 14 0.0431 0.0014 4/12/2010 74.7 -59.8 -41.4 538.9 11.2 0.0432 0.0014 4/15/2010 75.6 -60.1 -41.1 522.2 9.2 0.0442 0.0015 4/19/2010 70.2 -60.6 -42.4 0.041 0.0013 4/23/2010 73.4 -60.7 -41.8 0.0038 0.0015 4/27/2010 73.3 -60.1 -41.2 0.0433 2.00E-04 4/30/2010 56 -60.1 -41.1 0.0328 0.0011 5/4/2010 58 -60.3 -40.7 0.0348 0.0013 5/8/2010 63.5 -60.3 -40.5 0.0383 0.0014 5/12/2010 68.7 -61.4 -39.6 0.042 0.0016 7 8/9/2009 -15.91

cmbsf 8/13/2009 0.12 -57.32 -8.48 8/17/2009 -31.35 553.57 24.49 8/21/2009 0.82 -34.1 8/25/2009 9.79 -51.5 558.25 12.11 8/29/2009 14.56 -56.9 9/2/2009 20.11 -59.9 9/6/2009 23.86 -61.1 542.91 8.08 9/10/2009 24.69 -61.7 9/14/2009 26.46 -62.8 516.31 11.48 9/18/2009 40.16 466.72 10.63 0.01888 3.10E-04 9/22/2009 41.2 525.75 11.76 0.02009 3.60E-04 9/26/2009 39.77 524.08 11.68 0.02006 3.60E-04 9/30/2009 42.2 527.19 11.48 0.0219 4.10E-04 10/4/2009 43.49 519.5 11.35 0.02294 10/8/2009 43.93 -61.91 -36.56 547.95 10.11 0.02386 4.90E-04 10/12/2009 43.98 -62.11 -36.61 526.41 9.91 0.02418 5.90E-04 10/16/2009 45.48 -62.33 -36.08 517.04 9.12 0.02548 5.10E-04 10/20/2009 44.99 -63.36 -37.01 519.47 8.95 0.02557 5.30E-04 10/24/2009 47.03 -63.24 -37.4 509.01 9.16 0.02709 6.00E-04 10/28/2009 46.4 -64.34 -36.92 520.67 9.35 0.02712 6.30E-04 11/1/2009 48.1 -64.34 -36.38 541.56 9.39 0.02755 6.30E-04 11/5/2009 48.51 -64.74 -36.59 549.49 9.18 0.02817 6.60E-04 11/9/2009 50.69 -64.51 -36.89 540.61 9.21 0.0296 7.10E-04 11/13/2009 51.06 -65.48 -38.12 522.2 8.86 0.02957 7.10E-04 11/17/2009 48.57 -65.7 -37.54 524.38 8.69 0.02894 7.00E-04 11/21/2009 56.67 -65.65 -37.15 524.55 8.21 0.03482 8.80E-04 11/25/2009 56.52 -65.64 -38.49 535.46 7.89 0.82722 9.90E-04 11/29/2009 45.12 -67.61 -37.98 504.82 7.23 0.0278 7.00E-04 12/3/2009 49.1 -67.06 -34.81 524.64 4.49 0.03062 8.00E-04 12/7/2009 48.85 -66.79 -34.66 524.76 4.03 0.03039 8.10E-04 12/11/2009 49.11 -66.54 -34.87 529.61 4.63 0.03116 8.10E-04 12/15/2009 46.98 -66.46 -38.46 532.13 9.64 0.02957 7.80E-04 12/19/2009 49.65 -66.17 -40.37 526.64 10.18 0.03091 8.10E-04 12/23/2009 51.22 -64.75 -40.39 534.17 9.36 0.03133 8.80E-04 12/27/2009 51.21 -64.03 -38.96 528.42 13.41 0.03089 8.20E-04 12/31/2009 50.93 -63.32 -38.57 513.64 11.77 0.03146 8.10E-04 1/4/2010 50.46 -63.13 -38.19 529.64 8.07 0.03241 8.30E-04 1/8/2010 47.41 -63.34 -37.94 529.82 6.92 0.03034 7.50E-04 1/12/2010 52.61 -63.81 -37.67 537.25 6.55 0.03289 8.20E-04 1/16/2010 52.58 -64.05 -37.07 507.91 5.63 0.03319 7.80E-04 1/20/2010 48.47 -64.14 -36.73 521.67 5.74 0.03048 6.80E-04 1/24/2010 51.59 -64.26 -35.77 537.85 6.04 0.03365 1/28/2010 63.95 -64.46 -35.41 523.62 8.32 0.04071 9.90E-04 2/1/2010 60.48 -63.99 -35.4 533.28 10.7 0.03824 9.00E-04

2/5/2010 61.34 -63.48 -33.99 534.63 10.38 0.03929 8.90E-04 2/9/2010 60.32 -63.5 -33.37 518.65 13.46 0.03895 8.90E-04 2/13/2010 59.79 -63.34 -32.53 517.8 15.65 0.03933 9.10E-04 2/17/2010 55.22 -63.2 -32.9 519.93 16.4 0.03823 8.50E-04 2/21/2010 56.81 -62.71 -33.66 520.22 15.84 0.03879 8.70E-04 2/25/2010 58.51 -62.67 -34.26 522.18 16.1 0.04019 9.60E-04 3/1/2010 56.88 -62.28 -33.8 516.57 16.51 0.03899 9.50E-04 3/5/2010 59.92 -62.1 -34.72 512.72 13.93 0.0406 3/9/2010 58.92 -62.29 -35.4 520.78 11.93 0.04006 0.00108 3/13/2010 61.31 -62.99 -35.85 0.0492 0.00115 3/17/2010 50.37 -63.18 -35.51 519.62 9.55 0.03413 9.30E-04 3/21/2010 50.8 -63.16 -32.65 516.91 14.44 0.03413 9.70E-04 3/25/2010 49.1 -62.93 -34.29 529.97 14.81 0.03291 1.00E-03 3/29/2010 46.9 -62.61 -32.36 520.14 19.19 0.03158 8.40E-04 4/2/2010 50.23 -61.64 -30.22 533.51 21.36 0.03366 9.40E-04 4/6/2010 38.26 -60.8 -35.05 536.47 18.33 0.02648 6.60E-04 4/10/2010 50.16 -60.9 -33.06 528.06 19.64 0.32173 8.90E-04 4/14/2010 42.69 -60.91 -28.16 519.34 18.31 0.26869 7.60E-04 4/18/2010 50.41 -60.92 -35.62 517.32 18.34 0.30694 9.40E-04 4/22/2010 53.28 -60.77 -34.89 518.25 18.42 0.03165 9.90E-04 4/26/2010 51.53 -60.53 -35.69 538.73 15.26 0.03015 0.00108 4/30/2010 51.65 -60.65 -36.59 522.72 12.35 0.03043 0.00107 5/4/2010 48.09 -61.6 -32.23 530.24 10.52 0.02845 0.00108 5/8/2010 50.8 -61.73 -37.1 539.19 11.51 0.03064 0.00127 5/12/2010 50.42 -60.92 -35.55 537.01 11.46 0.03058 0.00156 

 

Supplemental table 2: Log of earthquakes recorded during time-series.

Date Lat Long Depth Mag Distance (km)

6/1/2010 49.083 -125.591 16.0* 0.6ML 15 6/1/2010 49.132 -128.035 10.0g 2.4Mw 152 6/1/2010 49.519 -127.243 25.7* 1.0ML 84

