Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
Data Series 467
U.S. Department of the Interior U.S. Geological Survey
Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
By James P. Dixon, U.S. Geological Survey, and Scott D. Stihler, University of Alaska Fairbanks
Data Series 467
U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director
U.S. Geological Survey, Reston, Virginia: 2009
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Suggested citation: Dixon, J.P., and Stihler, S.D., 2009, Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2008: U.S. Geological Survey Data Series 467, 86 p. iii
Contents
Abstract ...... 1 Introduction...... 1 Instrumentation...... 2 Data Acquisition and Processing...... 6 Seismic Velocity Models...... 6 Seismicity...... 7 Summary...... 10 Acknowledgments...... 10 References Cited...... 10 Appendix A. Maps of Monitored Volcanoes with Earthquake Hypocenters Calculated in 2008....13 Appendix B. Parameters for Alaska Volcano Observatory Seismograph Stations in 2008...... 45 Appendix C. Locations of the Alaska Volcano Observatory Seismograph Stations in 2008...... 53 Appendix D. Operational Status for Alaska Volcano Observatory Stations in 2008...... 69 Appendix E. Seismic Velocity Models Used in Locating the Earthquakes in 2008...... 75 Appendix F. Location of Volcanic Zones Modeled Using Multiple Cylinders...... 81 Appendix G. Previous Alaska Volcano Observatory Earthquake Catalogs...... 83 Appendix H. Selected Papers Published in 2008 Using Alaska Volcano Observatory Data ...... 85
Figures
Figure 1. Map showing location of volcanoes mentioned in this report… …………………… 2 Figure 2. Log-log plot of representative displacement response curves for the short-period stations using a Mark Products L4 or L4-3D seismometer… ………… 3 Figure 3. Log-log plot of representative displacement response curves for the short-period stations using a Mark Products L22 seismometer… ………………… 4 Figure 4. Log-log plot of representative displacement response curves for the short-period stations using a Teledyne-Geotech S13 seismometer… ……………… 4 Figure 5. Log-log plot of representative displacement response curves for the broadband stations using a Guralp CMG-40T seismometer… ……………………… 5 Figure 6. Log-log plot of representative displacement response curves for the broadband stations using a Guralp CMG-6TD seismometer………………………… 5 Figure 7. Map showing earthquakes located by AEIC associated with the Kasatochi eruption… 9
Figure 8. Map showing the May 2, 2008 Mw=6.6 earthquake with aftershocks and triggered seismicity located by AEIC………………………………………………… 9 iv
Tables
Table 1. Number of earthquakes located per year in the Alaska Volcano Observatory catalog… ……………………………………………………………… 1 Table 2. Number of Alaska Volcano Observatory seismograph stations by type and year……………………………………………………………………………… 3 Table 3. Volcano subnetwork designators… ………………………………………………… 7 Table 4. Alaska Volcano Observatory event description codes… …………………………… 7 Table 5. Number of earthquakes located for each seismograph subnetwork in 2007 and 2008 within 20 km of the volcanic centers in each subnetwork…………… 8
Conversion Factors and Datum
Conversion Factors
Multiply By To obtain kilometer (km) 0.6214 mile (mi) meter (m) 3.281 foot (ft)
Datum Horizontal coordinate information is referenced to North American Datum of 1927 (NAD 27). Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
By James P. Dixon1 and Scott D. Stihler2
Abstract magnitudes, phase arrival times, location quality statistics, daily station usage statistics, and all HYPOELLIPSE (Lahr, 1999) files used to determine the earthquake locations in 2008 Between January 1 and December 31, 2008, the Alaska are included in a data supplement to this report. Volcano Observatory (AVO) located 7,097 earthquakes In 2008, the AVO located 7,097 earthquakes (table 1, of which 5,318 occurred within 20 kilometers of the 33 appendix A) and of these, 5,318 were located within 20 km volcanoes monitored by the AVO. Monitoring highlights in of the 33 volcanic centers monitored (fig. 1). Two volcanoes, 2008 include the eruptions of Okmok Caldera, and Kasatochi Little Sitkin Volcano and Mount Cerberus, the active vent on Volcano, as well as increased unrest at Mount Veniaminof and Semisopochnoi Island, have not been formally added to the Redoubt Volcano. This catalog includes descriptions of: (1) list of permanently monitored volcanoes in the AVO weekly locations of seismic instrumentation deployed during 2008; update. To be included in the list of monitored volcanoes (2) earthquake detection, recording, analysis, and data archival in the AVO weekly update, the seismic subnetwork on the systems; (3) seismic velocity models used for earthquake volcano must be in place long enough so that the background locations; (4) a summary of earthquakes located in 2008; seismicity is known, typically 6 months, and have no and (5) an accompanying UNIX tar-file with a summary of prolonged station outages that prevent AVO from locating earthquake origin times, hypocenters, magnitudes, phase earthquakes. Loss of data due to telemetry failures since their arrival times, location quality statistics, daily station usage installation has prevented Little Sitkin and Mount Cerberus statistics, and all files used to determine the earthquake from being added to list of permanently monitored volcanoes. locations in 2008.
Table 1. Number of earthquakes located per year in the Alaska Introduction Volcano Observatory catalog.
The Alaska Volcano Observatory (AVO), a cooperative Number of Volcanoes monitored program of the U.S. Geological Survey, the Geophysical Year earthquakes located by the AVO Institute at the University of Alaska Fairbanks, and the Alaska per year seismograph network Division of Geological and Geophysical Surveys, has installed 1989 911 4 and maintained seismic monitoring networks at historically 1990 3,285 4 active volcanoes in Alaska since AVO inception in 1988 1991 1,119 4 1992 2,184 4 (fig. 1). The primary objectives of the AVO seismic program 1993 697 4 are the real-time seismic monitoring of active, potentially 1994 441 4 hazardous, Alaskan volcanoes and the investigation of seismic 1995 850 4 processes associated with active volcanism. This catalog 1996 6,466 14 describes the location of seismic instrumentation deployed in 1997 2,930 17 the field, the earthquake detection, recording, analysis, and 1998 2,873 20 1999 2,769 22 data archival systems, the seismic velocity models used for 2000 1,551 22 earthquake locations, and a summary of earthquakes located 2001 1,427 23 in 2008. A summary of earthquake origin times, hypocenters, 2002 7,242 24 2003 3,911 27 2004 6,928 30
1 2005 9,012 32 U.S. Geological Survey - Alaska Science Center, 903 Koyukuk Drive, 2006 8,666 33 Fairbanks, AK 99775-7320 2007 6,664 33 2University of Alaska Fairbanks - Geophysical Institute, 903 Koyukuk 2008 7,097 33 Drive, Fairbanks, AK 99775-7320 2 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
U
Canada 64 N n i
t 2008 Fairbanks ed
St
Volcano monitored by real-time seismic network a and listed in the AVO weekly update. tes ALASKA Sourdough Volcano monitored by real-time seismic network Tolsona 1 and not yet added to the list in the AVO weekly Anchorage update. 60 N 2 3 8 Kenai 7 4 Volcano unmonitored by real-time seismic network Homer and listed in the AVO weekly update. 10 5 146 W 138 W King Salmon 6 15 12 9 56 N Port Heiden 11 King Cove 13 150 W 35 Cold Bay 16 14 GULF OF ALASKA 52 N 34 Aleutian Islands Akutan
33 20 32 31 29 BERING SEA 25 23 28 17 178 E 27 18 19 22 21 Amchitka Is. 400 mi 30 26 24 158 W 0 200 178 W Atka Unalaska Adak 174 W 162 W 0 200 400 km 170 W PACIFIC OCEAN
1. Wrangell 7. Snowy 13. Martin 19. Dutton 25. Makushin 31. Kanaga 2. Spurr 8. Griggs 14. Ugashik-Peulik 20. Isanostski 26. Okmok 32. Tanaga 3. Redoubt 9. Katmai 15. Ukinrek Maars 21. Shishaldin 27. Cleveland 33. Gareloi 4. Iliamna 10. Novarupta 16. Aniakchak 22. Fisher 28. Korovin 34. Cerberus 5. Augustine 11. Trident 17. Veniaminof 23. Westdahl 29. Kasatochi 35. Little Sitkin 6. Fourpeaked 12. Mageik 18. Pavlof 24. Akutan 30. Great Sitkin
Figure 1. Location of volcanoes mentioned in this report. Cerberus (34) and Little Sitkin (35) volcanic centers have subnetworks and are not on the list of permanently monitored volcanoes. Cleveland (27) and Kasatochi (29) erupted in 2008 and are not monitored by a seismograph subnetwork. All other volcanic centers are monitored by a seismograph subnetwork and listed in the weekly update of formally monitored volcanoes. Dots show locations referred to in this report.
Instrumentation period instruments during 2008. The instruments used at sites with three component sensors were Mark Products L22 seismometers with a 0.5-second period, Mark Products L4-3D The permanent AVO seismograph network is composed seismometers with a 1-second period, or Teledyne-Geotech of 24 subnetworks each with 4 to 20 seismograph stations and S13 seismometers with a 1-second natural period. Seventeen 9 regional seismograph stations (appendixes B and C) for a broadband stations were operated with either a Guralp CMG- total of 193 stations (table 2). Although no new seismograph 40T seismometer (frequency range: 0.033 to 50 Hz), Guralp subnetworks were added to the permanent AVO seismograph CMG-6TD seismometer (frequency range: 0.033 to 50 Hz), or network, there were several changes made in 2008. In Nanametrics Trillium 40 seismometer (frequency range: 0.025 conjunction with the establishment of GPS instrumentation to 50 Hz). The Augustine strong motion station (AU22) used by EarthScope’s Plate Boundary Observatory on Unimak a REFTEK 130-ANSS/02 strong motion sensor (frequency Island, several stations in the Shishaldin and Westdahl range: DC to 500 Hz). subnetworks were moved. In the Westdahl subnetwork, three The majority of the short-period stations were digitized at stations (WESS, WFAR, and WPOG) were removed and 100 samples per second (sps). The Cerberus and Little Sitkin three new stations (WESP, WECS, WEBT) were established subnetworks were recorded at 50 sps due to limitations in data in similar locations. In the Shishaldin subnetwork, the short- rates using very small aperture terminal telemetry between period station ISTK was relocated and renamed ISLZ and the recording hub located on Amchitka Island and Anchorage. a broadband station (SSBA) was installed. The only other Broadband stations were digitized at 50 sps with the exception change in the AVO network was the destruction of the of AUL, which is recorded at 100 sps. Typical calibration broadband station OKCD in the Okmok eruption in July. curves for short-period and broadband seismometers used The 154 single-component short-period seismograph in the AVO seismograph network are shown in figures 2-6. stations were equipped with either Mark Products L4 or Calibration information for each station is compiled in Teledyne-Geotech S13 seismometers with a 1-second natural the HYPOELLIPSE file caldata.prm included in a data period. AVO also operated 22 three-component, short- supplement to this report. Instrumentation 3
Table 2. Number of Alaska Volcano Observatory seismograph stations by type and year.
Number Number Number Number of Number of Number of of single- of three- of strong Year seismograph broadband components component component motion stations stations stations stations stations 1988 25 29 23 2 0 0 1989 28 32 26 2 0 0 1990 41 48 38 3 0 0 1991 35 41 32 3 0 0 1992 38 45 35 3 0 0 1993 43 50 40 3 0 0 1994 46 57 41 5 0 0 1995 56 66 51 5 0 0 1996 59 78 48 10 1 0 1997 95 124 82 12 2 0 1998 108 141 93 14 2 0 1999 121 155 105 14 2 0 2000 125 161 107 16 2 0 2001 138 176 119 17 3 0 2002 140 178 123 16 2 0 2003 160 216 134 18 9 0 2004 182 254 148 20 15 0 2005 188 265 150 23 15 0 2006 191 274 153 23 15 1 2007 193 280 154 22 17 1 2008 193 280 154 22 17 1
160
140
120
100
80 Figure 2. Log-log plot of 60 representative displacement response curves for the short-period stations using a Mark Products L4 or L4-3D 40 seismometer. The solid line illustrates the typical calibration curve and
System Amplitude Response (dB) 20 the dashed lines show the range of 0.10 1.00 10.00 100.00 calibration curves for all AVO stations Frequency (Hz) using L4 or L4-3D seismometers. 4 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
140
120
100
80
60
40
System Amplitude Response (dB) 20 0.10 1.00 10.00 100.00 Frequency (Hz)
Figure 3. Log-log plot of representative displacement response curves for the short-period stations using a Mark Products L22 seismometer. The solid line illustrates the typical calibration curve and the dashed lines show the range of calibration curves for all AVO stations using L22 seismometers.
160
140
120
100
80
60
0.10 1.00 10.00 100.00
System Amplitude Response (dB) Frequency (Hz)
Figure 4. Log-log plot of representative displacement response curves for the short-period stations using a Teledyne-Geotech S13 seismometer. The solid line illustrates the typical calibration curve and the dashed lines show the range of calibration curves for all AVO stations using S13 seismometers. Instrumentation 5
140
120
100
80
60
40
20 0.01 0.10 1.00 10.00 100.00
System Amplitude Response (dB) Frequency (Hz) Figure 5. Log-log plot of representative displacement response curves for the broadband stations using a Guralp CMG-40T seismometer. The solid line illustrates the typical calibration curve and the dashed lines show the range of calibration curves for all AVO stations using Guralp CMG-40T seismometers.