5/31/2010 50.468 -129.867 10.0g 2.5Mw 175 5/31/2010 49.610 -127.593 29.7* 1.4ML 107 5/29/2010 49.220 -126.035 30.0* 2.0ML 11 5/28/2010 50.203 -127.745 14.9* 0.6ML 60 5/28/2010 49.126 -127.976 10.0g 2.6Mw 149 5/28/2010 49.802 -126.846 42.2* 2.3ML 55 5/28/2010 49.800 -126.844 42.2* 1.7ML 55 5/28/2010 49.310 -123.913 60.7* 2.5ML 15 5/27/2010 49.121 -127.973 10.0g 2.2Mw 149 5/26/2010 50.229 -124.369 1.0g 1.6ML 43 5/26/2010 48.994 -128.901 10.0g 2.8Mw 217 5/26/2010 49.228 -128.048 10.0g 2.8Mw 149 5/26/2010 48.582 -128.633 10.0g 3.1Mw 208 5/26/2010 50.212 -127.645 1.0* 1.3ML 56 5/25/2010 47.570 -124.308 26.0g 1.6ML 118 5/25/2010 48.151 -124.979 19.7* 1.0ML 98 5/25/2010 49.182 -128.040 10.0g 3.1Mw 151 5/24/2010 49.084 -127.892 10.0g 2.7Mw 144 5/24/2010 49.609 -127.417 20.7* 1.7ML 95 5/24/2010 48.278 -122.900 17.3* 1.2ML 38 5/24/2010 49.735 -127.239 25.8* 1.5ML 82 5/24/2010 49.147 -127.941 10.0g 2.4Mw 146 5/23/2010 49.612 -129.858 10.0g 3.0Mw 212 5/23/2010 48.818 -128.594 10.0g 3.0Mw 199 5/23/2010 48.822 -128.566 10.0g 2.9Mw 196 5/23/2010 49.331 -125.936 37.0* 1.4ML 20 5/23/2010 48.639 -125.378 30.9* 1.1ML 36 5/23/2010 49.287 -127.865 10.0g 2.3Mw 135 5/22/2010 49.081 -128.083 10.0g 2.5Mw 157 5/22/2010 49.588 -127.486 29.5* 1.6ML 100 5/22/2010 49.278 -123.630 12.6* 0.4ML 16 5/22/2010 48.755 -123.217 14.4* 0.6ML 17 5/22/2010 48.684 -123.031 23.4* 0.5ML 27 5/22/2010 50.785 -129.118 55.7* 2.5Mw 120 5/21/2010 49.563 -127.467 28.3* 1.5ML 99 5/21/2010 49.488 -127.229 30.0* 1.8ML 84 5/19/2010 49.250 -129.724 10.0g 3.4Mw 230 5/19/2010 48.859 -124.557 41.5* 0.6ML 45

5/19/2010 48.333 -122.992 45.6* 1.1ML 29 5/19/2010 48.270 -122.906 19.2* 1.3ML 38 5/19/2010 49.447 -127.157 19.6* 1.4ML 80 5/18/2010 48.330 -128.964 10.0g 3.6Mw 241 5/18/2010 48.377 -128.804 10.0g 3.6Mw 228 5/18/2010 48.540 -128.774 10.0g 3.2Mw 220 5/18/2010 49.168 -127.977 10.0g 2.5Mw 147 5/18/2010 49.155 -127.995 10.0g 2.5Mw 149 5/18/2010 49.151 -127.952 10.0g 2.7Mw 146 5/18/2010 48.994 -123.709 49.3* 0.6ML 23 5/18/2010 48.821 -123.394 13.6* 0.3ML 19 5/17/2010 48.135 -124.624 32.0* 0.9ML 98 5/17/2010 48.852 -128.097 10.0g 2.5Mw 162 5/16/2010 48.873 -128.088 10.0g 2.5Mw 161 5/16/2010 49.989 -127.903 15.7* 1.0ML 86 5/16/2010 49.416 -129.426 10.0g 2.6Mw 202 5/16/2010 50.288 -124.016 55.0* 0.9ML 61 5/16/2010 49.100 -127.925 10.0g 2.1Mw 146 5/16/2010 49.133 -129.713 10.0g 2.8Mw 239 5/16/2010 50.086 -127.987 24.7* 1.1ML 79 5/16/2010 49.022 -128.681 10.0g 2.0ML 201 5/16/2010 49.585 -126.921 31.8* 1.2ML 60 5/16/2010 48.759 -123.048 56.8* 0.4ML 27 5/16/2010 49.124 -125.695 12.8* 0.1ML 16 5/15/2010 49.996 -127.882 14.9* 2.0ML 85 5/15/2010 48.375 -122.894 19.0* 0.6ML 35 5/15/2010 49.113 -127.901 10.0g 2.4Mw 144 5/14/2010 49.130 -128.017 10.0g 2.4Mw 151 5/14/2010 49.144 -128.012 10.0g 2.4Mw 150 5/14/2010 49.079 -125.601 18.1* 1.1ML 14 5/14/2010 49.171 -128.026 10.0g 2.5Mw 150 5/13/2010 49.302 -126.829 13.8* 1.3ML 67 5/13/2010 48.507 -124.761 29.2* 0.8ML 76 5/13/2010 49.999 -128.028 17.3* 1.8ML 89 5/12/2010 50.503 -125.356 1.0g 1.4ML 54 5/12/2010 49.128 -127.982 10.0g 2.5Mw 149 5/12/2010 50.236 -127.689 16.5* 0.6ML 55 5/12/2010 49.097 -128.112 10.0g 2.5Mw 159 5/12/2010 49.545 -127.561 26.7* 1.2ML 106 5/12/2010 49.151 -128.003 10.0g 2.3Mw 149 5/12/2010 49.171 -128.030 10.0g 2.1Mw 150 5/11/2010 49.098 -127.876 10.0g 2.3Mw 142 5/11/2010 49.126 -127.985 10.0g 2.3Mw 149 5/11/2010 49.077 -127.951 10.0g 2.6Mw 148 5/11/2010 49.138 -128.046 10.0g 2.6Mw 153 5/10/2010 49.076 -127.977 10.0g 2.4Mw 150

5/9/2010 50.220 -127.687 14.6* 0.7ML 56 5/9/2010 49.510 -126.865 25.3* 1.0ML 58 5/9/2010 49.107 -127.946 10.0g 2.6Mw 147 5/8/2010 49.132 -127.995 10.0g 2.3Mw 150 5/8/2010 49.090 -127.930 10.0g 2.4Mw 146 5/8/2010 49.090 -127.930 10.0g 0.4Mw 146 5/8/2010 49.117 -127.965 10.0g 3.0Mw 149 5/7/2010 49.472 -127.015 33.9* 1.6ML 70 5/7/2010 49.082 -128.030 10.0g 2.4Mw 154 5/7/2010 49.014 -126.052 29.4* 0.9ML 18 5/7/2010 50.131 -130.107 10.0g 2.6Mw 201 5/6/2010 48.036 -128.188 10.0g 4.5Mw 208 5/6/2010 49.938 -130.098 10.0g 2.8Mw 208 5/6/2010 50.233 -127.754 17.8* 1.0ML 57 5/6/2010 49.982 -130.110 10.0g 2.8Mw 207 5/6/2010 48.645 -123.027 22.2* 1.0ML 27 5/6/2010 50.031 -130.145 10.0g 3.3Mw 207 5/6/2010 50.010 -129.972 10.0g 2.7Mw 197 5/6/2010 48.581 -123.681 20.8* 1.1ML 22 5/6/2010 50.159 -127.878 25.3* 0.8ML 68 5/6/2010 48.584 -125.497 28.2* 1.5ML 40 5/6/2010 49.123 -128.000 10.0g 2.7Mw 151 5/6/2010 49.510 -127.273 16.2* 1.4ML 86 5/5/2010 49.114 -127.967 10.0g 2.7Mw 149 5/5/2010 49.117 -127.948 10.0g 2.7Mw 147 5/5/2010 49.123 -128.015 10.0g 2.3Mw 152 5/4/2010 49.113 -127.954 10.0g 2.8Mw 148 5/4/2010 49.031 -129.201 10.0g 2.9Mw 225 5/3/2010 51.154 -127.599 4.8* 1.9ML 52 5/3/2010 49.415 -127.168 23.6* 1.6ML 82 5/3/2010 48.966 -129.153 10.0g 3.3Mw 229 5/3/2010 49.045 -128.113 10.0g 2.8Mw 160 5/2/2010 49.147 -127.963 10.0g 2.6Mw 147 5/2/2010 49.094 -127.961 10.0g 2.8Mw 149 5/2/2010 49.303 -127.838 10.0g 2.6Mw 132 5/2/2010 49.141 -127.971 10.0g 2.7Mw 148 5/2/2010 49.137 -127.992 10.0g 2.4Mw 149 5/2/2010 49.136 -127.904 10.0g 2.7Mw 144 5/2/2010 49.452 -129.515 10.0g 3.0Mw 204

4/30/2010 48.266 -122.919 22.0* 1.5ML 38 4/30/2010 48.452 -123.304 20.6* 1.0ML 5 4/30/2010 49.155 -128.026 10.0g 2.4Mw 151 4/30/2010 49.102 -128.049 10.0g 2.5Mw 155 4/30/2010 49.031 -129.041 10.0g 3.0Mw 219 4/30/2010 50.529 -129.144 10.0g 2.4Mw 123 4/30/2010 49.058 -128.843 10.0g 2.9Mw 209

4/30/2010 49.184 -128.019 10.0g 2.4Mw 149 4/30/2010 49.557 -127.602 25.5* 1.6ML 109 4/30/2010 49.090 -127.950 10.0g 3.0Mw 148 4/30/2010 49.141 -127.989 10.0g 2.7Mw 149 4/27/2010 48.870 -127.810 10.0g 2.9Mw 141 4/27/2010 50.254 -127.689 15.5* 1.3ML 53 4/27/2010 48.927 -128.922 10.0g 3.3Mw 220 4/27/2010 48.988 -129.843 10.0g 3.6Mw 258 4/26/2010 49.024 -129.603 10.0g 3.4Mw 243 4/26/2010 49.681 -127.069 24.4* 1.5ML 69 4/26/2010 48.711 -129.034 10.0g 3.3Mw 233 4/26/2010 49.111 -123.860 14.6* 1.3ML 8 4/26/2010 48.742 -125.330 27.2* 1.5ML 28 4/25/2010 49.241 -127.987 10.0g 2.9Mw 145 4/25/2010 48.806 -123.816 21.1* 1.1ML 8 4/25/2010 49.612 -128.424 10.0g 2.8Mw 140 4/24/2010 48.598 -123.098 9.2* 1.3ML 22 4/23/2010 49.299 -126.792 22.6* 1.4ML 65 4/23/2010 49.288 -126.824 14.6* 1.8ML 67 4/23/2010 49.280 -126.854 15.7* 1.7ML 69 4/23/2010 49.285 -126.835 15.7* 1.4ML 68 4/23/2010 49.020 -125.276 33.2* 1.1ML 21 4/23/2010 49.350 -127.918 10.0g 2.2Mw 136 4/23/2010 48.163 -123.365 35.8* 1.5ML 30 4/22/2010 48.858 -128.552 10.0g 3.1Mw 195 4/21/2010 48.753 -128.304 10.0g 3.1Mw 180 4/20/2010 49.129 -127.986 10.0g 2.8Mw 149 4/20/2010 48.873 -128.966 10.0g 3.3Mw 224 4/20/2010 50.099 -127.887 23.6* 1.5ML 74 4/20/2010 50.575 -129.429 10.0g 2.4ML 142 4/20/2010 50.561 -129.378 10.0g 2.3ML 139 4/20/2010 49.502 -126.856 32.3* 1.5ML 58 4/20/2010 49.102 -127.940 10.0g 3.2Mw 147 4/19/2010 48.613 -122.991 12.5* 0.9ML 30 4/18/2010 48.422 -122.890 29.0* 1.0ML 35 4/18/2010 48.304 -123.307 39.3* 1.2ML 14 4/18/2010 50.372 -128.829 10.0g 2.4Mw 106 4/18/2010 49.111 -127.931 10.0g 2.3Mw 146 4/18/2010 49.114 -127.915 10.0g 2.7Mw 145 4/18/2010 49.073 -127.919 10.0g 2.3Mw 146 4/18/2010 49.297 -128.310 10.0g 2.3Mw 165 4/17/2010 49.614 -126.919 23.8* 1.4ML 59 4/17/2010 48.973 -129.340 10.0g 2.6Mw 236 4/17/2010 49.724 -127.207 27.7* 0.6ML 79 4/17/2010 48.592 -123.088 16.2* 1.3ML 23 4/17/2010 49.136 -127.993 10.0g 2.3Mw 150

4/17/2010 49.161 -127.944 10.0g 2.4Mw 145 4/17/2010 48.616 -123.103 9.9* 1.0ML 22 4/17/2010 48.612 -123.101 3.4* 1.1ML 22 4/17/2010 49.039 -127.937 10.0g 2.3Mw 147 4/16/2010 49.056 -127.965 10.0g 2.5Mw 149 4/16/2010 48.602 -123.094 10.3* 1.2ML 23 4/16/2010 49.019 -128.002 10.0g 2.5Mw 152 4/16/2010 49.034 -127.973 10.0g 2.3Mw 150 4/16/2010 49.075 -127.932 10.0g 2.2Mw 147 4/16/2010 49.102 -127.992 10.0g 2.6Mw 151 4/16/2010 49.078 -127.962 10.0g 2.3Mw 149 4/16/2010 49.097 -127.977 10.0g 2.2Mw 150 4/16/2010 49.091 -127.990 10.0g 2.2Mw 151 4/16/2010 49.058 -127.953 10.0g 2.1Mw 148 4/16/2010 49.074 -127.965 10.0g 2.2Mw 149 4/16/2010 49.126 -127.978 10.0g 2.1Mw 149 4/16/2010 49.067 -127.979 10.0g 3.6Mw 150 4/16/2010 49.137 -128.000 10.0g 2.6Mw 150 4/16/2010 49.130 -127.985 10.0g 2.0Mw 149 4/16/2010 49.082 -128.038 10.0g 2.5Mw 154 4/16/2010 47.923 -124.432 36.0* 1.5ML 97 4/15/2010 49.623 -128.142 10.0g 2.5Mw 130 4/15/2010 49.593 -128.175 10.0g 2.1Mw 134 4/15/2010 48.931 -125.668 30.0* 0.9ML 8 4/14/2010 49.065 -127.968 10.0g 2.3Mw 149 4/14/2010 49.077 -127.939 10.0g 2.7Mw 147 4/14/2010 49.009 -127.984 10.0g 2.7Mw 151 4/14/2010 49.053 -127.948 10.0g 2.7Mw 148 4/14/2010 49.069 -127.925 10.0g 2.7Mw 146 4/14/2010 48.773 -123.327 19.6* 0.4ML 14 4/14/2010 49.097 -127.944 10.0g 2.4Mw 147 4/14/2010 49.051 -127.955 10.0g 2.6Mw 148 4/14/2010 49.019 -127.987 10.0g 2.7Mw 151 4/14/2010 49.019 -128.022 10.0g 2.9Mw 154 4/14/2010 49.053 -127.977 10.0g 2.7Mw 150 4/14/2010 49.066 -127.970 10.0g 3.0Mw 149 4/14/2010 49.055 -127.975 10.0g 3.0Mw 150 4/14/2010 48.835 -125.940 34.5* 1.7ML 31 4/14/2010 49.060 -127.927 10.0g 2.5Mw 146 4/14/2010 49.052 -127.947 10.0g 2.9Mw 148 4/14/2010 49.015 -127.967 10.0g 2.8Mw 150 4/14/2010 49.733 -127.953 31.2* 1.5ML 114 4/14/2010 49.103 -127.941 10.0g 2.3Mw 147 4/14/2010 49.045 -127.966 10.0g 2.4Mw 149 4/14/2010 49.046 -127.968 10.0g 2.8Mw 149 4/14/2010 49.019 -127.993 10.0g 2.6Mw 152

4/14/2010 49.459 -127.407 31.5* 1.6ML 97 4/13/2010 48.252 -122.906 18.0* 1.3ML 39 4/13/2010 48.308 -125.288 27.8* 1.6ML 74 4/13/2010 48.852 -130.158 10.0g 3.4Mw 284 4/13/2010 49.456 -127.256 19.6* 1.5ML 87 4/13/2010 49.528 -126.854 29.0* 1.4ML 57 4/13/2010 49.281 -127.913 10.0g 2.8Mw 138 4/12/2010 48.824 -128.667 10.0g 2.8Mw 204 4/12/2010 50.188 -130.196 10.0g 2.7Mw 205 4/12/2010 50.030 -130.292 10.0g 2.7Mw 217 4/12/2010 49.141 -129.890 10.0g 2.9Mw 248 4/12/2010 50.126 -130.188 10.0g 2.7Mw 206 4/12/2010 50.061 -130.265 10.0g 3.1Mw 214 4/11/2010 49.723 -128.190 29.9* 1.7ML 121 4/11/2010 50.034 -127.867 24.0* 1.3ML 80 4/9/2010 50.231 -130.141 10.0g 3.2Mw 199 4/8/2010 49.220 -128.329 10.0g 2.8Mw 169 4/8/2010 49.900 -127.920 9.4* 1.7ML 96 4/7/2010 48.718 -123.988 22.3* 1.6ML 22 4/7/2010 49.668 -127.720 20.3* 1.9ML 116 4/7/2010 49.728 -123.587 6.0* 1.0ML 30 4/5/2010 47.910 -128.344 10.0g 3.4Mw 226 4/4/2010 50.196 -127.785 20.5* 1.4ML 61 4/2/2010 50.191 -123.668 3.7* 0.0ML 50 4/1/2010 48.154 -122.885 24.0* 1.4ML 47 4/1/2010 50.849 -126.636 5.5* 1.7ML 57