180
160
140
120
100
80
60 0.01 0.10 1.00 10.00 100.00
System Amplitude Response (dB) Frequency (Hz)
Figure 6. Log-log plot of representative displacement response curves for the broadband stations using a Guralp CMG-6TD seismometer. The solid line illustrates the typical calibration curve and the dashed lines show the range of calibration curves for all AVO stations using Guralp CMG-6TD seismometers. 6 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
Data from short-period seismograph stations were Event triggers were processed daily using the interactive telemetered using voltage-controlled oscillators (VCOs) seismic data analysis program XPICK (Robinson, 1990) to transform the signals generated by the seismometer (in and the earthquake location program HYPOELLIPSE (Lahr, response to ground velocity) from a voltage to a frequency- 1999). Each event trigger was visually inspected and false modulated carrier suitable for transmission over a radio link triggers were deleted. Each subsequent event was identified or telephone circuit. AVO primarily used VCOs developed by a description code (table 4) modified after Lahr and others by McChesney (1999) to modulate signals in the field. In (1994), which is stored as a comment in the event location rare cases, other VCO models were used, but these are being pick file. Earthquakes with a P-wave and S-wave separation replaced as stations are visited. Signals were transmitted via of greater than 5 seconds on the closest station were assumed UHF and VHF radio to communication hubs located in Adak, to come from non-volcanic sources and typically were not Akutan, Amchitka Island, Anchorage, Atka, Cold Bay, Homer, located. Each hypocenter was checked using a computer Kenai, King Cove, King Salmon, Port Heiden, Sourdough, algorithm that identified events that did not meet the following Tolsona and Unalaska (fig. 1). Data were then digitized at the minimum parameters: three P-phases, two S-phases, and Adak, Amchitka Island, Homer, Kenai, King Salmon, and standard hypocentral errors less than 15 km, as defined by Unalaska communication hubs and directed to AVO offices via Lahr (1999). If upon reevaluation, the minimum parameters high-speed digital circuits. From all other hubs (Akutan, Cold could not be met, the event was removed from the final Bay, Port Heiden, Sourdough, and Tolsona), analog signals catalog listing. For the earthquakes in the 2008 AVO catalog, were relayed via leased telephone circuits to AVO offices in the average root-mean-square travel-time error was 0.137 Anchorage or Fairbanks where the signals were subsequently second and the average hypocentral errors ERZ and ERH digitized. Data from broadband seismograph stations were were 1.41 and 2.29 km, respectively. Additional data from digitized at the station site and transmitted digitally using seismographs operated by the West Coast and Alaska Tsunami spread spectrum radios to communication hubs in Akutan, Warning Center and Alaska Earthquake Information Center Anchorage, Homer, King Salmon, and Unalaska. These data (AEIC) were routinely utilized in event detection and location. were forwarded to AVO offices in Fairbanks and Anchorage Station parameters for the West Coast and Alaska Tsunami via high-speed digital circuits. Warning Center and Alaska Earthquake Information Center Locations and descriptions for all AVO stations operated stations used by AVO in 2008 are found in appendix B. during 2008 are contained in appendix B. Maps showing the locations of stations with respect to individual volcanoes are contained in appendix C. Estimates of each station’s operational status for the catalog period are shown in Seismic Velocity Models appendix D. Other station information are available as part of the data supplement to this report. During 2008, AVO employed 12 local volcano-specific seismic velocity models and 1 regional seismic velocity model to locate earthquakes at Alaskan volcanoes. All velocity models were one-dimensional models utilizing horizontal Data Acquisition and Processing layers to approximate the local seismic velocity structure. Each model, with one exception, assumed a series of constant Data acquisition for the AVO seismograph network velocity layers. The single exception was the Akutan velocity was accomplished with duplicate EARTHWORM systems model (Power and others, 1996), which had a velocity gradient (Johnson and others, 1995) located in Anchorage and in a layer overlying a half-space of constant velocity. Fairbanks. Data were recorded in both continuous and event One or more vertical cylindrical volumes were used detection modes. Event detected data were collected using to model the volcanic source zones for all volcanoes where the EARTHWORM modules, Carlstatrig and Carlsubtrig a local velocity model was used. Earthquakes within these with the Carlstatrig parameters set as follows: Long-term- cylindrical volumes were located with a local model and average (LTA) time = 8 seconds, Ratio = 2.3, and Quiet = 4. earthquakes outside of the cylindrical volumes were located Three station triggers from the Carlstatrig module are required with the regional model. All cylindrical volumes had a radius for an event to trigger Carlsubtrig to create an event record. of 20 km with the exception of the cylinders centered on Carlsubtrig was modified such that a two-letter code (table 3) Shishaldin and Mount Veniaminof. The cylinder centered was appended to the filename of each trigger to identify the on Shishaldin had a radius of 30 km in order to encompass first subnetwork that triggered. If four or more subnetworks Fisher Caldera and Isanotski Peaks. The cylinder centered on triggered on the same event, all data were saved in a single Veniaminof also had a radius of 30 km because of the large trigger and tagged as a regional event. All data are saved in size of the volcanic edifice. The top of each cylinder is set at Seismic Analysis Code format (Goldstein and others, 1999). 3 km above sea level and the bottom is set at a depth of 50 km below sea level. Seismicity 7
Table 3. Volcano subnetwork designators. The Akutan, Augustine (Power, 1988), Iliamna (Roman and others, 2001), Okmok (Searcy and Prejean, U.S. [For seismograph stations installed in 2003 and later, the network code is also Geological Survey, written commun., 2009), Tanaga (J.A. used as the first two letters of the station code] Power, U.S. Geological Survey, written commun., 2005), Volcano Network Volcanoes monitored Veniaminof (Sánchez, 2005), and Westdahl (Dixon and others, subnetwork code 2005) velocity models were used to locate hypocenters that fell within cylindrical volumes described above, centered Akutan ak Akutan Volcano on each respective volcano. The Cold Bay velocity model Aniakchak an Aniakchak Crater Augustine au Augustine Volcano (McNutt and Jacob, 1986) was used to locate earthquakes that Cerberus ce Mount Cerberus fell within cylindrical volumes centered on Mount Dutton Dutton dt Mount Dutton and Pavlof Volcano. Earthquakes at Fisher, Isanotski, and Iliamna il Iliamna Volcano Shishaldin that fell within the cylindrical regions centered Fourpeaked fo Fourpeaked Mountain on Shishaldin Volcano also were located using the Cold Gareloi ga Mount Gareloi Bay velocity model. Five overlapping cylinders defined the Great Sitkin gs Great Sitkin Volcano volume in which the Spurr velocity model (Jolly and others, Kanaga ki Kanaga Volcano 1994) was used, four overlapping cylinders defined the Katmai ka Mount Griggs, Mount Katmai, volume for the Redoubt velocity model (Lahr and others, Mount Mageik and Mount Martin, Novarupta, Snowy 1994), and four overlapping cylinders defined the volume for Mountain, and Trident Volcano the Katmai model (Searcy, 2003). The Andreanof velocity Korovin ko Korovin Volcano model, modified from that in Toth and Kisslinger (1984), was Little Sitkin ls Little Sitkin Volcano used to locate earthquakes within a volume defined by three Makushin ma Makushin Volcano cylinders centered on Kanaga Volcano, Mount Moffet, and Okmok ok Okmok Caldera Great Sitkin Volcano. Specific velocity models for Aniakchak Pavlof pv Pavlof Volcano Peulik pl Ugashik-Peulik and Ukinrek Maars Crater, Mount Cerberus, Mount Gareloi, Korovin Volcano, Redoubt rd Redoubt Volcano Little Sitkin Volcano, Makushin Volcano, Mount Peulik, and Regional Event rg none Mount Wrangell were not available in 2008 and the regional Shishaldin sh Fisher Caldera, Isanotski Peaks, and velocity model (Fogleman and others, 1993) was used to Shishaldin Volcano locate earthquakes near these volcanoes. The cylindrical Spurr sp Mount Spurr model parameters, regional velocity model, and volcano- Tanaga ta Tanaga Volcano specific models used to locate earthquakes in this report are Veniaminof vn Mount Veniaminof Westdahl we Fisher Caldera, and Westdahl Peak summarized in appendix E. Figures showing the volcanic Wrangell wa Mount Wrangell source zones modeled by multiple cylinders are shown in appendix F.
Table 4. Alaska Volcano Observatory event description codes. Seismicity [Lowercase letters refer to triggered events that are located. Uppercase letters are used for triggered events that are not located] The 7,097 earthquakes located in 2008 represent an Event classification Classification code increase from the 6,664 earthquakes located in 2007 (Dixon and others, 2008). Of the earthquakes located in 2008, Volcano-Tectonic (VT) a 75 percent (5,318 earthquakes) were located within 20 km of Low-Frequency (LF) b Hybrid h a monitored volcanic center. The numbers of located events Shore-Ice i at volcanic centers in the last 2 years, listed by seismograph Cause unknown x subnetwork, are shown in table 5. Regional-Volcanic R Using the 2008 earthquake catalog, the magnitude of Regional-Tectonic E completeness (Mc) for each subnetwork was calculated with Teleseismic T the exception of six subnetworks (table 5). The Aniakchak, Glacier G Dutton, Fourpeaked, Pavlof, Veniaminof, and Westdahl Calibrations C Other non-seismic O subnetworks had insufficient numbers of located earthquakes (less than 20) to calculate a Mc. The Mc ranged from -0.5 to 1.7 for the individual subnetworks. Mc is the magnitude threshold above which we are reasonably certain that an event of Mc or greater was detected. The Mc was determined using a maximum likelihood estimate of the inflection point in the frequency magnitude distribution using the seismology analysis software ZMAP (Weimer, 2001). 8 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
Table 5. Number of earthquakes located for each seismograph subnetwork in 2007 and 2008 within 20 km of the volcanic centers in each subnetwork.
[The totals for 2008 are broken into three event types: volcanic-tectonic (VT), low-frequency (LF) and other (all other possible event types shown in table 4). Magnitude of completeness (Mc) for AVO seismograph subnetworks used the 2008 data]
Earthquakes Earthquakes 2008 2008 2008 2008 Volcano subnetwork located in 2007 located in 2008 VT LF Other Mc Akutan 58 105 101 3 1 0.3 Aniakchak 1 1 1 0 0 (1) Augustine 367 116 113 1 2 0.1 Cerberus 42 21 21 0 0 0.8 Dutton 17 19 19 0 0 (1) Fourpeaked 272 11 10 0 1 (1) Gareloi 1,461 87 86 0 1 1.7 Great Sitkin 52 33 33 0 0 -0.5 Iliamna 106 102 95 7 0 0.7 Kanaga 48 478 403 0 75 1.2 Katmai Cluster 1,375 1,987 1,974 13 0 0.5 Korovin 293 47 46 0 1 1.3 Little Sitkin 217 235 235 0 0 0.4 Makushin 136 117 116 1 0 0.7 Okmok 84 635 608 26 1 1.1 Pavlof 48 9 4 5 0 (1) Peulik 29 21 20 1 0 1.3 Redoubt 41 107 39 68 0 0.2 Shishaldin 42 290 279 11 0 0.9 Spurr 768 599 545 54 0 0.1 Tanaga 47 401 332 1 68 1.1 Veniaminof 4 17 14 3 0 (1) Westdahl 6 11 9 2 0 (1) Wrangell 147 83 15 68 0 1.0 Totals 5,666 5,318 4,903 266 149 (1) 1 Insufficient number of located earthquakes and therefore an Mc could not be computed.