3/30/2010 48.256 -125.707 43.0* 2.1ML 78 3/30/2010 49.261 -127.757 10.0g 2.8Mw 128 3/29/2010 50.118 -127.863 24.0* 1.5ML 72 3/29/2010 48.951 -125.794 27.4* 1.8ML 17 3/28/2010 49.373 -123.931 64.2* 1.3ML 16 3/27/2010 48.766 -125.337 32.1* 1.1ML 25 3/26/2010 49.801 -126.175 1.2* 0.9ML 14 3/26/2010 49.177 -129.953 10.0g 3.0Mw 248 3/26/2010 49.514 -127.229 21.1* 1.6ML 83 3/25/2010 49.500 -127.704 29.4* 1.6ML 117 3/25/2010 49.089 -125.594 16.4* 0.5ML 15 3/25/2010 48.527 -127.760 10.0g 3.2Mw 151 3/24/2010 48.559 -125.181 27.8* 1.0ML 51 3/24/2010 49.283 -128.900 10.0g 2.8Mw 190 3/24/2010 49.476 -127.303 32.4* 1.9ML 89 3/23/2010 48.871 -124.687 9.9* 1.1ML 41 3/23/2010 49.080 -129.764 10.0g 3.1Mw 246 3/23/2010 49.026 -129.743 10.0g 3.1Mw 250 3/23/2010 49.141 -126.389 31.1* 1.3ML 34 3/23/2010 50.286 -127.644 13.1* 1.3ML 48

3/22/2010 50.007 -127.812 22.4* 1.2ML 82 3/22/2010 50.000 -127.771 19.3* 1.4ML 81 3/22/2010 49.987 -127.781 18.7* 1.5ML 83 3/22/2010 49.954 -127.720 12.2* 1.5ML 85 3/22/2010 49.986 -127.769 17.6* 1.3ML 83 3/22/2010 49.983 -127.821 17.6* 1.3ML 84 3/22/2010 49.988 -127.806 19.2* 1.6ML 83 3/22/2010 49.973 -127.808 16.7* 1.4ML 85 3/21/2010 48.904 -124.661 35.5* 1.3ML 37 3/20/2010 49.996 -127.741 1.0g 1.4ML 81 3/20/2010 49.626 -127.358 30.7* 1.7ML 90 3/20/2010 48.559 -125.249 30.7* 1.5ML 48 3/20/2010 49.390 -124.527 49.2* 1.3ML 26 3/20/2010 48.807 -125.619 26.5* 0.7ML 16 3/20/2010 48.880 -125.197 36.4* 1.8ML 26 3/19/2010 50.268 -130.054 10.0g 2.4Mw 192 3/19/2010 49.705 -127.510 19.3* 1.2ML 101 3/18/2010 50.282 -126.678 0.0* 1.1ML 70 3/18/2010 49.550 -123.066 3.1* 0.6ML 18 3/18/2010 48.877 -123.573 16.1* 1.0ML 14 3/18/2010 48.872 -123.578 16.0* 0.8ML 13 3/17/2010 49.490 -128.611 10.0g 3.2Mw 159 3/17/2010 48.039 -123.107 46.1* 2.0ML 47 3/16/2010 48.790 -129.266 10.0g 3.9Mw 247 3/14/2010 48.722 -129.171 10.0g 3.8Mw 242 3/14/2010 49.080 -125.602 16.5* 1.6ML 14 3/13/2010 48.068 -125.184 40.9* 2.1ML 101 3/13/2010 48.985 -128.316 10.0g 3.2Mw 175 3/12/2010 48.790 -123.179 55.9* 1.3ML 22 3/12/2010 49.127 -125.514 34.7* 2.0ML 19 3/10/2010 50.546 -128.977 26.7* 2.2ML 111 3/9/2010 49.642 -126.762 29.7* 1.9ML 47 3/9/2010 49.234 -126.803 28.8* 1.7ML 65 3/8/2010 49.537 -127.253 23.4* 1.5ML 84 3/8/2010 49.194 -125.667 28.9* 1.5ML 18 3/8/2010 49.436 -129.532 10.0g 3.0Mw 206 3/8/2010 49.677 -123.627 0.0* 1.2ML 24 3/7/2010 49.444 -129.460 10.0g 3.5Mw 202 3/7/2010 48.633 -124.940 0.0* 1.5ML 56 3/7/2010 49.425 -128.325 10.0g 2.6Mw 156 3/7/2010 49.569 -127.285 27.3* 2.1ML 86 3/7/2010 49.243 -123.615 13.9* 1.7ML 19 3/7/2010 49.531 -127.272 19.9* 1.4ML 86 3/7/2010 49.573 -127.266 20.6* 1.3ML 84 3/6/2010 49.995 -128.304 10.6* 1.5ML 100 3/6/2010 49.718 -127.307 22.6* 1.4ML 86

3/5/2010 48.455 -123.304 20.2* 0.9ML 5 3/5/2010 49.457 -127.315 19.8* 2.2ML 91 3/4/2010 48.855 -128.897 10.0g 3.3Mw 220 3/4/2010 49.334 -123.973 61.2* 0.9ML 18 3/4/2010 49.838 -126.875 34.9* 1.6ML 58 3/4/2010 49.570 -126.905 30.3* 1.4ML 59 3/3/2010 49.489 -127.195 0.6* 1.5ML 81 3/3/2010 50.096 -127.846 22.9* 1.1ML 73 3/3/2010 49.134 -122.913 18.5* 1.3ML 19 3/3/2010 49.551 -127.296 23.9* 1.8ML 87 3/2/2010 49.038 -125.553 29.2* 1.6ML 9

2/27/2010 48.950 -122.825 15.8* 1.2ML 21 2/27/2010 50.977 -125.817 5.0g 1.7ML 112 2/26/2010 48.482 -123.394 21.1* 1.5ML 5 2/25/2010 49.764 -126.963 34.3* 1.6ML 62 2/25/2010 50.072 -128.034 13.9* 1.6ML 82 2/25/2010 49.264 -129.926 10.0g 3.4Mw 240 2/24/2010 49.884 -124.072 1.0* 1.6ML 33 2/24/2010 48.472 -123.254 21.0* 1.3ML 9 2/24/2010 47.723 -123.353 48.5* 1.8ML 77 2/24/2010 46.747 -124.045 37.3g 2.7ML 160 2/23/2010 48.796 -125.856 24.5* 1.6ML 28 2/22/2010 49.968 -128.316 20.6* 1.4ML 103 2/22/2010 49.006 -129.567 10.0g 2.6Mw 243 2/22/2010 49.368 -127.789 10.0g 2.5Mw 126 2/22/2010 48.458 -123.293 19.7* 0.9ML 6 2/21/2010 49.722 -123.579 1.7* 1.2ML 29 2/21/2010 49.638 -127.083 19.9* 1.2ML 71 2/20/2010 50.083 -127.983 18.0* 1.5ML 79 2/20/2010 48.787 -128.266 10.0g 2.2ML 176 2/20/2010 49.632 -127.074 18.0* 1.1ML 70 2/20/2010 48.322 -123.200 46.0* 3.0ML 17 2/20/2010 49.608 -126.623 36.0* 1.1ML 38 2/20/2010 49.460 -126.921 11.4* 1.1ML 64 2/20/2010 48.750 -128.324 10.0g 3.0Mw 181 2/20/2010 49.623 -127.099 21.0* 1.0ML 72 2/20/2010 48.868 -123.590 11.9* 0.2ML 12 2/20/2010 49.627 -127.092 18.7* 1.2ML 71 2/20/2010 48.718 -128.291 10.0g 2.8Mw 180 2/20/2010 48.762 -128.344 10.0g 3.1Mw 182 2/19/2010 48.794 -128.319 10.0g 2.6Mw 179 2/19/2010 49.559 -127.572 29.7* 1.3ML 107 2/19/2010 51.206 -125.794 1.0g 1.6ML 126 2/18/2010 49.084 -125.570 29.9* 2.1ML 15 2/17/2010 49.993 -127.767 18.2* 2.0ML 82 2/13/2010 47.883 -122.983 12.6* 1.6ML 58

2/10/2010 49.688 -127.018 33.5* 2.2ML 66 2/10/2010 48.399 -124.931 27.1* 0.7ML 76 2/10/2010 51.167 -126.114 6.0* 1.8ML 105 2/9/2010 48.873 -129.140 10.0g 3.0Mw 237 2/9/2010 48.427 -123.304 16.0* 1.3ML 4 2/8/2010 49.051 -128.804 10.0g 3.4Mw 208 2/8/2010 49.054 -128.029 10.0g 3.2Mw 154 2/8/2010 49.324 -129.171 10.0g 2.7Mw 197 2/7/2010 51.122 -127.616 6.6* 1.7ML 49 2/7/2010 48.877 -126.456 45.7* 1.8ML 49 2/7/2010 48.872 -123.592 14.6* 0.9ML 12 2/6/2010 48.984 -129.085 10.0g 3.3Mw 225 2/4/2010 49.481 -129.711 10.0g 2.9Mw 212 2/4/2010 48.874 -123.583 13.5* 0.7ML 13 2/4/2010 50.178 -123.906 4.3* 1.2ML 57 2/4/2010 49.323 -125.575 21.6* 1.4ML 31 2/4/2010 50.656 -128.062 12.1* 1.0ML 45 2/3/2010 48.873 -123.579 16.1* 0.6ML 13 2/3/2010 49.620 -126.930 31.4* 1.0ML 60 2/3/2010 49.494 -129.794 10.0g 3.1Mw 216 2/3/2010 49.441 -129.747 10.0g 2.9Mw 217 2/3/2010 49.476 -129.892 10.0g 3.0Mw 223 2/3/2010 48.937 -125.350 34.6* 1.2ML 14 2/3/2010 49.434 -129.841 10.0g 3.0Mw 223 2/3/2010 49.754 -128.015 34.8* 1.5ML 113 2/3/2010 49.266 -127.910 10.0g 2.8Mw 138 2/2/2010 49.325 -129.502 10.0g 3.1Mw 213 2/2/2010 49.255 -129.694 10.0g 3.1Mw 229 2/2/2010 48.656 -123.461 0.3* 1.0ML 4 2/1/2010 48.877 -123.584 13.9* 0.4ML 13 2/1/2010 48.347 -123.329 1.7* 1.2ML 10 2/1/2010 48.565 -123.078 13.4* 0.1ML 25 2/1/2010 48.346 -124.985 31.9* 1.8ML 79 2/1/2010 48.814 -128.510 10.0g 2.7Mw 193 2/1/2010 48.878 -123.584 14.6* 0.6ML 13

1/31/2010 48.962 -123.891 46.4* 1.0ML 22 1/30/2010 49.840 -124.000 2.8* 1.0ML 38 1/30/2010 50.179 -123.916 5.0g 1.3ML 57 1/29/2010 50.157 -123.885 19.4* 1.5ML 57 1/28/2010 49.474 -125.058 0.0* 0.8ML 23 1/28/2010 49.220 -127.882 10.0g 3.3Mw 138 1/27/2010 49.424 -127.225 24.8* 1.7ML 86 1/27/2010 50.120 -128.038 25.1* 1.7ML 78 1/26/2010 50.175 -127.841 22.3* 1.5ML 65 1/25/2010 50.663 -129.281 0.9* 2.4ML 131 1/25/2010 50.199 -123.913 6.0* 1.6ML 58

1/25/2010 48.683 -123.141 20.3* 1.4ML 19 1/24/2010 48.922 -129.118 10.0g 3.7Mw 232 1/24/2010 48.672 -123.141 20.5* 0.5ML 19 1/24/2010 47.757 -124.819 47.9* 2.1ML 131 1/24/2010 48.679 -123.148 20.6* 0.9ML 18 1/24/2010 48.626 -124.617 2.6* 0.8ML 68 1/23/2010 48.554 -123.351 40.8* 0.7ML 11 1/22/2010 50.412 -129.137 10.0g 2.9Mw 125 1/22/2010 48.746 -129.884 10.0g 3.3Mw 280 1/22/2010 48.468 -123.425 17.9* 1.4ML 5 1/22/2010 48.596 -123.034 17.1* 0.6ML 27 1/22/2010 48.389 -123.361 20.3* 1.2ML 4 1/22/2010 48.605 -123.059 13.8* 1.3ML 25 1/22/2010 50.699 -128.081 15.8* 1.6ML 46 1/20/2010 48.856 -129.407 10.0g 3.5Mw 250 1/20/2010 48.923 -129.416 10.0g 3.6Mw 244 1/20/2010 49.365 -127.010 24.6* 1.7ML 74 1/19/2010 49.139 -127.988 10.0g 2.8Mw 149 1/18/2010 48.082 -128.182 10.0g 3.6Mw 204 1/18/2010 49.625 -126.894 27.8* 2.0ML 57 1/17/2010 49.109 -123.863 16.6* 1.0ML 8 1/16/2010 49.109 -123.860 16.1* 1.1ML 8 1/15/2010 49.991 -127.872 31.8* 1.7ML 85 1/15/2010 49.724 -127.036 25.8* 2.3ML 67 1/14/2010 49.139 -128.002 10.0g 2.5Mw 150 1/14/2010 49.024 -125.254 35.1* 1.4ML 23 1/13/2010 48.661 -128.880 10.0g 3.5Mw 223 1/12/2010 48.670 -128.890 10.0g 4.4Mw 223 1/10/2010 50.189 -127.775 19.4* 1.6ML 62 1/9/2010 49.561 -127.199 25.4* 1.7ML 80 1/9/2010 49.317 -123.953 63.2* 1.4ML 16 1/8/2010 48.012 -124.603 40.3* 1.6ML 102 1/8/2010 48.008 -124.649 42.0* 2.1ML 106 1/8/2010 48.997 -129.159 10.0g 3.6Mw 227 1/7/2010 49.020 -128.978 10.0g 3.3Mw 218 1/7/2010 48.015 -124.590 39.5* 1.8ML 101 1/7/2010 48.021 -124.630 39.3* 1.7ML 104 1/7/2010 48.017 -124.624 40.2* 1.7ML 104 1/7/2010 48.015 -124.617 41.3* 1.7ML 103 1/7/2010 48.018 -124.608 39.4* 1.5ML 102 1/7/2010 50.003 -127.778 0.4* 1.6ML 81 1/7/2010 49.603 -127.299 18.9* 1.8ML 86 1/6/2010 48.978 -125.417 15.4* 1.3ML 10 1/5/2010 48.987 -128.939 10.0g 3.1Mw 219 1/5/2010 49.103 -124.180 17.3* 1.1ML 19 1/4/2010 48.867 -129.468 10.0g 3.3Mw 251

1/4/2010 50.181 -129.744 10.0g 2.7Mw 174 1/3/2010 48.904 -129.323 10.0g 3.3Mw 242 1/2/2010 49.450 -127.522 10.0g 3.0Mw 105 1/1/2010 50.050 -128.093 18.6* 2.0ML 86 1/1/2010 48.474 -123.066 23.9* 1.5ML 22 1/1/2010 47.981 -122.936 21.7* 1.7ML 59 1/1/2010 49.501 -127.222 11.6* 1.6ML 83

12/31/2009 48.852 -129.264 10.0g 3.5Mw 244 12/30/2009 48.832 -123.349 18.5* 1.3ML 20 12/29/2009 48.927 -123.532 49.9* 0.9ML 20 12/29/2009 49.495 -128.302 10.0g 2.7Mw 148 12/28/2009 50.092 -127.914 24.5* 1.5ML 76 12/28/2009 48.617 -123.109 3.2* 0.7ML 21 12/27/2009 48.765 -123.250 21.0* 1.0ML 16 12/27/2009 50.052 -127.967 18.8* 1.7ML 82 12/27/2009 50.198 -123.969 5.0g 1.7ML 55 12/25/2009 49.071 -125.609 18.9* 1.7ML 14 12/25/2009 48.053 -128.241 10.0g 2.8ML 210 12/25/2009 49.009 -125.406 34.2* 1.6ML 12 12/23/2009 48.205 -123.106 19.2* 1.4ML 31 12/23/2009 48.501 -123.394 25.6* 1.3ML 7 12/23/2009 49.026 -128.598 10.0g 2.7Mw 195 12/23/2009 49.483 -127.242 26.9* 1.7ML 85 12/23/2009 49.520 -127.152 28.2* 1.3ML 78 12/23/2009 48.993 -128.329 10.0g 2.6Mw 176 12/22/2009 49.542 -126.976 29.2* 1.4ML 65 12/22/2009 49.016 -123.533 10.6* 1.0ML 28 12/22/2009 50.200 -127.835 15.9* 1.5ML 63 12/22/2009 50.132 -127.826 25.5* 1.1ML 69 12/21/2009 50.219 -127.707 22.4* 1.3ML 57 12/21/2009 49.688 -127.317 21.6* 2.6ML 87 12/20/2009 48.922 -125.871 35.1* 2.6ML 23 12/18/2009 47.621 -123.336 47.1* 2.0ML 75 12/18/2009 48.312 -124.857 0.0* 1.9ML 87 12/17/2009 48.286 -124.877 0.0* 1.7ML 88 12/16/2009 49.461 -127.912 9.5* 2.7Mw 133 12/15/2009 49.513 -127.212 28.5* 1.9ML 82 12/15/2009 48.848 -129.090 10.0g 3.4Mw 234 12/15/2009 49.449 -127.834 10.0g 3.2Mw 127 12/15/2009 49.431 -127.847 10.0g 2.8Mw 129 12/14/2009 47.389 -129.130 10.0g 3.6Mw 308 12/13/2009 49.403 -130.097 10.0g 2.7Mw 239 12/13/2009 49.392 -130.059 10.0g 2.8Mw 238 12/13/2009 49.385 -130.076 10.0g 2.8Mw 239 12/13/2009 49.401 -130.128 10.0g 2.9Mw 241 12/13/2009 49.461 -130.102 10.0g 3.0Mw 236