In 2008, the Volcano Alert Level and Aviation Color In July, there was an increase in activity detected on the Codes were raised at three monitored volcanic centers Great Sitkin subnetwork in the vicinity of Kasatochi Volcano (Okmok Caldera, Redoubt Volcano, and Mount Veniaminof). (fig. 1), a seismically unmonitored volcano. On August 6, the The eruption at Okmok (Neal and others, 2009) started earthquake activity at Kasatochi rapidly increased (Ruppert with an abrupt increase in seismicity at 1400 UTC July 12 and others, 2008). The following day, the seismicity was cumulating with the start of the eruption at 2143 UTC. The accompanied by periods of volcanic tremor and cumulated in seismicity peaked at 2200 UTC on July 12 after which it an eruption later that day. Two days later the intense seismic gradually declined until the seismicity at Okmok was back activity associated with the Kasatochi eruption declined. All to its pre-eruption levels in mid-November. Several minor 1,553 earthquakes located within 20 km from Kasatochi in ash bursts from Veniaminof were recorded in seismic data in 2008 (fig. 7) are available from the AEIC catalog (Ruppert, February with all reported activity ending in April. Weak but 2008b). Only 58 earthquakes within 20 km of Kasatochi were anomalous seismicity was detected at Redoubt in October. located by AVO as the majority of the located seismicity The increased seismicity along with observations suggesting falls outside the AVO guidelines for inclusion in the AVO increased heat flow prompted an increase in the Volcano Alert earthquake catalog. Level and Aviation Color Code for Redoubt on November 5. The increase in located seismic activity within the Katmai The eruption of Okmok and the increased unrest at Redoubt subnetwork is related to substantial increase in activity in the and Veniaminof resulted in more earthquakes located at these vicinity of Trident Volcano and Mount Mageik. In 2007, 338 volcanoes in 2008 than the previous year. earthquakes were located within 5 km of Trident whereas in Seismicity 9
2008, the number of located events was 625. 176 W 175 W 174 W Likewise, there was a doubling of located earthquakes at Mount Mageik in 2008. A total of 217 earthquakes were located within 5 km Kasatochi in 2007 and 400 were located in 2008. The Great Sitkin Atka Island increase in earthquake activity at Shishaldin started in October and continued into 2009, Island where the Volcano Alert Level and Aviation Color Code were raised just after the end 52 N 52 N of 2008. The Pavlof subnetwork showed an apparent decrease in the number of located earthquakes in 2008. In January 2007, a swarm 7 Aug 2008 Mag=5.8 of earthquakes 15 km northeast of Pavlof accounted for the abnormal high number of km earthquakes located in 2007. 0 50 The apparent decrease in detected seismic activity at the Augustine, Spurr, and 176 W 175 W 174 W Fourpeaked subnetworks likely is related to Figure 7. Earthquakes located by AEIC associated with the Kasatochi the continued decrease in activity following eruption (Ruppert, 2008b). The focal mechanism shown is for the largest the respective periods of unrest. The earthquake (Mw=5.8) shown by the star. Kasatochi Volcano is shown by numbers of located earthquakes in 2008 at the inverted triangle. these subnetworks are similar to those years preceding their respective eruption/unrest. Subnetworks at Akutan and Westdahl show an increased number of located earthquakes when compared to those located in 2007. km 2 May 2008 Mag=6.6 When compared to the located seismicity prior 0 20 to 2007, the number of located earthquakes in 2008 is similar and does not appear to represent a significant change in seismicity. 52 N Four subnetworks (Cerberus, Gareloi, Korovin, and Wrangell), saw a decrease in the number of located earthquakes in 2008 compared to the number of earthquakes located in 2007, which could be due to prolonged station outages. The number of Kanaga Island located earthquakes at Gareloi was down Tanaga Island Adak Island substantially compared to the number located in 2007. Winter storms generally reduce the 178 W 177 W number of events that can be located and starting late spring, the number of operating Figure 8. The May 2, 2008 Mw=6.6 earthquake with aftershocks and seismograph stations was below the minimum triggered seismicity located by AEIC (Ruppert, 2008a). The earthquakes for an earthquake location to be included shown in the red circles are within 20 km of either the Kanaga or in the catalog. Two subnetworks (Tanaga Takawanga volcanic centers. and Kanga) showed an increase in located earthquake due to a nearby large tectonic earthquake on May 2, 2008 (Mw=6.6) and subsequent aftershocks and triggered seismicity (fig. 8). The number of located earthquakes at the Aniakchak, Dutton, Great Sitkin, Iliamna, Little Sitkin, Makushin, Peulik, and Veniaminof subnetworks were similar to those in 2007. 10 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
Summary Fogleman, K.A., Lahr, J.C., Stephens, C.D., and Page, R.A., 1993, Earthquake locations determined by the southern Alaska seismograph network for October 1971 through May Between January 1 and December 31, 2008, AVO 1989: U.S. Geological Survey Open-File Report 93-309, located 7,097 earthquakes of which 5,318 occurred at or near 54 p. volcanoes in Alaska. Monitoring highlights in 2008 include the eruptions of Okmok Caldera and Kasatochi Volcano, as Goldstein, P., Dodge, D., and Firpo, M., 1999, SAC2000: well as increased unrest at Mount Veniaminof and Redoubt Signal processing and analysis tools for seismologists and Volcano. engineers, in Lee W.H.K., Kanamori, H., Jennings, P.P., Available for download with this report is a compressed Kisslinger, C., eds., International Handbook of Engineers Unix tar-file containing a summary listing of earthquake and Engineering Seismology, v. 81B, San Diego, CA, hypocenters and all necessary HYPOELLIPSE input files to Academic Press, p. 1613-1614. recalculate the hypocenters including station locations and calibrations, seismic velocity models, and phase information. Johnson, C.E., Bittenbinder, A., Bogaert, D., Dietz, L., and The reader should refer to Lahr (1999) for information on Kohler, W., 1995, EARTHWORM: A flexible approach to file formats and instructions for configuring and running the seismograph network processing: Incorporated Research location program HYPOELLIPSE. Continuous waveform Institutions for Seismology Newsletter, v. 14, no. 2, p. 1-4. data for selected AVO seismograph stations are archived and Jolly, A.D., Page, R.A., and Power, J.A., 1994, Seismicity and available through the Incorporated Research Institutions for stress in the vicinity of Mt. Spurr volcano, south-central Seismology (IRIS) (www.iris.edu). Archives of waveform data Alaska: Journal of Geophysical Research, v. 99, p. 15305- are maintained on DVD-ROM at AVO offices in Fairbanks 15318. and Anchorage. AVO earthquake catalogs for 1989–2007 are listed in Lahr, J.C., Chouet, B.A., Stephens, C.D., Power, J.A., and appendix G. Selected papers published in 2008 that utilized Page, R.A., 1994, Earthquake classification, location, and AVO seismic data are listed in appendix H error analysis in a volcanic environment: Implications for the magmatic system of the 1989–90 eruptions at Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Acknowledgments Research, v. 62, p. 137-152. Lahr, J.C., 1999, HYPOELLIPSE: A computer program for The contents of this report reflect a great deal of hard determining local earthquake hypocentral parameters, work by a large number of people including AVO, Alaska magnitude, and first motion pattern: U.S. Geological Survey Earthquake Information Center (AEIC), and USGS personnel Open-File Report 99-23, 116 p. and various students, interns, and volunteers. We thank the AEIC and the West Coast and Alaska Tsunami Warning Center McChesney, P.J., 1999, McVCO Handbook 1999: U.S. for the use of their data. We thank John Power, Rick Wessels Geological Survey Open-File Report 99-361, 48 p. and Dave Wilson of the U.S. Geological Survey for formal reviews of the text and figures. McNutt, S.R., and Jacob, K.H, 1986, Determination of large- scale velocity structure of the crust and upper mantle in the vicinity of Pavlof Volcano, Alaska: Journal of Geophysical Research, v. 91, p. 5013-5022. References Cited Neal, C.A., Larsen, J.F., and Schaefer, Janet, 2009, The July-August 2008 hydrovolcanic eruption of Okmok Dixon, J.P., Power, J.A., and Stihler, S.D., 2005, Seismic Volcano, Umnak Island, Alaska: Alaska Geological Society observations of Westdahl Volcano and Western Unimak Newsletter, v. 39, no. 5. Island. Alaska: 1999–2005, [abs.]: American Geophysical Union Transactions, v. 86, Fall Meeting Supplement, Power, J.A., 1988, Seismicity associated with the 1986 Abstract S11b-0169. eruption of Augustine Volcano, Alaska: Fairbanks, University of Alaska Fairbanks, Masters Thesis, 149 p. Dixon, J.P., Stihler, S.D., and Power, J.A., 2008, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1 Power, J.A., Paskievitch, J.F., Richter, D.H., McGimsey, R.G., through December 31, 2007: U.S. Geological Survey Data Stelling, P., Jolly, A.D., and Fletcher, H.J., 1996, 1996 Series 367, 82 p. seismicity and ground deformation at Akutan Volcano: American Geophysical Union Transactions, v. 77, p. F514. References Cited 11
Robinson, M., 1990, XPICK users manual, version 2.7: Sánchez, J.J., 2005, Volcano seismology from around the University of Alaska Fairbanks, Seismology Lab, World: Case studies from Mount Pinatubo (Philippines), Geophysical Institute, 93 p. Galeras (Columbia), Mount Wrangell and Mount Veniaminof (Alaska): Fairbanks, University of Alaska Roman, D.C., Power, J.A., Moran, S.C., Cashman, K.V., and Fairbanks, Ph.D. dissertation, 208 p. Stihler, S.D., 2001, Unrest at Iliamna Volcano, Alaska in 1996, Evidence for a magmatic intrusion [abs.]: American Searcy, C.K., 2003, Station corrections for the Katmai Region Geophysical Union Transactions, v. 82, p. F1329. seismograph network: U.S. Geological Survey Open-File Report 03-403, 16 p. Ruppert, N.A., 2008a, Earthquakes in Alaska May 2008, Alaska State Seismologist’s Report 2008-05. Toth, T., and Kisslinger, C., 1984, Revised focal depths and velocity model for local earthquakes in the Adak seismic Ruppert, N.A., 2008b, Earthquakes in Alaska August 2008, zone: Bulletin of the Seismological Society of America, Alaska State Seismologist’s Report 2008-08. v. 74, p. 1349-1360. Ruppert, N.A., Hansen, R.A., West M., and Prejean, S., Wiemer, S., 2001, A software package to analyze seismicity: 2008, Seismic swarm associated with the 2008 eruption of ZMAP: Seismological Research Letters, v. 72, p. 373-382. Kasatochi Volcano, Alaska, [abs.]: American Geophysical Union Transactions, v. 89, Fall Meeting Supplement, Abstract A53B-0261. 12 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
This page left intentionally blank Appendix A 13
Appendix A. Maps of Monitored Volcanoes with Earthquake Hypocenters Calculated in 2008.
Mount Wrangell Seismicity
62.4
Sanford ... 62.2 0 0 Drum ... o WAZA g L 0 a ~oo 62"N 00 WACK ~angell ti620 . o g~ . Cb cP I O~\O u o t ~ d 0 0 e 61.8 Blackburn... 61"N40 20 km 61.6
0 10 20 145"W 00 144"W 30 144"W 00 143"W 30 143"W 00 Depth (km)
Mag. Symb. Size -5 0 0 • 0 1 E 2 0° "'- 5 :~ ~ 0% 3 0 ~ 10 008" 0 0 4 0 0 15 fl>e9 5 0 20 -145.0 -144.5 ~ -144.0 -143.5 -143.0 Longitude
-5 0 o 0_ - 0 9 . oa ~3° ooo~ E o 0 000e eo 0 "'- 5'°,p00 0 ~8~ ~ CIP 0 ° ° &.0 0 0 e 0 o. 0 0 0 ! lOp 0 0 0 0 ° 0 15 gO °0 0 , 20 Jan 2008 Mar Apr ~ay Jun Jut Aug Sep Ocl Nov Dec Date Figure A1. Summary plots of earthquakes located near Mount Wrangell in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 14 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008
Mount Spurr Seismicity
a NCG 61.4 0
SPNW 0 :- .' o a ,,~r.." qj o o • , a CGL 61.3 o • 0 J., Spurr a 0 SPWEo BGL "T'GI"' 0 SPCG ~00 0 oi;;~,J' CRP o o S~Go L o "-o;p...... '" • a .,. ..., TV. ·eo I ,. ." CKL • "-CKN •• i 61 N 12 ~ oC~ I 61.2 o • ~ 0 o • P<;R "a SPU u o , .. d 8~:'~ e • 40 .. o o o o , 61.1 o • ~1JKG _~_(ll 'lI 0 killm_. £40 ~o o ...