12/13/2009 49.088 -128.633 10.0g 2.4Mw 195 12/13/2009 48.912 -129.302 10.0g 2.4Mw 240 12/11/2009 48.462 -123.295 19.9* 0.5ML 6 12/11/2009 48.963 -129.138 10.0g 2.7Mw 229 12/11/2009 49.709 -126.316 3.3* 0.7ML 15 12/11/2009 49.994 -127.772 12.2* 1.0ML 82 12/11/2009 49.994 -127.775 12.5* 0.9ML 82 12/11/2009 48.892 -128.971 10.0g 2.7Mw 224 12/10/2009 49.523 -127.131 9.8* 1.0ML 76 12/10/2009 50.211 -127.793 19.1* 1.0ML 60 12/10/2009 49.337 -128.985 10.0g 2.6Mw 188 12/9/2009 49.079 -125.596 15.7* 0.9ML 14 12/9/2009 49.534 -127.215 30.0* 1.6ML 82 12/9/2009 49.246 -130.070 10.0g 3.0Mw 249 12/8/2009 48.983 -125.427 13.4* 1.3ML 9 12/8/2009 48.824 -128.747 10.0g 3.4Mw 209 12/8/2009 49.475 -127.260 30.5* 1.5ML 86 12/8/2009 49.034 -129.217 10.0g 2.8Mw 225 12/7/2009 49.003 -129.301 10.0g 2.9Mw 232 12/4/2009 48.650 -123.029 19.0* 1.1ML 27 12/4/2009 50.215 -127.700 23.2* 1.2ML 57 12/3/2009 49.553 -127.019 11.3* 1.5ML 67 12/3/2009 49.311 -129.384 10.0g 3.0Mw 209 12/3/2009 49.999 -127.737 21.2* 2.3ML 81 12/2/2009 49.240 -123.614 8.9* 0.8ML 19 12/2/2009 49.394 -127.798 10.0g 2.2Mw 126 12/2/2009 49.312 -123.935 62.4* 1.1ML 16 12/1/2009 49.313 -123.944 60.6* 1.1ML 16

11/30/2009 49.577 -126.872 30.0* 1.8ML 56 11/30/2009 48.749 -124.734 35.1* 1.2ML 54 11/30/2009 49.461 -127.240 22.4* 1.6ML 85 11/30/2009 49.481 -126.839 20.9* 1.6ML 57 11/28/2009 49.079 -125.607 19.5* 2.1ML 14 11/28/2009 49.063 -129.868 10.0g 3.5Mw 253 11/28/2009 50.610 -127.725 0.0* 1.5ML 23 11/26/2009 49.062 -127.605 10.0g 3.2Mw 123 11/26/2009 49.541 -126.798 16.4* 1.6ML 52 11/25/2009 49.102 -127.942 10.0g 3.1Mw 147 11/25/2009 48.606 -123.095 15.6* 0.7ML 22 11/25/2009 49.692 -127.230 33.7* 1.9ML 81 11/24/2009 49.270 -129.522 10.0g 3.3Mw 219 11/24/2009 49.215 -127.922 10.0g 3.2Mw 141 11/22/2009 50.190 -127.840 23.1* 1.3ML 64 11/22/2009 49.560 -127.211 24.8* 2.3ML 81 11/21/2009 49.126 -128.032 10.0g 2.8Mw 153 11/20/2009 49.834 -127.758 32.5* 2.7ML 99

11/17/2009 49.328 -128.233 10.0g 2.8Mw 159 11/17/2009 49.731 -126.983 33.0* 1.8ML 63 11/16/2009 49.600 -127.272 3.5* 2.0ML 84 11/13/2009 49.595 -127.260 23.0* 2.1ML 84 11/12/2009 48.592 -123.537 25.5* 0.9ML 11 11/12/2009 49.108 -126.808 38.6* 1.6ML 65 11/12/2009 48.173 -124.654 36.4* 1.8ML 97 11/11/2009 49.855 -124.421 0.0* 1.3ML 8 11/11/2009 48.832 -128.898 10.0g 3.5Mw 220 11/11/2009 49.064 -129.223 10.0g 3.3Mw 223 11/11/2009 48.914 -128.738 10.0g 3.2Mw 207 11/11/2009 49.517 -127.813 33.3* 1.9ML 124 11/10/2009 49.256 -129.315 10.0g 3.2Mw 210 11/10/2009 48.941 -129.013 10.0g 3.2Mw 226 11/9/2009 50.649 -126.187 1.0* 1.6ML 86 11/7/2009 50.285 -130.042 10.0g 2.7ML 191 11/6/2009 49.520 -127.278 22.4* 1.9ML 86 11/6/2009 50.088 -125.985 18.9* 1.5ML 45 11/5/2009 49.678 -127.153 18.7* 2.2ML 75 11/5/2009 50.214 -129.985 10.0g 3.3Mw 189 11/5/2009 50.869 -124.553 45.3* 1.8ML 109 11/4/2009 49.527 -127.198 26.2* 1.3ML 81 11/3/2009 50.188 -129.673 10.0g 2.7Mw 169 11/2/2009 50.439 -124.297 6.1* 2.3ML 67 11/1/2009 49.036 -128.380 10.0g 3.0Mw 179

10/31/2009 50.073 -130.268 10.0g 4.1Mw 214 10/31/2009 49.849 -127.525 22.8* 1.7ML 95 10/30/2009 49.066 -128.248 10.0g 3.2Mw 170 10/30/2009 49.092 -128.335 10.0g 3.1Mw 174 10/28/2009 48.800 -129.119 10.0g 3.4Mw 237 10/28/2009 50.057 -130.119 10.0g 2.9Mw 204 10/27/2009 48.474 -122.869 30.0* 1.5ML 37 10/27/2009 48.951 -125.175 38.6* 1.3ML 27 10/27/2009 48.406 -124.935 25.5* 1.9ML 75 10/26/2009 48.420 -124.936 28.8* 2.0ML 74 10/26/2009 49.746 -127.118 28.4* 1.8ML 73 10/25/2009 48.462 -125.047 37.4* 1.4ML 65 10/24/2009 48.755 -128.974 10.0g 3.2Mw 227 10/24/2009 48.441 -125.341 17.6* 1.7ML 58 10/24/2009 49.071 -128.825 10.0g 2.7Mw 207 10/24/2009 49.134 -125.369 0.0* 1.7ML 24 10/23/2009 49.249 -127.953 10.0g 3.1Mw 142 10/23/2009 48.801 -128.794 10.0g 3.4Mw 213 10/22/2009 49.124 -128.038 10.0g 3.0Mw 153 10/22/2009 48.734 -129.046 10.0g 3.4Mw 233 10/22/2009 49.267 -127.886 10.0g 3.0Mw 137