61 NOD ...... "---'-_0_...... __...... 61.0 L-~---,,_~-,o'--- Mag. Symb. Size -5 • 0 OJ • .. o • 0 1 o E 2 6 5 o .c 0 ;:~.~:: 3 o g. 10 r i~ 0 4 cf' 00 0 o 15 o 1'0 • 0 0 5 o o 0 o 20 -152.6 -152.4 -152.0 Longitude -5 "----,--,--r-r-,--'--'-----,,----,---rl,-,----,-,--,--,,,----,--,--r-r,-,----,--,--,,----,----,--r-r---,----,---,---, _0 • 0 0 _0 • .it. 0 0 _0 Ato o. iIII 0 0 • 0 O. • ~~tir~~0~~~~i,te:\~~:·8.' ,," 0... .. 0 aa",c9 & 0:···· 0 O' 0 0, 0 "":'b o'll. .0 0 0 0 0" 0 ~o 0 0 00 &. 0 0 or 0 ... d 0 0 0 0 cfJ 00 0 0 0 • 0 0 0.. o 0 0 20 "nr--'---.JL.lL.l-,--'lr-'----'-----L---'----...'T---'----'-----'----'f'-'--'v--4r---'--....,r-,-L'0"----'----'----'VL--'---L-L-L-'-'C~ Jan-2008 Mar Apr ay Jun ul Aug Sep Oct Nov Dec Dale Figure A2. Summary plots of earthquakes located near Mount Spurr in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 15 Redoubt Volcano Seismicity 60 N 39 o DFR 606 0 .,.. a a 0 00 a ROT a 0.- NeT o. .0 60 N 33 0: 0 000 t) • ROlli ~. o. 0 L 0 a I'- tl 0 0 "V~o'\ 0 t q,0 0 • 0 60.5 • 0 0 -.REF.fll i ~ t Redoubt o· u 60 N 27 o RSO V d 0 o e 0 o 0 0 60A 0 60 N 21 o 1 km 0 60.3 o , 0 10 20 152 W 54 152 W 42 152 W 30 152 W 18 Depth (km) Mag. Symb. Size -5 0 . «- 0 0 0 0 0 .. 1 0 Oo~ 0 E 0 o 0. ~ 0 0 0 0 5 0 ,,0 2 6 0 0 s 0 ~o 0 3 0 g. 10 0 0 0 0 0 ~ 0- 4 0 0 15 0 5 0 20 -15?i.0 .!'152.'!l ' -152.6' -152.4 Longitude -5 , , 0' , od o ••• oo 0 0 0 E 0 °:B:~~f 0 5 0 .0 6 0 0 0 .c 0 0 10 d' 0 • - 0 g. 0 0 0 0 0 0 0 1) 15 0 , 20 Jan-200B Mar Apr May Jun Jul Aug Sep OcT Nov'" Dec ... Date Figure A3. Summary plots of earthquakes located near Redoubt Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 16 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Iliamna Volcano Seismicity 60 N 12 60.2 o 60 N 06 L 60.1 • INE'l. a III a ILWa ,po I lIiamna~e: i I ~aIVE u o 60 N 00 IVS 0 0 0 d 60.0 e a ILS o 59 N 54 59.9 o 0 10 km 0 10 20 153 W 20 153 W 00 152 W 40 Depth (km) Mag. Symb. Size -5~-~--~-~--~-~--~-~--~~ ~o 0 o ci ' 1 0- -"tIro' 2 0 I 5 o o 0 .c 3 0 ~ 10 o 4 0 15 5 0 -153.4 -153.2 -153.0 -152.8 Longilude -5 r-T~---r---,---,-~,---,c-r-T---r---r--,-~--,-,--,--,r-r~---r--,---,--,--,--r-r-T---r~~-,----,-,--,---, o .'O~•. o o o qp I 5 o .c ~ 10 t o 15 20 '---'---'---'----'----'----'---L-J'-----'---'---'-----'----'----'----'---.l-L...JL..L-L---'----'---'-----'----'--L---'---'---'-----'----'----'----'---.l-'------' Jan-2008 Mar Apr May Jun Jut Aug Sep Oct Nov Dec Dale Figure A4. Summary plots of earthquakes located near Iliamna Volcano in 2008. Open circles scaled with magnitude show hypocenter locations. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 17 Augustine Volcano Seismicity 59.42 , 59 N 24 59.40 AUL a L 59.3B AUE a AUW Alfustine a I a 0 59'N 22 a i A'aAUP AU22 I AUH. t u 59.36 d f e 59.34 AUla 59'N 20 V • 59.32 5km 59 N 18 0 10 20 153 W 33 153 W 27 153 W 21 Depth (km) Mag. Symb. Size -5 . a 0 0 ., 1 0 E 2 0 6 5 3 0 ""~ 10 0 4 0 15 5 a 20 -153.55 -153.50 -153.45 -153.40 -153.35 Longilude -5 0 0 ... 00 ~., 0 • O• .. • o· ~o .t _ .•.. 0 0 , .. t. os • .,. '1>·1 E 6 5 ""g. 10 0 15 , ,, 20 Jan-200B Mar Apr .,. May Jun Jul Aug Sep Oct Nov Dec Dale Figure A5. Summary plots of earthquakes located near Augustine Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 18 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Fourpeaked Mountain Seismicity CDDa 58 N 54 o 58.9 0 0 0 0 FONWa FOSS L o a a 5B.B 0 o Fourpeaked o t 0 0 A aFOPK i t 0 u 0 o , d 58 N 42 e 5B.7 o 0 ...Kaguyak Crate~ 58 N 36 5B.6 10 km 0 10 20 154°W 00 153°W 40 153°W 20 Depth (km) Mag. Symb. Size -5 0 • 0 1 0 E 0 00 5 0 2 0 ~ 0 rc 0 0 0 3 0 0 0 ~ 10 0 6> 0 4 0 15 5 0 20 -154.0 -153.B -153.6 -153.4 Longitude -5 , 0 - 0 E 0 ~ 0 rc 5- 0 0 0 g. 10 0 0 0 0 8 15 20 Jan-200B Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A6. Summary plots of earthquakes located near Fourpeaked Mountain in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 19 Katmai Volcanic Cluster Seismicity 0 0 O 5S"N 40 KAHC db ,&0 0 "b 0 o 0 0 0 0 §' 0 0 5S"N 00 00 58.0 0 20 km y 0 0 0 0 57.8 0 10 20 155"W 45 155"W 15 154"W 45 154"W 15 Depth (km) Mag. Symb. Size 0 • 1 0 ~ 5 2 0 ~ 3 0 g. 10 0 0 0 4 0 15 0 0 0 5 • 0 0 20 -1558. -155.4 -155.0 -154.6 -154.2 Longitude L.J~M..:'a-y-'---L-,-JuLn-'-----'---JLul--'----'--:A-'-Ug--'--4s~er-p-'---Lo-:c""t-,--:e..."NLov--'-'~o"'ec-"r----" 20JLa-'-n_--:2:'::0"'08:'-'r--"C-M"-a--',Y"A-'-P-' Dale Figure A7. Summary plots of earthquakes located near the Katmai volcanic cluster in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 20 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Snowy Mountain Seismicity 'b' 0 0 58 N 30 a .KAHG 0 58.5 ~RR 0 ge 0 0 0 0 0 00 0 . CD 0 0 0 0 0 0" 0 00 0 0 01... : 0 '-80 0000 0 L 0' 0 ~.o 0 Steller o :0 o 0" 00 tD a 58°N 24 0 t 58.4 0 '0 0 00 0 8 0 0 i t .~ 00 0 Y 0 u 0 o .Ql V d ~ "~o o oeo e 010 .: Snowy :. 0 0 0 0 ~ ~ 0 :0 0 58°N 18 58.3 0 5km .(> 0 10 20 154 W 48 154 W 36 154 W 24 Depth (km) Mag. Symb. Size -5 0 0 0 0 1 0 2 0 I 5 ~~ee;:':~ 80& <'O~ o~ole ~ 0 .c 00 3 0 0.. 10 o 0 0 0 0 s et ~ 0 4 0 15 5 0 20 -154.8 -154.7 -154.6 -154.5 -154.4 Longitude -5 0 0 0 0 ~oo ~ 0 0 0 0 0 0 o~~g~ 8 E 0 0 ~: ~o~o o~~ ~Q) 0 6 5 0 0 0 0' .c 0 ~o"o 0 0 0 0 0 g. 10 0 0 0 • 15 Mar Jun Jul Aug Sep Oel Nov Dec Date Figure A8. Summary plots of earthquakes located near Snowy Mountain in the Katmai volcanic cluster in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 21 Mount Griggs Seismicity 58 N 28 ,.--...---...... - ...... ---.---...---...... , o 58.44 o v 0 0 L 58.4C 58°N 24 0 0 a t i 0 t 00 0 0 u d 58.36 0 e 0 0 ~Griggs 0 0 0 58°N 20 0 0 • 0 0 0 58.32 0-, 0• 0 KeG 0 °fKm o 0 •0 a L 00 0 0 0 10 20 155°W 06 155°W 00 154°W54 Depth (km) Mag. Symb. Size -5 0 a 0 0 0 1 0 E 0 • 2 0 6 5 • 0 0 t 'Iv 0 oes ~ 0 3 0 g. 10 0 4 0 15 5 0 20 • -155.1 -155.0 -154.9 Longitude -5 , ,, 0 0 0" ~..g- 00 0 0 E ~ "0 0° 0 0 6 5 0 0 0 0 ~ 0 g. 10 0 15 20 Jan-2008 Mar ... Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A9. Summary plots of earthquakes located near Mount Griggs in the Katmai volcanic cluster in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles show hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Several earthquakes that appear on this figure appear on other figures. 22 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Mount Katmai Seismicity 0 QO 0 0 o 0 0 0 0 oCb 58.30 58'N 18 oKAKN 0 0 0"0 0 o 0 0 0 ,~0., f 0 oi \; 58.28 o 0 oelD 0 o~ oo~ 0 0 58 N 16 .0 0 0 L 0 0 ~ • 0 Katmai 00 a 58.26 0 0 0 8 0 0 0 t °0°£ 0 0 0 i Clti 0 0 o 0 0 0 t t 0 ~ 0 0 0 U 58.24 o . IJ 0 o 0 d 0 58 N 14 e 0 0 o 0 0 GO 58.22 0 Ibo 0 0 0 58 N 12 58.20 5km 0 10 20 155 W 03 154 W 57 154 W 51 Depth (km) Mag. Symb. Size -5 0 ~ 0 0 .0 0 00. 0 0 .0 08_ 0 0 ciO~SO 1 0 - olli 0 ... 00 ell 8lc g 50 0 0 2 0 s= 00 o 0 0 3 0 0 ~ 10 00 0 0 4 0 15 5 0 20 -155.05 -155.00 -154.95 -154.90 -154.85 Longitude 15 20 "---"--L-L---'-----'----'---L-J--L-L-L-"---"--L-L---'-----'-----'----'----L---'---J-L-J-"---'-----'--L---'----L---'----'----'---L-~ Jan-2008 Mar Apr May Jun Jul AU9 Sep Oct Nov Dec Date Figure A10. Summary plots of earthquakes located near Mount Katmai in the Katmai volcanic cluster in 2008. Open circles scaled with magnitude show hypocenter locations. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Several earthquakes that appear on this figure appear on other figures. Appendix A 23 NovaruptalTrident Volcano Seismicity o a o KeG 58.30 58 N 18 o .8 0 • • 0 o o KBM 58.28 a Novarupta o o 58 N 16 OA L 58.28 :·f 05> rJ 0 a 0 0 o 0 o t o 0 o o i • ·0 0 o o t o g. 0 u 58 N 14 o....,Q .0 d J~"'-Trident 0 e ~.o 0 ...... 0 ",0 0 _ o ""V'" 0_ 0.,-. • lb. 0 58 N 12 o 58.20 a ... 0 • 2km • 0 o. o 10 20 Depth (km) Mag. Symb. Size -5 o o • ,*,0 o o 0 o " :...... A··· o· 0 ~. 80 1 o 0 . o~ E 0 ..' ....." ; o 2 ~ 5 . .. .' o 0 o o 0 ~ 0 0 : 3 o g. 10 4 0 o 15 5 o 20 -155.20 - 5.1 -155.10 -155.05 -155.00 Longitude 15 Mar Apr May Jun Jul Aug Sep Nov Dec Date Figure A11. Summary plots of earthquakes located near Novarupta and Trident Volcano in the Katmai volcanic cluster in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Several earthquakes that appear on this figure appear on other figures. 24 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Mount Martin/Mount Mageik Volcano Seismicity 58.26 0 0 0 58 N 14 58.22 'f: ACH 0 0 a • ~ . L a • ageik I i I 0 u 58 N 10 • d e 0 0 0 0 • MGLS 58.14 .. 0 • '. 0 a •. cf> 0 0 .0 5km 80 • 0 0 • 58'N 06 • 58.10 • 0 10 20 155 W 27 155 W 21 155'W 15 155'W09 Depth (km) Mag. Symb. Size -5 0 • 0 • 0 ·0· 1 0 E 2 0 6 5 .. ~ • 0 3 0 g. 10 0 0 4 0 15 5 0 20 -155.4 -155.3 -155.2 Longilude ~ g. 10 o 15 20 L.L___'_---'-....--"---'---.L_L_L....<---'----'---'----"----"--_L_.L_"--"---"---'___'_--'--~'-'---L--L-.L-L-L....<---'----'---'----'---.J Jan-200B Mar Apr May Jun Jul Aug Sep Oct Nov Dec Dale Figure A12. Summary plots of earthquakes located near Mount Mageik and Mount Martin in the Katmai volcanic cluster in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Several earthquakes that appear on this figure appear on other figures. Appendix A 25 Mount Peulik Seismicity , 0 0 aPLWL 0 0 aPLK5 0 0 58.0 58 N 00 8 • 08 0 0 0 57.9 0 0 ~The Gas Rocks 0 0 Ukinrek~ 0 0 0 PLK1a 0 L 57.8 0 5iN 48 PLK20 a 0 t Ml Peullk6 a 0 i ~PLKi ~ t PLBLa tJ (J) CO 57.7 or-.o 0 u o • PLK4 cSlO 0. 0 d o.:1. 6'0 0 a . 0 e . ·0 ~tUgashlk 0 '0 57 N 36 0 57.6 0 0 0 19 km 57.5 0 0 57.4 57 N 24 0 10 20 156 W 50 156 W 30 156 W 10 -155 W 50 Depth (km) Mag. Symb. Size -5 0 0 9 0 • 0 1 0 0'0 0 E 0 0 :~t1 2 0 ~ 5 0 0 0 0 .c 0 0 0 0 9' 0 -5 0 b 0 0 0 0 ~ 0 E 00 0 0 ~ 5 0 00 0 ~ 0 0 .c 0 0 ~0ilI0 0 0 g. 10 0 0 0 0 00• 0 15 0 20 Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A13. Summary plots of earthquakes located near Mount Peulik in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 26 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Aniakchak Crater Seismicity ANNW a 56'N 57 56.95 ANONa aANNE ..1931 Vent 56.90 AZACa L a AVent Mountain t i t 56'N 51 u 56.85 0 a d 0 ANPK e a ANPB 56.80 5km 56.75 56 N 45 0 10 20 158 W 12 158 WOO Depth (km) Mag. Symb. Size -5 0 • 0 1 0 E 2 0 ""- 5 .c 3 0 ~ 10 0 0 4 0 15 5 0 20 -158.3 -158.2 -158.1 -158.0 Longitude -5 ,, ,,, 0 .... - E ""- 5 :; at 10 0 0 15 ,, ,,,, 20 ' Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A14. Summary plots of earthquakes located near Aniakchak Crater in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 27 Mount Veniaminof Seismicity 56.4 0 0 56.3 0 00 0 0 o 0 VNFGo o~ °VNNF go 0 00 0 ~QJ VNSS L VNHG 19 0 0<9 0 a ° ~ 56 N 12 Veniaminof 0 I 56.2 cPo 0 i 0 I VNWFo 0 0 aVNSG u d e 56.1 VNSWa a 0 VNKR 56 N 00 56.0 10 km 55.9 0 0 10 20 159 W 40 159 W 20 159 W 00 Depth (km) Mag. Symb. Size -5 0 0 0 . o· 0 1 0 E 0 2 0 C- 5 0 .c OSo 3 0 10 6JcP g. CO e 4 0 0 0 15 0 0 5 0 oa 20 -159.8 -159.6 -159.4 -159.2 -159.0 Longilude -5 , , , ,,,, 0 ··0 ...... 0 E 5 0 C- o 0 0 .c 0 8 0 g. 10 CO 0 0 0 0 0 0 15 0 0 00 20 Jan-200B Mar Apr May Jun Jul Aug Sep Oct Nov Dec Dale Figure A15. Summary plots of earthquakes located near Mount Veniaminof in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 28 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Pavlof Volcano Seismicity 55.5 55 N 30 0 0 0 0 ...Pavlof Sister PV6a PN7Aa L a ...Pavlof aPS1A t i ~ 55'N 24 V t 55.4 0 0 u 0 0 d Hag~e~ aPW e 0& aPS4A a HAG 55 N 18 5km 55.3 0 10 20 162'W 06 161'W54 161'W42 Depth (km) Mag. Symb. Size -5 0 • 0 0 8 0 1 0 E 2 0 6 5 ~ 3 0 g. 10 0 0 4 0 0 0 15 5 0 20 -162.1 -162.0 -161.9 -161.8 -161.7 Longitude -5 ,, , , , 0 0 0 0 ··0· E 6 51- ~ 0 g. 10 0 0 0 15 ,, , , , , 20 Jan-2008 Mar Apr May Jun Jul Aug Sep ... Oct Nov Dec 20 Date Figure A16. Summary plots of earthquakes located near Pavlof Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 29 Mount Dutton Seismicity SS"N 14 55.22 o rIO ...Dutton 0 5518 '\ 0 00 SS"N 10 0 oog l 0 00 , ~o r 0 0 0 DTN t 0 i 55,14 0 t 0 0 0 "d e D DT1 SS"N 06 55.10 KIng Cove 5'km ~ 5506 0 10 2C 162 W 27 162 W 21 162 W 15 162"W 09 Depth (km) -, Mag. Symb. Size 0 0 • 0 o.ile 0 1 0 0 00 0 [ , 00 0 2 0 0 0 < 0 3 0 !IO 4 0 5 0 20" -162.4 -162.3 -162.2 Longitude -, 0 d e- , 'adO 0 < • "!IO 0 20" Jan-2GOa Me< A,. M', J"" J,' A"9 '" "" N~ "'" Date Figure A17. This summary plot shows earthquakes located near Mount Dutton in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. 30 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Unimak Island Seismicity 55.0 a ISNN Roundlop t'Sha~di ~ WTUG Iliano,s a k'v. L 54 B oo~ V¥~.I~K a o V I ~o t ISLZ e i go o ~ o~ I Fisher Caldera 0 BHPKO u Pogromni Cape Lazare. d 546 ~ e Westdahl~ 0" 0 0 54 N 30 -:0 o 20 km 54.4 0 0 0 10 20 164 W 30 164 W 00 163 W 30 Depth (km) Mag. Symb. Size -5 0 q, 0 • o . II . .. 1 0 0 'oW>e 0 0 WIlD 2 0 I 5 00 5 • 3 0 at 10 0 0 Ole o i~ 4 0 0 o 0 15 0 0 5 0 20 -164.8 -164.4 -164.0 T", !1M.6 T Longitude -5 q,o o 0 0 ·S·o .eo··· E 8 e 6 5 , ""g. 10 0 0 o 01 0 0 0 '00 15 0 0 0 20 Jan-200B Mar Apr ay Jun Jul Aug Sep Oct Nov Dec Dale Figure A18. Summary plots of earthquakes located near Unimak Island in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 31 Shishaldin Volcano Seismicity 54 N 51 54.S5 ISNN D SSLN D o 54.S0 o o o o o SSBA o~ D o 0 00 L 0 SSLWD #o 8 ~ "Oj~O0' o o CO v 54 N 45 • i 5475."~, o ~o. 0 S isRaj9in V I 010 0 v 0 o o o 0 0 0 u 0 0 8b o d 0 e 0 0 00 o 0 ssts 54.90 54 N 39 5km 54.65 0 10 20 164'W 00' 163°W 48 Depth (km) Mag. Symb. Size a • 1 0 2 0 3 0 4 0 15 5 0 20L-~-~--~-~--~-~----'--'r-~--V~ -164.1 -164.0 -163.9 , -163.S' Y Longitude lb O o 8 0 ..0 .. I 5 £; g. 10 o 15 20 V'lr'-____'__L....l'____'____'____'_____'____'___~L.L---'-----'----'----L--'---L....l-----'---'----'-----'----'----'---.L.....L----'-----'----'----'-----'---.L....JL....J Jan-200S Mar Apr YMay Jun Jul Aug Sep Oct Nov Dec Dale Figure A19. Summary plots of earthquakes located near Shishaldin Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 32 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Figure A20. Summary plots of earthquakes located near Westdahl Peak in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. Appendix A 33 Akutan Volcano Seismicity 54.3 r-~--~-___ 54°N 15 0 0 AKGGa HSB 54.2 a L a 0 o L~A. .~~LV 0 t 0 i 0 54 N 09 Akuta~ & a AKT t AKRBa ~ ~ V u d .\ o 0 • a °AKsa e o 0 AHB 54.1 AKM°cf aZRO 0 0 0 54 N 03 19 km 54.0 0 10 20 166 W 06 165°W 54 165 W 42 Depth (km) Mag. Symb. Size -5 • • 9 • 0 ...~. 1 0 E 00'1/' -5 0 • • 1 ... ,. • 8t. 0 o. ei ·11· 0 E o eo Ilfjf 0 .0··0& 0 ~ Sf- Y lJ 0 0 ~ '8!l 0 g. 10 0 0 0 • 15 f- 0 0 0 ~ ,,, . ,, 20 Jan-200B MarT Apr May Jun Jul AU9 Sep Oct Nov Dec Date Figure A21. Summary plots of earthquakes located near Akutan Peak in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 34 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Makushin Volcano Seismicity 54 N 00 54.0 aMTBIl o MCIRa 00 0 lib c • 0 0 0 , • 0 o a MSW • DuicH 53 N 54 L 53.9 Mak\)shin .:-.1 cf a Harbor· a ~ I o 0 V "-oCllL.dl J!'NPJ i o .. 0-';'- '0" 0 & I a u MSOMa 0 aMREP 0 d l' 53.8 MGOD e o 0 o 10 km o o 53 N 42 o 53.7 o o _On o 10 20 167 W 06 166 W 54 166 W 42 166 W 30 Depth (km) Mag. Symb. Size -5r-~--~--~-~--~--~--~------n o a o o . ,,0 0 .8cl .~. ·0 1 o 2 ~ 5 ~~~ol' 00 o .c o 3 o g. 10 ·cP~011" o~ 6' ~o~ o 4 o 15 5 o 20 L---'-__-UJ" __--'---'l7-~__~__'__"o'______"______" -167.2 -167.0 y -166.8 -166.6 Longitude -5 rT--,---,-~~,--r~,~~'--rT~--'--'-----'-'--,ro,-o-,---,--,-'''-,--,,,r-r-,--,-~,,r,--,'----' O~ . '0'" .. O' ... , ... , 0 .. (btl 0 :[ 5 0 o 00 o 8 I %(18' 0 0 If 0 .c ~ O~ 08~~ Et ~ 10 o l5'0 9 1)0 o o o 15 20 LJ.--'----L---'----'----'---L--'---'--'---.L.J""-'-1!L.L--'---'-----'----'---L-L----.J---L_'",10--,---,----,---'-'--JL--'-----'---'----'---.J'L-'---''------' Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Dale Figure A22. Summary plots of earthquakes located near Makushin Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. Appendix A 35 Umnak Island Seismicity 53.6 OKREa 53'N 30 OKl~ OKAK • keone D a CD 53.4 ~o. Okmok Con OKTlY' • OS 0 .0 0 ~ 0 53 N 18 L a o~ t i 53.2 0 00 t Mt Recheshnoii u , d Mt Vsevidof'" e 53 N 06 53.0 • Nikolski- 10 km 52 N 54 - 0 10 20 168'W 50 168'W 30 168'W10 16iw 50 Depth (km) Mag. Symb. Size -5 0 0 0 1 0 E 2 0 6 5 '9 .ci10 3 0 0 4 0 15 5 0 0 0 20 -169.0 -168.6 -168.4 -167.8 Longitude -5 0 0 08- CD 0 0 0 00 •• • a o~o ~ 0 E 0 o~ 00 0 6 5 0 fr llO 0 8 .c " 0 ° 0 10 0 0 o o oj. g. 0 0 ~ 0 0 0 0 15 0 0 20 01-Jan-2008 Mar Apr May JUl JLI Aug Sep ad Nov Dec 20 Date Figure A23. Summary plots of earthquakes located on Umnak Island in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. 36 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Northern Atka Island Seismicity 52 N 27 o o KONV¥ KONE • a 52.4 g "'Korovin KOWBI ClIo o KOKV o' aK0SE v • .OV"""t/ CID 0 KOKLa 0 0Mt Kliuchef L ; ,.. a o v t 52.3 a o i t , ,0 KOFP o 52 N 15 u o d o cP e 00 0 0 o o _Atka 0 0 o 52.2 o 00 OfJcP 00<90 o 0 CO 10 km 0 o ~ ~ 52.1 0 10 20 174'W 18 174'W 06 173 W 54 Depth (km) Mag. Symb. Size -5 o! • 0 0 • 0 0 •• 1 0 E 2 0 C- 5 O I '! ~ 0 $"67 00 0 9:» 0 3 0 g. 10 0 0 0 °8;) 4 0 0 0 15 0 0 5 0 20 -174.4 -174.3 -174.2 -174.1 -174.0 -1f3.9 Longitude -5 , , , 0 o. 0 .- 0 • E 0 • 0° o 8--... c- 5 (J 0 • ~ 0 0 0 0 ~ 10 ° 0 0 ~ 0 0 0 0 15 0 0 20 Jan-200B Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A24. Summary plots of earthquakes located near Korovin Volcano and Mount Kliuchef in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. Appendix A 37 Middle Andreanof Island Seismicity 52.2 52 N 10 • o 0 v r.o o ~ 0 • I • o Adagdak 0 0 • 52.0 • 0 0 ~bAG GSIGa ' ... .. It v L o a t 51 N 50 i t 51.8 1° u : d e o 51.6 0 V 20 km 51.4 , 0 10 20 177'W20 176 W 40 176'W 00 Depth (km) Mag. Symb. Size -5 0000 0 ... • 0 • 1 0 l" • 2 0 ~g.1 • ° 3 0 0 4 0 8 0 0 0 5 0 0 -176.8 -176.4 -176.0 Longitude -5 0 .. 00 000 0 oG.. ° • 0 0 ~ \ 0 • 5 0 -0) 0 • ~ • ~~. ° 0°11 '0 g. 10 0 o " 00 80 0 o ° 0 0 it' iO 8' i~ 0 15 0 8 0 00 0 0 olil 8' 0 0 20 Jan-2008 Mar Apr May Jun Jul Aug Sep Oct ov Dec Date Figure A25. Summary plots of earthquakes located in the Middle Andreanof Islands in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers and solid squares are used to show other points of interest. See appendix B for station information. 38 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Great Sitkin Volcano Seismicity 52.12 52 N 06 GSSP • • D DGSTR • 0 6 " :qreat Sitkin L 52.08 9 • .• a • • .' 0 i 0 52°N 04 • . t • ., i ~ GSTDo • t • u d , • • • DGSMY e 52.04 • 52 N 02 GSCKo • • 52 N 00 52.00 5km ° 0 10 20 176 W 12 176 W 06 176 W 00 Depth (km) Mag. Symb. Size -5 • .. • 0" 0 • 0 1 0 E ~ • e. 5 .. • 2 0 .c 0 3 0 g. 10 • 0 4 0 15 5 0 20 -176.2 -176.1 -176.0 Longitude -5 .. • • • • 0 "00 • 0 E \ • e. 5 • • .c 0 • -g. 10 • 0 15 20 Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A26. Summary plots of earthquakes located near Great Sitkin Volcano in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 39 51 0 N 58' .-_...... K_a..,n...a:::,a_V_o_lc_a9 ...n_o_S_e_is_m..,i_c-'iIY:...... _---. o o .-o o o 51.94 • o oKI~C 0 0 0 0 0 Kanaga o O 00 V ... e> 0 0 0 ~~ r:P 0 8 KICrv,o 0 0 o • o 0 0 o 0 0 0 • o 0 o 0 rP o L 0 0 0 51°N 54' O~~ 0 . ~ 0 I oKIRH 0 0 a 51.90 Po ~O Q90 00 ~oo 0. t o ~OO. :'f,°fllOI~ 0 i ~~ t _~ 0 008 o8~. u g 0 ~ COO 0 ~Cb 0 d 01 0 e 51.86 o 0 0 0 o 0 0 0 .oKIWB o o 0 0 0 ~ 0 0 0 o ...8i o 51 N 50 0 o • 0 0 o· o 0 5km 51.82 0 o ~~ 0 o 0 ~ 0 0 o 10 20 17iw 15 17iw09 • Depth (km) Mag. Symb. Size "'_iieCitcle;oe;IIiiIiii);...-oa---.~----aO«);~ -5i...... 0 .o~ oo-.. 00 «Do 0 • o -v. .0 .. . _ 0 0 0 0 1 0 0 2 0 g 5~' 0 ~c:8. ~~l 0 'lP 0 0 " .c 0 Oo~ otP 0 3 0 g. 10 0 ~ ~. 0 00 0 O 4 0 ~o 0 o 0 15 5 15 0 0 0 0 20L-_...:°:L--V--~---~---~---~--' -177.25 • -177.20 -177.15 -177.10 -177.05 Longitude ,-r-rtiililili_~W-'---'OO'-----'---'---''C~-'--'-'----'---'---'1, ' , -5i'---'--,---r--,-,-,---, 00 00 'C> o ~ 5~ ~~000 0 o 00~ ·0 0 .c 0 0 r 8 0 g. 10 ~ ~O o 0 Cl 0 0 0 0 0 15 (100 0 20 L.L--'---'-...L...L.L...L..L'-'----'--L-L.L--'-.::.L...L...L.L...L...l----.JL.L--'---'--'---.L....L...L...l-v'--'----'----'-.L...