10/22/2009 50.194 -127.763 19.4* 1.0ML 61 10/22/2009 49.428 -127.755 10.0g 2.8Mw 122 10/21/2009 49.082 -125.610 16.2* 1.5ML 15 10/21/2009 47.427 -128.842 10.0g 3.6Mw 289 10/19/2009 49.971 -130.027 10.0g 2.5Mw 202 10/19/2009 49.985 -130.068 10.0g 2.6Mw 204 10/19/2009 49.664 -127.166 21.3* 1.0ML 76 10/19/2009 49.549 -126.764 26.0* 1.1ML 50 10/19/2009 48.836 -127.966 10.0g 2.2Mw 153 10/19/2009 48.403 -123.997 49.9* 1.7ML 46 10/18/2009 49.717 -127.181 33.0* 1.6ML 77 10/18/2009 48.512 -123.673 15.8* 1.0ML 24 10/17/2009 48.163 -124.918 19.1* 1.8ML 99 10/17/2009 48.819 -129.768 10.0g 3.4Mw 269 10/16/2009 50.064 -127.983 21.9* 3.2ML 81 10/16/2009 47.543 -129.127 10.0g 4.0Mw 297 10/16/2009 48.797 -128.857 10.0g 3.3Mw 218 10/16/2009 47.986 -128.233 10.0g 3.4Mw 214 10/15/2009 50.202 -127.753 1.5* 1.7ML 60 10/15/2009 49.364 -127.621 10.0g 4.0Mw 115 10/12/2009 49.851 -127.606 23.8* 1.2ML 95 10/12/2009 50.055 -128.111 23.0* 1.3ML 87 10/11/2009 49.477 -127.692 43.9* 1.4ML 117 10/11/2009 49.063 -127.767 10.0g 2.3Mw 135 10/11/2009 49.700 -123.313 10.7* 0.6ML 10 10/11/2009 49.248 -127.985 10.0g 2.0Mw 144 10/11/2009 49.280 -128.882 10.0g 2.1Mw 189 10/11/2009 49.497 -129.522 10.0g 2.8Mw 201 10/10/2009 48.958 -128.195 10.0g 2.5Mw 167 10/9/2009 49.495 -129.303 10.0g 2.6Mw 190 10/9/2009 48.212 -124.664 4.4* 1.3ML 95 10/9/2009 49.495 -127.790 38.1* 1.7ML 123 10/9/2009 49.478 -129.455 10.0g 3.2Mw 199 10/8/2009 48.958 -130.262 10.0g 3.3Mw 281 10/8/2009 50.189 -127.794 22.4* 0.9ML 62 10/8/2009 48.886 -129.018 10.0g 2.7Mw 228 10/8/2009 50.268 -127.758 19.7* 0.9ML 53 10/7/2009 49.269 -127.905 10.0g 2.5Mw 138 10/6/2009 48.588 -125.258 28.9* 0.6ML 45 10/6/2009 48.867 -125.869 26.6* 0.9ML 25 10/6/2009 50.045 -127.992 24.3* 1.3ML 83 10/6/2009 50.053 -127.982 22.4* 1.2ML 82 10/6/2009 50.061 -127.977 24.1* 1.2ML 81 10/6/2009 49.237 -123.625 17.8* 0.5ML 20 10/6/2009 48.213 -123.138 46.4* 0.8ML 29 10/5/2009 48.643 -125.317 28.8* 1.0ML 38

10/5/2009 48.773 -125.605 27.0* 0.2ML 20 10/4/2009 49.633 -127.717 22.7* 1.3ML 116 10/3/2009 49.301 -126.039 0.0* 1.3ML 18 10/3/2009 48.651 -125.040 32.0* 1.2ML 50 10/3/2009 48.602 -128.616 10.0g 2.8Mw 206 10/2/2009 48.392 -125.349 22.9* 1.7ML 63 10/2/2009 49.387 -129.350 10.0g 3.0Mw 201 10/2/2009 49.321 -127.621 10.0g 2.6Mw 117 10/2/2009 50.086 -127.961 28.6* 1.1ML 78 10/2/2009 48.739 -123.968 27.4* 1.1ML 20 10/2/2009 49.013 -128.973 10.0g 3.1Mw 218 10/1/2009 48.019 -128.273 10.0g 3.3Mw 214 10/1/2009 48.842 -128.825 10.0g 3.2Mw 215 10/1/2009 49.157 -127.980 10.0g 2.7Mw 148 10/1/2009 49.466 -124.944 0.0* 1.1ML 24 10/1/2009 50.371 -123.772 1.0g 1.5ML 63 10/1/2009 50.401 -123.792 1.0g 1.7ML 66 10/1/2009 48.589 -125.414 29.0* 1.5ML 41 9/29/2009 48.872 -129.108 10.0g 3.1Mw 235 9/29/2009 49.526 -127.222 26.5* 1.4ML 82 9/29/2009 49.150 -128.037 10.0g 2.6Mw 152 9/28/2009 49.305 -126.003 1.0g 1.3ML 18 9/28/2009 49.728 -128.501 10.0g 2.5Mw 132 9/28/2009 49.838 -123.640 3.2* 1.0ML 37 9/27/2009 48.772 -125.202 17.1* 1.5ML 32 9/27/2009 49.542 -126.621 18.4* 1.2ML 40 9/27/2009 49.685 -127.453 2.5* 1.4ML 97 9/27/2009 49.654 -127.453 19.2* 1.4ML 97 9/26/2009 49.111 -128.029 10.0g 3.9Mw 153 9/26/2009 49.020 -128.588 10.0g 2.9Mw 194 9/26/2009 48.231 -122.885 52.4* 1.2ML 42 9/26/2009 49.627 -126.941 31.7* 1.4ML 60 9/26/2009 49.478 -127.268 31.4* 1.7ML 87 9/26/2009 49.620 -126.955 41.4* 1.5ML 62 9/26/2009 50.129 -127.843 26.2* 1.4ML 70 9/25/2009 48.330 -123.166 26.1* 0.6ML 18 9/25/2009 48.940 -129.475 10.0g 2.9Mw 245 9/25/2009 48.945 -128.864 10.0g 2.8Mw 216 9/25/2009 48.963 -129.216 10.0g 2.4ML 232 9/24/2009 50.056 -128.342 24.7* 1.3ML 97 9/23/2009 50.132 -125.839 19.0* 0.9ML 38 9/22/2009 48.111 -128.175 10.0g 3.0Mw 202 9/22/2009 50.188 -127.804 21.5* 1.0ML 63 9/21/2009 49.066 -125.950 32.2* 1.5ML 9 9/21/2009 48.402 -123.996 48.6* 1.1ML 46 9/20/2009 48.807 -128.146 10.0g 3.0Mw 167

9/20/2009 49.480 -127.849 10.0g 2.3Mw 128 9/20/2009 49.073 -125.567 15.7* 0.7ML 13 9/20/2009 47.958 -128.303 10.0g 3.2Mw 220 9/19/2009 49.758 -127.062 32.3* 1.3ML 69 9/18/2009 49.384 -124.038 64.6* 1.5ML 22 9/18/2009 48.048 -128.173 10.0g 3.4Mw 206 9/18/2009 48.834 -129.385 10.0g 3.5Mw 251 9/18/2009 49.459 -128.043 10.0g 2.9Mw 142 9/18/2009 48.421 -123.197 23.4* 1.4ML 12 9/17/2009 48.902 -129.411 10.0g 3.2Mw 246 9/17/2009 48.658 -123.061 18.0* 0.9ML 24 9/16/2009 48.730 -122.955 65.3* 1.0ML 32 9/16/2009 47.998 -128.153 10.0g 3.0Mw 208 9/15/2009 49.419 -127.008 25.0* 1.4ML 71 9/15/2009 49.114 -129.208 10.0g 3.1Mw 218 9/15/2009 47.993 -128.251 10.0g 2.9Mw 214 9/14/2009 49.878 -123.957 0.0* 1.2ML 41 9/14/2009 49.037 -126.671 35.6* 1.6ML 56 9/14/2009 48.616 -124.995 13.6* 1.3ML 55 9/14/2009 48.871 -129.481 10.0g 2.9Mw 251 9/14/2009 50.232 -130.086 10.0g 2.7Mw 196 9/14/2009 48.904 -129.092 10.0g 2.9Mw 233 9/14/2009 48.812 -129.142 10.0g 2.6Mw 238 9/14/2009 48.167 -122.860 24.5* 0.9ML 47 9/13/2009 49.357 -127.735 10.0g 2.7Mw 123 9/13/2009 50.085 -127.810 25.9* 1.0ML 73 9/13/2009 49.453 -127.241 23.2* 1.3ML 86 9/12/2009 49.358 -127.907 10.0g 2.5Mw 135 9/12/2009 49.329 -127.893 10.0g 2.5Mw 135 9/12/2009 48.179 -122.876 26.0* 1.2ML 46 9/11/2009 49.388 -123.190 15.1* 0.6ML 16 9/11/2009 50.300 -123.599 1.0g 1.1ML 49 9/10/2009 47.993 -128.289 10.0g 3.1Mw 217 9/10/2009 48.144 -124.579 0.0* 1.5ML 95 9/10/2009 49.393 -123.214 14.3* 0.8ML 17 9/8/2009 49.871 -124.297 0.0* 1.1ML 17 9/8/2009 48.290 -123.366 44.7* 1.1ML 15 9/8/2009 49.658 -126.850 26.4* 1.7ML 54 9/7/2009 49.692 -123.788 13.4* 1.2ML 25 9/7/2009 48.071 -128.193 10.0g 3.3Mw 206 9/7/2009 49.140 -129.096 10.0g 2.8Mw 211 9/6/2009 48.911 -129.138 10.0g 3.8Mw 234 9/5/2009 48.644 -123.021 17.3* 0.9ML 27 9/5/2009 48.266 -123.223 39.1* 1.4ML 21 9/4/2009 48.624 -125.000 17.7* 1.3ML 54 9/4/2009 49.714 -123.580 1.2* 0.8ML 29