-'----J0 Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec 20 Date Figure A27. Summary plots of earthquakes located near Kanaga Volcano in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 40 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Western Andreanof Island Seismicity 0 0 52'N 00 52.0 0 Tanaga... Vo 0 Takawanghib... 51 N 48 0 L V a t i 0 0 t ~ 0 0 51 N 36 'VO u d GAKla 0 e 0 0 0 cP ~ . 51.4 51 N 24 -10 km 0 10 20 178'W 50 178'W 30 178'W 10 17iw 50 Depth (km) Mag. Symb. Size -5 0 • 1 0 00 0 2 0 0 Q) 3 0 0 0 0 0 0 rI 0 00 4 0 0 o 0 5 ~O 0 0 0 20 0 -178.8 -178.4 -178.0 Longitude -5 "----,---,--,-,--,,,----,----,--,---,------,-,----,----,--,---,------,---,---,----,-,--r-;,,----,---,-,--,r-;-,----,---,-,--,-----, o o I 5 0 ~ a: o •0 g. 10 o o Figure A28. Summary plots of earthquakes located in the Western Andreanof Islands in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 41 Tanaga Volcano Seismicity 51.94 51 N 56 TANG a 51.90 Tanaga A L Takawangha A a t i 51 oN 52 a t 51.86 TACS u d 0 0 e • D TASE 51.82 5km 51 N 48 0 0 0 0 10 20 178 W 15 178 W Og 178 W 03 Depth (km) Mag. Symb. Size -5 0 • 0 1 0 0 E 0 2 0 "'- 5 .c 3 0 ~ 10 0 4 0 15 5 0 20 -178.25 -178.20 -178.15 -178.10 -178.05 Longitude -5 0 E 0 0 5 "'-.c ~ 10 0 15 20 Jan-2008 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date Figure A29. Summary plots of earthquake located near Tanaga Volcano in 2008. Most earthquakes associated with the Tanaga volcanic center do not plot on this figure but to the east as seen on figure A28. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. 42 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Mount Gareloi Seismicity 51 N 52 o o 51.84 V 0 0 GANO a aG:<\NE 0 0 00 0 o 0 L '0 00 d:J 0 0 a 0 00 0 .ooceo 0 51 N 48 I 51.80 CO Gareloi i ~ 0 I 0 0 • aGAEA u GASWa 0 d 0 e aGAllA 51.76 51'N 44 5km 51.72 0 10 20 178'W 54 178'W 48 178'W 42 Depth (km) Mag. Symb. Size -5 0 • 0 1 0 E 2 0 6 5 0 0 0 0 ~ CJl ~O 3 0 g. 10 o·~OO o 0 0 0 4 0 0 15 0 5 0 20 -178.9 -178.8 • -178.7 Longitude -5 ,,, , , , , 0 E 6 5 8 0 ~ 0 0 • OOfO <»0 g. 10 0 0 o~ 0 0 0 0 15 0 ,, , 20 Jan-2008 Mar Apr May Jun Jut Aug Sep Oct Nov Dec Dale Figure A30. Summary plots of earthquakes located near Mount Gareloi in 2008. Open circles show hypocenter locations shallower than 20 km and open triangles indicate times of hypocenters with depths of 20 km and deeper. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix A 43 Semisopochnoi Island Seismicity 52 oN 02 0 0 aCEAP 52.00 .... Anvil Pk ° a CETU 0 51 N 58 0 CEPEa L 00 a t 51.95 0 0 o. .0 0 0 i Cerberut4 •• t aCERB Ragged Top "0~ 0 0 u 00 '" d ~ • 0 e CESW Dq:RA 51 °N 54 a Sugarloaf", 51.90 00 o 0 0 5km 0 51.85 0 10 20 179 °E 33 179 °E 39 179 °E 45 Depth (km) Mag. Symb. Size -5 0 0 0 1 0 0 E 0 2 0 6 5 • o 0 c:I'Q>•• <= 0 3 0 ~ o 00 0 10 0 4 0 0 0 0 15 5 0 0 20 179.50 179.55 179.60 179.65 179.70 179.75 Longitude -5 , , ,,, 0 E 0 0 5f- 0 6 0 Little Sitkin Volcano Seismicity ..... o o o , 52 NOD 8,-"- . .°0 52.00 .0 Q. o 0 00 d' 0 0 0 0 '0 •• ... 0 00 •• \T 0 0 0 00 00 • ~ 0 0 0 0 LSNIlII • o· 0 .o.-~.. 00 oa." • 00 oct-iol "pr.~ _0 00 • 0 8 CD 0 nco"o •• ~kin' L 51.96 o 0 00 0 ." LiMle ...•• LSPA/I o , ••• • 0 • 0 a o o aLSS'& _ 0 t ". 000 ft"G o 0 i o o 0 • • 0 o. t o o • aLSSE u 51 N 56 • d o o • o o e 51.92 o o o o 5km 51.88 L-~__~__-..J o 10 20 178°E30 178 °E 36 Depth (km) Mag. Symb. Size -5 c-----,------,------,------r----, o • • o • 1 o 2 o o 3 o 4 o 15 5 o o 20 L- -'--- ~ --'-- ~_~ 178.45 178.50 178.55 178.60 Longitude - 5 r-r-,----,-,-,---,---,-,---,---r-,----,----,---.,-r-,--,-,----,-,-,--,-,--,.,-,--r-c--,r-,--,-'---,-'---'--"-'--'-'-----' o y • 0 o 5~ II ;[ • .c o • 5i- 10ro o 15 o o 20 L--'----'----'--'-L_~'L--'--,~--'--_'____'___'____'___"_L_..J----'----'-L----'_"_,'____-'---'___L-'L--'_ _'___'--'---'---'____"_L_..J----' Jan-2008 Mar Apr May Jun Jut Aug Sep Oct Nov Dec Date Figure A32. Summary plots of earthquakes located near Little Sitkin Volcano in 2008. Open circles show hypocenter locations shallower than 20 km. Hypocenter symbols are scaled with magnitude. Permanent seismograph stations are shown by open squares and labeled by station code. Solid triangles are used to show volcanic centers. See appendix B for station information. Appendix B 45 Appendix B. Parameters for AVO Seismograph Stations in 2008. This list includes station parameters for seismograph stations operated by the Alaska Earthquake Information Center (AEIC) and the West Coast-Alaska Tsunami Warning Center (WC-ATWC) that were used to locate earthquakes in the AVO catalog. The open date is the date that data were first recorded and the close date is the date that recording was stopped. Discounting temporary data outages, date is available for each listed station between the open and close date. Stations still in operation are indicated by a dash in the close date column. Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Akutan Peak subnet (12 stations – 26 components) AHB 54 06.916 -165 48.943 447 L4 1996/07/24 - AKBB3 54 05.905 -165 55.907 310 CMG-6TD 2005/07/05 - AKGG3 54 11.930 -165 59.495 326 CMG-6TD 2003/06/27 - AKLV3 54 09.762 -165 57.336 551 CMG-6TD 2003/07/02 - AKMO3 54 05.471 -166 00.634 277 CMG-6TD 2003/06/25 - AKRB3 54 07.803 -166 04.125 334 CMG-6TD 2003/06/29 - AKS3 54 06.624 -165 41.803 213 L22 1996/07/24 - AKT3 54 08.15 -165 46.2 12 CMG-40T 1996/03/18 - AKV 54 07.571 -165 57.763 863 L4 1996/07/24 - HSB 54 11.205 -165 54.743 497 L4 1996/07/24 - LVA 54 09.654 -166 02.025 457 L4 1996/07/24 - ZRO 54 05.494 -165 58.678 446 L4 1996/07/24 - Aniakchak Crater subnet (6 stations – 8 components) ANNE 56 54.763 -158 03.534 705 L4 1997/07/18 - ANNW 56 57.986 -158 12.895 816 L4 1997/07/18 - ANON3 56 55.188 -158 10.293 445 L22 2000/07/10 - ANPB 56 48.141 -158 16.847 658 L4 1997/07/18 - ANPK 56 50.499 -158 07.572 972 L4 1997/07/18 - AZAC 56 53.727 -158 13.841 1,057 L4 2003/07/12 - Augustine Volcano subnet (9 stations – 18 components) AU223 59 22.247 -153 21.301 105 SM 2007/09/01 - AUE* 59 22.308 -153 22.504 168 S13 1980/10/29 - AUH 59 21.833 -153 26.591 890 S13 1978/12/01 - AUI3 59 20.11 -153 25.66 293 S13 1978/04/06 - AUL 59 22.937 -153 26.142 360 S13 1980/10/29 - AUL3 59 22.937 -153 26.142 360 CMG-6TD 1997/08/27 - AUNW* 59 22.694 -153 28.609 160 L4 2007/03/15 - AUP 59 21.805 -153 25.210 1,033 S13 1977/09/22 - AUSE 59 20.481 -153 23.850 152 L4 2006/02/03 - AUW 59 22.205 -153 28.249 276 S13 1976/10/17 - 46 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2007 Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Mount Cerberus Subnet (6 stations - 8 components) CEAP 52 00.146 179 34.667 244 L4 2005/09/17 - CEPE 51 57.949 179 38.950 335 L4 2005/09/17 - CERA 51 54.419 179 41.074 305 L4 2005/09/26 - CERB3 51 55.886 179 37.783 305 L4-3D 2005/09/18 - CESW 51 54.060 179 33.800 238 L4 2005/09/18 - CETU 51 57.965 179 29.651 335 L4 2005/09/22 - Mount Dutton subnet (5 stations - 5 components) BLDY 55 11.670 -162 47.018 259 L4 1996/07/11 - DOL 55 08.976 -161 51.702 439 L4 1996/07/11 - DRR3 54 58.014 -162 15.665 457 L4 1996/07/11 - DT1 55 06.427 -162 16.859 198 L4 1991/06/21 - DTN 55 08.744 -162 15.419 396 S13 1988/07/16 - Fourpeaked subnet (4 stations - 7 components) CDD 58 55.771 -153 38.558 622 S13 1981/08/17 - FONW* 58 50.086 -153 55.102 905 L-4 2007/10/19 - FOPK* 58 45.480 -153 28.433 546 L4 2007/09/25 - FOSS* 58 47.965 -153 41.699 1268 L-4 2007/10/10 - Gareloi Volcano subnet (6 stations - 8 components) GAEA 51 46.980 -178 44.810 326 L4 2003/08/30 - GAKI 51 33.267 -178 48.725 99 L4 2003/09/01 - GALA 51 45.704 -178 46.292 315 L4 2003/08/30 - GANE 51 49.135 -178 46.603 322 L4 2003/09/02 - GANO 51 49.220 -178 48.230 451 L4 2003/09/02 - GASW3 51 46.731 -178 51.276 248 L22 2003/08/30 - Great Sitkin Volcano subnet (6 stations - 8 components) GSCK 52 00.712 -176 09.718 384 L4 1999/09/15 - GSIG 51 59.181 -175 55.502 407 L4 1999/09/03 - GSMY 52 02.594 -176 03.376 418 L4 1999/09/03 - GSSP 52 05.566 -176 10.541 295 L4 1999/09/15 - GSTD3 52 03.356 -176 08.685 873 L22 1999/09/03 - GSTR 52 05.655 -176 03.546 536 L4 1999/09/03 - Iliamna Volcano subnet (6 stations - 8 components) ILI 60 04.877 -152 57.502 771 L4 1987/09/15 - ILS 59 57.454 -153 04.083 1,125 S13 1996/08/28 - ILW 60 03.585 -153 08.222 1,646 S13 1994/09/09 - INE 60 03.630 -153 03.732 1,634 S13 1990/08/29 - IVE3 60 01.014 -153 00.981 1,173 S13,L22 1996/09/19 - IVS 60 00.55 -153 04.85 2,332 S13 1990/08/29 - Kanaga Volcano subnet (6 stations - 6 components) KICM 51 55.136 -177 11.718 183 L4 1999/09/15 - KIKV 51 52.730 -177 10.223 411 L4 1999/09/15 - KIMD 51 45.697 -177 14.093 183 L4 1999/09/15 - KINC 51 55.884 -177 07.657 198 L4 1999/09/15 - KIRH 51 53.976 -177 05.611 309 L4 1999/09/03 - KIWB 51 51.183 -177 09.049 244 L4 1999/09/03 - Appendix B 47 Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Katmai Volcanic Cluster subnet (20 stations - 30 components) ACH3 58 12.64 -155 19.56 960 L22 1996/07/25 - ANCK 58 11.93 -155 29.64 869 L4 1996/07/25 - CAHL 58 03.15 -155 18.09 807 L4 1996/07/25 - CNTC 58 15.87 -155 53.02 1,158 L4 1996/07/25 - KA01# 58 18.858 -155 05.870 810 CMT-6TD 2008/07/20 - KA02# 58 15.116 -155 09.119 999 CMT3-ESP 2008/07/20 - KA03# 58 15.611 -155 07.881 1, 015 CMT-6TD 2008/07/20 - KA04# 58 13.354 -155 08.650 994 CMT-6TD 2008/07/20 - KA05# 58 12.942 -155 05.083 935 CMT-6TD 2008/07/20 - KA06# 58 12.660 -155 01.144 1, 003 CMT-6TD 2008/07/20 - KA11# 58 17.006 -155 08.357 1, 098 CMT-6TD 2008/07/20 - KA12# 58 13.904 -155 16.001 884 CMT-6TD 2008/07/20 - KA13# 58 13.262 -155 11.507 899 CMT3-ESP 2008/07/20 - KA15# 58 11.573 -155 11.143 926 CMT-6TD 2008/07/20 - KA16# 58 10.800 -155 05.999 714 CMT-6TD 2008/07/20 - KABR 58 07.87 -154 58.15 884 L4 1998/08/12 - KABU3 58 16.225 -155 16.934 1,065 CMT-6TD 2004/08/01 - KAHC 58 38.94 -155 00.36 1,250 L4 1998/10/12 - KAHG 58 29.64 -154 32.78 923 L4 1998/10/12 - KAIC 58 29.10 -155 02.75 734 L4 1998/10/12 - KAKN3 58 17.819 -155 03.668 1,049 CMG-6TD 2004/08/01 - KAPH3 58 35.81 -154 20.81 907 L22 1998/10/12 - KARR 58 29.87 -154 42.20 610 L4 1998/10/12 - KAWH 58 23.02 -154 47.95 777 L4 1998/10/12 - KBM 58 16.50 -155 12.10 732 L4 1991/07/22 - KCE 58 14.60 -155 11.00 777 L4 1991/07/22 - KCG3 58 18.457 -155 06.684 762 L22 1988/08/01 - KEL 58 26.401 -155 44.442 975 L4 1988/08/01 - KJL 58 03.24 -155 34.39 792 L4 1996/07/25 - KVT 58 22.90 -155 17.70 457 L4 1988/08/01 - MGLS 58 08.06 -155 09.65 472 L4 1996/07/25 - Korovin Volcano subnet (7 stations - 9 components) KOFP 52 16.508 -174 05.832 662 L4 2004/07/02 - KOKL 52 19.393 -174 12.012 758 L4 2004/07/05 - KOKV3 52 21.685 -174 09.915 776 L22 2004/07/05 - KONE 52 23.611 -174 07.156 253 L4 2004/07/10 - KONW 52 23.790 -174 12.629 334 L4 2004/07/04 - KOSE 52 20.749 -174 02.909 625 L4 2004/07/07 - KOWE 52 21.940 -174 15.040 527 L4 2004/07/06 - Little Sitkin subnet (4 stations - 6 components) LSNW 51 58.232 178 31.011 290 L4 2005/09/30 - LSPA3 51 57.413 178 34.405 335 L4-3D 2005/09/30 - LSSA 51 56.973 178 30.793 549 L4 2005/09/28 - LSSE 51 55.993 178 34.139 335 L4 2005/09/27 - 48 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2007 Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Makushin Volcano subnet (7 stations - 9 components) MCIR 53 57.086 -166 53.529 800 L4 1996/07/25 - MGOD 53 47.683 -166 52.561 650 L4 1996/07/25 - MNAT 53 53.028 -166 41.016 397 L4 1996/07/25 - MREP 53 48.629 -166 44.736 785 L4 2002/01/01 - MSOM 53 48.978 -166 56.187 146 L4 1996/07/25 - MSW3 53 54.929 -166 47.186 418 L22 1996/07/25 - MTBL 53 58.136 -166 40.760 810 L4 1996/07/25 - Okmok Caldera subnet (12 stations - 18 components) OKAK 53 24.740 -168 21.465 165 L4 2005/07/11 - OKCD3R 53 25.818 -168 06.737 459 CMG-6TD 2003/01/09 2008/07/12 OKCE3 53 25.622 -168 09.858 515 CMG-6TD 2003/01/09 - OKCF 53 23.749 -168 08.175 685 L4 2003/01/09 - OKER 53 27.278 -168 02.960 956 L4 2003/01/09 - OKFG3 53 24.702 -167 54.568 201 CMG-6TD 2003/01/09 - OKID 53 28.645 -167 48.972 437 L4 2003/01/09 - OKRE 53 31.215 -168 09.846 422 L4 2003/01/09 - OKSO3 53 21.447 -168 09.591 460 CMG-6TD 2004/09/01 - OKSP 53 15.156 -168 17.431 608 L4 2003/01/09 - OKTU 53 23.035 -168 02.466 646 L4 2003/01/09 - OKWE 53 28.328 -168 14.388 445 L4 2003/01/09 - OKWR 53 26.084 -168 12.333 1,017 L4 2003/01/09 - Pavlof Volcano subnet (7 stations - 9 components) BLHA 55 42.276 -162 03.540 411 L4 1996/07/11 - HAG 55 19.068 -161 54.144 516 L4 1996/07/11 - PN7A 55 26.020 -161 59.713 838 L4 1996/07/11 - PS1A 55 25.254 -161 44.496 283 L4 1996/07/11 - PS4A 55 20.808 -161 51.276 322 L4 1996/07/11 - PV63 55 27.217 -161 55.112 747 L22 1996/07/11 - PV013R 55 26.391 -161 56.359 852 CMG-6TD 2008/09/23 2008/07/18 PV023R 55 24.413 -161 48.176 458 CMG-6TD 2008/09/22 2008/07/22 PV033R 55 22.274 -161 51.985 584 CMG-6TD 2008/09/24 2008/07/21 PVV 55 22.440 -161 47.396 173 L4 1996/07/11 - Mount Peulik subnet (7 stations - 9 components) PLBL 57 41.990 -156 49.131 461 L4 2004/08/01 - PLK1 57 48.114 -156 36.433 78 L4 2004/08/01 - PLK2 57 45.852 -156 19.458 401 L4 2004/08/01 - PLK33 57 41.320 -156 16.044 494 L22 2004/08/01 - PLK4 57 37.928 -156 21.464 1,031 L4 2004/08/01 - PLK5 57 59.864 -156 52.662 49 L4 2004/08/01 - PLWL 58 02.696 -156 20.479 585 L4 2004/08/01 - Redoubt Volcano subnet (7 stations - 12 components) DFR 60 35.514 -152 41.160 1,090 L4 1988/08/15 - NCT 60 33.789 -152 55.568 1,079 L4 1988/08/14 - RDN 60 31.377 -152 44.273 1,400 L4 1988/08/13 - RDT 60 34.394 -152 24.315 930 L4 1971/08/09 - RED3 60 25.192 -152 46.308 1,064 L4 1990/08/30 - REF3* 60 29.362 -152 41.500 1,801 L22 1992/07/27 - RSO 60 27.73 -152 45.23 1,921 L4 1990/03/01 - Appendix B 49 Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Shishaldin Volcano subnet (7 stations - 11 components) BRPK 54 38.730 -163 44.449 393 L4 1997/07/27 - ISNN 54 49.937 -163 46.706 466 L4 1997/07/27 - ISLZ 54 43.559 -163 42.663 466 L4 2008/08/17 - ISTKR 54 43.929 -163 42.376 704 L4 1997/07/27 2008/08/17 SSBA3 54 46.363 -164 07.470 766 CMG-6TD 2008/08/01 - SSLN 54 48.709 -163 59.756 637 L4 1997/07/27 - SSLS3 54 42.718 -163 59.926 817 L22 1997/07/27 - SSLW 54 46.307 -164 07.282 628 L4 1997/07/27 - Mount Spurr subnet (15 stations - 23 components) BGL 61 16.012 -152 23.340 1,127 L4 1989/08/13 - BKG 61 04.21 -152 15.76 1,009 L4 1991/07/01 - CGL 61 18.46 -152 00.40 1,082 L4 1981/09/22 - CKL 61 11.782 -152 20.268 1,281 L4 1989/08/05 - CKN 61 13.44 -152 10.89 735 L4 1991/08/19 - CKT 61 12.05 -152 12.37 975 L4 1992/09/16 - CP2 61 15.85 -152 14.51 1,981 L4 1992/10/23 - CRP3 61 16.02 -152 09.33 1,622 L4 1981/08/26 - NCG 61 24.22 -152 09.40 1,244 L4 1989/08/06 - SPBG3 61 15.583 -152 22.194 1,087 CMG-6TD 2004/09/09 - SPCG3 61 17.512 -152 01.228 1,329 CMG-6TD 2004/09/08 - SPCR3 61 12.051 -152 12.409 984 CMG-6TD 2004/09/08 - SPNW 61 20.826 -152 36.236 1,040 L4 2004/08/17 - SPU 61 10.90 -152 03.26 800 L4 1971/08/10 - SPWE 61 16.441 -152 33.410 1,233 L4 2004/08/18 - Tanaga Volcano subnet (6 stations - 8 components) TACS 51 51.792 -178 08.363 918 L4 2003/08/28 - TAFL 51 45.396 -177 53.867 186 L4 2003/08/28 - TAFP3 51 54.003 -177 58.997 440 L22 2003/08/27 - TANO 51 54.942 -178 07.249 269 L4 2003/08/24 - TAPA 51 48.932 -177 48.770 640 L4 2003/08/27 - TASE 51 50.099 -178 02.222 682 L4 2003/08/24 - Mount Veniaminof subnet (9 stations - 9 components) BPBC 56 35.383 -158 27.153 584 L4 2002/10/03 - VNFG 56 17.140 -159 33.066 1,068 L4 2002/02/06 - VNHG 56 13.267 -159 09.853 966 L4 2002/02/06 - VNKR 56 01.871 -159 22.068 620 L4 2002/02/06 - VNNF 56 17.022 -159 18.961 1,153 L4 2002/06/20 - VNSG 56 07.549 -159 05.121 761 L4 2002/02/06 - VNSS 56 13.600 -159 27.290 1,733 L4 2002/02/06 - VNSW 56 04.317 -159 33.508 716 L4 2002/06/20 - VNWF 56 09.104 -159 33.733 1,095 L4 2002/02/06 - 50 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2007 Station Latitude (N) Longitude (E) Elevation (m) Seismometer Open date Close date Westdahl Peak subnet (6 stations - 8 components) WEBT 54 35.468 -164 45.183 467 L4 2008/08/02 - WECS 54 31.853 -164 46.653 642 L4 2008/08/03 - WESE 54 28.389 -164 35.038 953 L4 1998/08/28 - WESN 54 34.620 -164 34.704 549 L4 1998/10/17 - WESP3 54 28.611 -164 43.277 937 L22 2008/07/31 - WESS3R 54 28.828 -164 43.333 908 L22 1998/08/28 2008/07/31 WFAR R 54 32.029 -164 46.567 640 L4 1998/08/28 2008/08/03 WPOG R 54 35.837 -164 44.606 445 L4 1998/10/17 2008/08/02 WTUG 54 50.847 -164 23.117 636 L4 1998/10/17 - Mount Wrangell subnet (4 stations - 6 components) WACK3 61 59.178 -144 19.703 2,280 L22 2000/07/31 - WANC 62 00.189 -144 4.195 4,190 L4 2000/07/31 - WASW 61 55.692 -144 10.346 2,196 L4 2001/08/03 - WAZA 62 04.506 -144 9.132 2,531 L4 2001/08/03 - AVO Regional stations (9 stations - 11 components) ADAG 51 58.812 -176 36.104 286 L4 1999/09/15 - AMKA3 51 22.70 179 18.11 116 Tri-40 2005/10/14 - BGM 59 23.56 -155 13.76 625 L4 1978/09/08 - BGR 60 45.45 -152 25.06 985 L4 1991/07/01 - ETKA 51 51.712 -176 24.351 290 L4 1999/09/15 - MMN 59 11.11 -154 20.20 442 S13 1981/08/22 - OPT 59 39.192 -153 13.796 634 S13 1974/00/00 - PDB 59 47.09 -154 11.37 360 L4 1978/09/09 - STLK 61 29.926 -151 49.963 945 L4 1997/09/01 - AEIC and WCATWC stations ADK 51 53.022 -176 41.064 116 STS-1 1966/01/01 - AKUT 54 8.112 -174 11.730 55 STS-2 2002/10/03 - ATKA 52 12.162 -174 11.730 55 CMG-3ESP 2002/10/03 - BAL 61 02.172 -142 20.652 1541 L4 1973/08/24 - BMR 60 58.092 -144 36.180 842 CMG-40T 1979/08/19 - CHGN 56 18.084 -159 24.852 16 L4 2004/10/20 - CUT 62 24.282 -150 16.164 168 L4 1986/07/18 - FALS 54 51.438 -163 24.930 46 CMG-3ESP 2002/06/19 - GLB 61 26.508 -143 48.630 853 L4 1973/08/25 - HOM 59 39.498 -151 38.592 198 L4 1981/01/01 - KDAK 57 46.968 -152 35.010 152 KS-54000 1997/06/09 - MENT 62 56.280 -143 43.164 702 L4 2004/10/20 - NIKH 52 58.386 -143 58.032 507 STS-2 2007/06/21 - NIKO 52 56.328 -168 52.002 80 CMG-3ESP 2002/11/22 - NKA 60 44.580 -151 14.274 100 L4 1971/09/13 - PAX 62 58.224 -145 28.056 1130 STS-2 1969/07/01 - PLR 61 35.532 -149 7.842 100 L4 1984/09/21 - SCM 61 50.004 -147 19.644 1039 S13 1966/06/01 - SDG 62 31.620 -145 32.598 625 S13 1986/01/01 - SKN 61 58.836 -151 31.752 603 STS-2 1972/08/09 - SLK 60 30.738 -150 13.254 655 L4 1984/07/30 - UNV 53 50.790 -166 30.120 67 CMG-3ESP 1999/02/19 - Appendix B 51 Station Codes: 3 Three-component station # Temporary broadband station in AVO-U-Wisconsin tomography project R Station removed in 2008 * Seismic station has a both a high-gain and low-gain vertical component. Seismometer Codes: CMG-40T Guralp CMG-40T three-component broadband seismometer CMG-6TD: Guralp CMG-6TD three-component broadband seismometer CMG-3ESP: Guralp CMG-3ESP three-component broadband seismometer L4, L4-3D: Mark Products L4 or L4-3D single-component short-period seismometer L22: Mark Products L22 three-component short-period seismometer S13: Teledyne Geotech S13 single-component short-period seismometer SM: Ref Tek 130-ANSS/02 strong motion seismometer STS-1: Streckeisen STS-1H/VBB broadband seismometer STS-2: Streckeisen STS-2 broadband seismometer Tri-40: Nanometrics Trillium 40 three-component broadband seismometer 52 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2007 This page left intentionally blank. Appendix C 53 Appendix C. Locations of the AVO Seismograph Stations in 2008. 61 "N 30 _STLK "'Spurr _ BGR 60 "N 30 "'Redoubt , "'"iamna PDS a 59 "N 30 BGM - "Augustine aMMN AFourpeaked I 59km I 5S"N 30 '-~__~__~__~_~__~---l " " " 154 WOO 1S2 WOO 150 WOO Figure C1. Regional AVO seismograph stations in Cook Inlet in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 54 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 62°N 20 ...... -- ..... Sanford.... Drum • .... WAZA • 1:1 I:I~WrangeU 62°N 00 WACK 1:1 WANC 1:1 WASW. Blackburn : .... 