9/3/2009 48.437 -123.321 46.1* 0.8ML 3 9/3/2009 48.006 -128.129 10.0g 2.7Mw 206 9/2/2009 48.635 -125.176 27.5* 1.2ML 44 9/2/2009 49.097 -128.523 10.0g 2.6Mw 187 9/1/2009 48.673 -123.285 19.0* 0.6ML 8 9/1/2009 49.493 -127.271 30.7* 1.4ML 87

8/29/2009 49.673 -127.118 19.8* 1.5ML 73 8/29/2009 50.024 -128.371 1.0g 1.6ML 101 8/29/2009 49.220 -125.901 21.5* 1.4ML 7 8/28/2009 48.652 -123.229 17.0* 0.7ML 12 8/27/2009 48.915 -128.932 10.0g 3.3Mw 221 8/27/2009 49.812 -123.490 1.0* 0.6ML 26 8/27/2009 47.666 -123.650 29.5g 1.4ML 87 8/27/2009 48.751 -128.534 10.0g 3.1Mw 196 8/26/2009 49.975 -127.802 4.9* 1.2ML 85 8/26/2009 48.936 -129.379 10.0g 3.2Mw 241 8/26/2009 49.081 -128.103 10.0g 2.7Mw 159 8/26/2009 48.908 -129.321 10.0g 3.2Mw 241 8/26/2009 48.925 -129.425 10.0g 3.4Mw 244 8/25/2009 49.083 -125.584 15.6* 0.6ML 14 8/25/2009 49.949 -127.726 6.0* 1.3ML 86 8/24/2009 49.424 -127.045 26.2* 1.6ML 74 8/24/2009 49.415 -127.067 26.3* 1.4ML 75 8/24/2009 49.630 -127.068 15.4* 1.1ML 69 8/23/2009 50.172 -127.755 18.2* 0.9ML 63 8/23/2009 49.557 -129.532 10.0g 2.9Mw 197 8/23/2009 50.013 -126.011 19.7* 0.7ML 37 8/23/2009 50.139 -127.910 24.1* 1.0ML 71 8/23/2009 49.493 -127.165 29.7* 1.6ML 79 8/23/2009 49.080 -125.599 16.8* 1.2ML 14 8/23/2009 49.078 -125.599 18.4* 1.5ML 14 8/22/2009 50.845 -125.706 5.8* 1.2ML 95 8/20/2009 49.120 -127.882 10.0g 2.9Mw 143 8/20/2009 49.035 -125.887 20.7* 1.1ML 12 8/20/2009 48.809 -125.160 14.4* 0.7ML 32 8/19/2009 50.647 -124.339 0.0* 1.3ML 89 8/19/2009 49.658 -127.369 19.0* 1.2ML 91 8/19/2009 47.978 -128.167 10.0g 3.1Mw 210 8/19/2009 48.600 -123.722 20.3* 0.8ML 20 8/19/2009 49.350 -126.586 27.0* 1.2ML 51 8/19/2009 49.160 -125.381 34.0* 1.0ML 26 8/18/2009 47.763 -124.760 41.3* 1.5ML 127 8/18/2009 49.944 -127.976 36.8* 0.9ML 93 8/17/2009 50.000 -127.767 15.3* 1.0ML 81 8/17/2009 49.987 -127.777 10.2* 1.0ML 83 8/17/2009 50.321 -125.604 6.0* 1.1ML 38

8/17/2009 49.480 -127.245 30.7* 1.3ML 85 8/17/2009 50.080 -127.898 22.9* 1.0ML 77 8/17/2009 48.896 -129.348 10.0g 2.7Mw 244 8/17/2009 50.117 -127.879 21.0* 1.0ML 72 8/16/2009 48.910 -123.058 21.4* 0.8ML 11 8/16/2009 50.090 -127.945 13.6* 0.9ML 77 8/16/2009 48.364 -122.857 30.0* 1.2ML 38 8/16/2009 50.044 -128.028 18.6* 0.9ML 84 8/16/2009 50.025 -128.023 14.4* 1.1ML 86 8/16/2009 49.325 -126.781 42.1* 1.2ML 63 8/16/2009 49.320 -126.743 28.9* 1.1ML 61 8/14/2009 50.065 -130.092 10.0g 3.0Mw 202 8/14/2009 50.120 -130.185 10.0g 2.7ML 197 8/14/2009 50.095 -130.187 10.0g 3.4Mw 207 8/14/2009 50.075 -130.103 10.0g 2.8Mw 202 8/14/2009 50.070 -130.114 10.0g 2.6Mw 203 8/14/2009 50.050 -130.158 10.0g 3.2Mw 207 8/14/2009 50.102 -130.144 10.0g 2.8Mw 204 8/14/2009 48.638 -123.138 17.3* 0.6ML 19 8/14/2009 48.637 -123.132 18.6* 0.4ML 19 8/14/2009 50.138 -130.122 10.0g 2.6Mw 201 8/14/2009 50.081 -130.139 10.0g 2.7Mw 205 8/14/2009 48.218 -124.910 0.0* 1.4ML 94 8/13/2009 49.332 -128.324 10.0g 2.5Mw 165 8/13/2009 48.574 -123.003 59.0* 0.7ML 30 8/13/2009 49.276 -127.924 10.0g 2.3Mw 139 8/12/2009 50.311 -125.376 0.0* 0.8ML 32 8/12/2009 50.001 -127.746 4.5* 0.7ML 81 8/12/2009 48.408 -125.128 24.3* 1.2ML 67 8/12/2009 49.139 -129.304 10.0g 2.5Mw 220 8/12/2009 48.943 -126.110 37.5* 1.1ML 26 8/12/2009 48.190 -123.235 22.2* 0.8ML 28 8/12/2009 50.489 -129.023 10.0g 2.0Mw 115 8/12/2009 49.997 -127.785 26.2* 1.0ML 82 8/12/2009 49.994 -127.792 29.1* 1.0ML 82 8/11/2009 49.289 -127.874 10.0g 2.6Mw 135 8/11/2009 49.726 -123.588 4.2* 0.8ML 30 8/10/2009 49.147 -127.988 10.0g 2.5Mw 149 8/10/2009 48.599 -123.654 19.2* 0.7ML 19 8/10/2009 49.660 -127.321 18.3* 1.5ML 88 8/10/2009 48.737 -125.696 28.1* 0.9ML 26 8/9/2009 48.777 -128.978 10.0g 2.8Mw 227 8/9/2009 49.534 -127.251 25.9* 1.2ML 84 8/9/2009 48.021 -124.537 0.0* 1.4ML 98 8/9/2009 49.620 -127.388 21.1* 1.3ML 93 8/7/2009 49.473 -127.249 30.7* 1.0ML 86

8/7/2009 49.521 -127.251 2.7* 1.1ML 84 8/6/2009 47.964 -123.010 0.0* 1.0ML 58 8/6/2009 49.086 -128.003 10.0g 2.1Mw 152 8/6/2009 49.416 -127.723 10.0g 1.8Mw 120 8/6/2009 50.197 -127.700 22.6* 0.8ML 59 8/6/2009 47.521 -123.394 43.9* 1.4ML 80 8/6/2009 49.144 -128.797 10.0g 2.3Mw 199 8/5/2009 48.359 -125.047 32.0* 0.8ML 75 8/5/2009 49.906 -127.900 31.6* 2.5ML 94 8/5/2009 49.940 -127.888 29.6* 1.2ML 90 8/5/2009 49.935 -127.891 33.6* 2.7ML 91 8/5/2009 48.859 -128.932 10.0g 3.0Mw 222 8/5/2009 48.755 -129.069 10.0g 2.7Mw 234 8/4/2009 49.992 -127.858 0.0* 1.1ML 84 8/4/2009 48.864 -128.986 10.0g 3.0Mw 226 8/3/2009 48.864 -128.962 10.0g 2.9Mw 224 8/2/2009 49.580 -127.251 28.9* 1.5ML 83 8/2/2009 49.741 -127.420 15.1* 1.4ML 95 8/2/2009 49.531 -127.151 31.4* 1.7ML 77