61 °N 40 20km I I ° 145°WOO 144°W 00 143 WOO Figure C2. AVO seismograph stations near Mount Wrangell in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 61°N 24 1:1 NCG SPNW 1:1 Spurr A I:ICGL SPWE aSPCG 1:1 BGL Crater Peak 1:1 "a I:ICRP SPBGI:I CP2 I:ICKN 61 N 12 CKLa aCKT SPCR aSPU a BKG 19 km 61°N OO· ...... __--'''--- ...... ''---__~ ° • 151 W 50 Figure C3. AVO seismograph stations near Mount Spurr in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 55 Figure C4. AVO seismograph stations near Redoubt Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. INE D III IlWD D ...Ihamna IVSa DIVE ILS• lO km 153·W 00 Figure C5. AVO seismograph stations near Iliamna Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 56 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 o 59 N 24 aAUL AUNWa AUE AU22 AUW a Augustine a a A 59 N 22 AUHa a AUP a AUSE 0 a 59 N 20 AUI 5km 0 59 N 18 0 0 0 153 W 33 153 W 27 153 W21 Figure C6. AVO seismograph stations near Augustine Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. CODa •Douglas FONWa FOSS a Fourpeaked & aFOPK & Kaguyak Crater 19 km I Figure C7. AVO seismograph stations near Fourpeaked Mountain in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 57 58 N 40 KAHCa aKAPH KARR KAICa a aKAHG KELa KAWH SleU~Kukak KVT a Denison • Griggs KABU KeG'" ... Snowy 58 N 20 a a KAKN aeNTe KBM a D...Katmai ACH KCEa ... Trident D ANCK .....• Mageik Martin a aKABR MGlS . KJL• CAHL• 58 N 00 29 km Figure C8. AVO seismograph stations near the Katmai volcanic cluster in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. aPLK5 ...Ukinrek Maars PLK1a SiN 48 PlK2 Mt Peulik'" a PlBLa aPLK3 PLK4111 AMI Ugashik SiN 36 Figure C9. AVO seismograph stations near the Mount Peulik in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 58 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 ANNW- ANOND DANNE .1931 Vent />ZAC- .Vent Mountain ANPK ANPB 5km 5B'N 4s'L-----~-.,.__-----~.,.__--.J 158"W 12' 158 "WOO Figure C10. AVO seismograph stations near Aniakchak Crater in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. VNFGa aVNNF VNSS aVNHG SB'N 12 - "Veniaminof VNW'" a aVNSG VNSIND VNKR 56"N 00 - JOkm I 159"W 40 159"W20 159'WOO Figure C11. AVO seismograph stations near Mount Veniaminof in 2008. Seismograph station BPBC is not shown and is located 70 km northeast of Mount Veniaminof. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 59 5S"N 15 Kupreanof... SS"N 4S a BLHA ...Dana "'Pavlof Emmons SS"N 1S BLDY .. a .. a DOL Dutton .. NAG frosty a DRR3 54"N 4S 50km 163'W 00 162'W 00 1S(W 00 160"W 00 Figure C12. Regional AVO seismograph stations on the western end of the Alaska Peninsula in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. ...Pavlof Sister PV6a PN7Aa ...Pavlof aPS1A ...Hague aPW aPS4A a HAG SS"N 18·L ~---!:~S:k~m:::!..._c_-.J 162"W OS 161'W S4 161"W 42 Figure C13. AVO seismograph stations near Pavlof Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 60 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 55N 14r-----~----~----~-. ...Outton DTN• aDn 55N 06 5km 162 'WD9 Figure C14. AVO seismograph stations near Mount Dutton in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 55N 10 .----~-~--~-~--~-~-.., ISNN• Shishaldin... Isanots~ ISLZ"lSTK 20 km 164"W 00 Figure C15. Regional AVO seismograph stations on Unimak Island in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 61 o 54 N 51 ISNN a SSLN a SSBA a SSLwa 54 N 45 • Shishaldin a SSLS 5km o 54 N 39 o o 164 W 00 163 W 48 Figure C16. AVO seismograph stations near Shishaldin Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 54 N 39 WPOG WEBT" WESN . Pogromni A a 54 N 33 rI' WFAR .. Faris Peak WECS _ • Westdahl WESS dl WESP aWESE . , 54 N 27 10 km Scotch Cap· Figure C17. AVO seismograph stations near Westdahl Peak in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 62 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 54°N 15 AKGG a HSB a LVA a aAKLV 54°N 09 ... Akutan AKT a AKRBa aAKV a a AKSa AKBB AHB a aZRO AKMO 54°N 03 10 km 166 W 06 165 W 54 165 W 42 Figure C18. AVO seismograph stations near Akutan Peak in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 54°N 00 Table Top-Wide Bay MTBL 'MJ a MCIR MSW a 53°N 54 Makushin ... a MNAT a MSOM aMREP 53°N 48 aMGOD 53 N 42 10 km I 16iw 06 Figure C19. AVO seismograph stations near Makushin Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 63 o 53 N 33 a OKRE OKW~ a OKER OKWR a OKCD OKAK OKCEf a... Cone 0 a a OKFG ConeAA a OKCF a OKTU , . o a 53 N 21 OKSO OKSP a 10 km 168 W 24 168 W 12 167 W 48 Figure C20. AVO seismograph stations near Okmok Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. OKCD was destroyed in the 2008 Okmok eruption. 52 N 27 KONW KONE a a ....Korovin KOWEa KOKVD aKOSE D ....Mt Kliuchef KOKL a KOFP 10 km Figure C21. AVO seismograph stations on Atka Island in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 64 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 52 N 10 Great Sitkin & ADAG; Adagdak Moffett & & Kanaga ETKA• KIMD• I 20km I Figure C22. Regional AVO seismograph stations around Adak Island in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 52"N OS GSSP a aGSTR "'Great Silkin 52"N 04 GSTDa aGSMY 52"N 02 GSCKD 52"N 00 5km . 17S"W 12 17S"WOS 176 WOO Figure C23. AVO seismograph stations near Great Sitkin Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 65 o 51 N 58 r---__------...... ------..----, Kanaga... aKINC KICMa o 51 N 54 aKIRH a KIKV a KIWB o 51 N 50 5km o o o 177 W 15 177 W 09 177 W 03 Figure C24. AVO seismograph stations near Kanaga Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Tanaga ...... aTAFP Takawangha T";PA Gareloi ... D GAKI a 178Ow SO 178 Ow 30 177 Ow SO Figure C25. Regional AVO seismograph stations around Tanaga Volcano and Mount Gareloi in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 66 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 lANa a ranaga· Takawangha.. 51N 52 a TACS lASE a 5km 51 N 48 178'W 15 178'W 03 Figure C26. AVO seismograph stations near Tanaga Volcano in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 51'N 52 r------, GANQ a aGANE Gareloi• aGAEA GASwa 5km 178'W 48 178 ·w 42 Figure C27. AVO seismograph stations near Mount Gareloi in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. Appendix C 67 52 oN 02 DCEAP Anvil Pk .... CITU • CEPE D Cerberus • DCERB Ragged Top .. CESW DCERA 51 oN 54 D Sugarloaf • Skm 179 oED' 179°E39 179 'E45 Figure C28. AVO seismograph stations on Semisopochnoi Island in 2008. Seismograph station AMKA is not shown and is located 65 km south-southwest of Mount Cerberus. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. LSNW 51 'N 58' • Little Silkin • LSPA• LSSA• LSSE• 5km 178 'E 30 178'E36 Figure C29. AVO seismograph stations on Little Sitkin Island in 2008. Permanent seismograph stations are shown by open squares. Closed triangles show volcanic centers. 68 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 This page left intentionally blank. Appendix D 69 Appendix D. Operational Status for AVO Stations in 2008. A solid bar indicates periods of time a station was operational based on station use plots and weekly checks. Dashed vertical lines show the beginning/end of each month. Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec , , , , , , , ACH :: : : :ACH ADAG :ADAG AHB :AHB AKBB ,'AKBB AKGG 'AKGG AKLV :AKLV AKMO :AKMO AKRB ;AKRB AKS ,'AKS AKT ,AKT AKV IAKV AMKA :AMKA ANCK ,ANCK ANNE ,ANNE ANNW ·ANNW ANON :ANON ANPB :ANPB ANPK :ANPK AU22 AU22 AUE AUE AUH IAUH AUI :AUI AULb :AULb AUL , AUL AUNW , AUNW AUP , IAUP AUSE: ;AUSE AUW , ;AUW AZAC , AZAC BGL - , BGL BGM ,BGM BGR , ~8GR BKG - ;BKG BLDY :BLDY BLHA , , 'BLHA BPBC ,- : BPBC BRPK - :BRPK CAHL ,CAHL COD -COD, 70 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec I I I I I II CEAP i; i CEAP CEPE : :-: ~: CEPE CERA CERA CERB CERB CETUCESW :=::;:=;:~=:;=;=~~=~=~=;:~=~ICETUCESW CGL CGL C~ C~ CKN CKN C~ C~ CNTC CNTC C~ C~ CRP , CRP DFR -', DFR DOL DOL DRR3 DRR3 DT1 Dn DTN DTN EKTA EKTA FONW FONW FOPK FOPK FOSS --+--I I FOSS GAEA ,GAEA GAKI : GAKI GALA - GALA GANE .... GANE GANO : GANO GASW : GASW GSCK ,GSCK GSIG 'GSIG GSMY : GSMY GSSP : GSSP GSTD , ,GSTD GSTR ~ : GSTR HAG , HAG HSB ,HSB III III ILS ILS ILW ILW INE INE ISLZ ISLZ ISNN ISNN ISTK ,' ISTK IVE --, IVE IVS ' IVS Appendix D 71 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec KABRKABU :======:..======KABRKABU KAHCKAHG :=~======KAHCKAHG KAIC KAIC KAKN KAKN KAPH KAPH KARR KARR KAWH KAWH KBM KBM KCE KCE KCG KCG KEL KEL KICM - KICM KIKV _ KIKV KIMD - KIMD KINC - KINC KIRH _ KIRH KIWB KIWB KJL KJL KOFP , KOFP KOKL KOKL KOKV KOKV KONE KONE KONW - KONW KOSE : , KOSE KOWE: : KOWE KVT ,' KVT LSNW , LSNW ~~ ,~~ LSSA ' LSSA LSSE : LSSE LVA LVA MCIR MCIR MGLS MGLS MOOD MOOD MMN MMN MNAT MNAT MREP MREP MSOM MSOM MSW MSW MTBL MTBL NCG NCG NCT NCT 72 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec OKCDOKAK :======:------OKAKOKCD OKCE 'OKCE OKCF OKCF OKER - OKER OKFG OKFG OKID - - - OKID OKRE OKRE OKSO OKSO OKSP OKSP OKTU OKTU OKWE OKWE O~R O~R OPT OPT PDB PDB PLBL PLBL PLK1 PLK1 PLK2 PLK2 PLK3 PLK3 PLK4 PLK4 PLKS PLKS PLWL PLWL PN7A PN7A PS1A PS1A PS4A PS4A PV6 .....;..... :PV6 PVV :PW RDN I "RDNII I ROT I -I ROT I II I RED.... .RED REF - 'REF RSO RSO SPBG SPBG SPCG 'SPCG SPCR SPCR SPNW SPNW SPU SPU SPWE SPWE SSBA SSBA SSLN SSLN SSLS SSLS SSLW SSLW STLK STLK Appendix D 73 Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec TACS TACS TAFL • - TAFL TAFp· -TAFP TANO· -TANO TAPA· TAPA TASE· -TASE VNFGVNHG :======:::;=====VNFGVNHG VNKR VNKR VNNF VNNF VNSG VNSG VNSS VNSS VNSW- VNSW VNWF VNWF WACK - - WACK WANC WANC WASW WASW WAZA WAZA WEST WEST WECS WECS WESE WESE WESN - WESN WESP WESP WESS WESS WFAR WFAR WPOG, WPOG WTUG, WTUG ZRO ZRO 74 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 This page left intentionally blank. Appendix E 75 Appendix E. Seismic Velocity Models Used in Locating the Earthquakes in 2008. Following the name of each velocity model is a list of volcano subnetworks for which the model is used. Depths are referenced to sea level, with negative values reflecting height above sea level. Cylindrical Model Parameters (Latitude and Longitude are the center of the model). Latitude Longitude Radius Top Bottom Velocity Model (°N) (°E) (km) (km) (km) Spurr 61.60 -152.40 20 -3 50 Spurr 61.47 -152.33 20 -3 50 Spurr 61.33 -152.25 20 -3 50 Spurr 61.17 -152.35 20 -3 50 Spurr 61.00 -152.45 20 -3 50 Redoubt 60.83 -152.55 20 -3 50 Redoubt 60.66 -152.66 20 -3 50 Redoubt 60.49 -152.75 20 -3 50 Redoubt 60.34 -152.86 20 -3 50 Iliamna 60.03 -153.09 20 -3 50 Augustine 59.36 -153.42 20 -3 50 Katmai 58.17 -155.35 20 -3 50 Katmai 58.29 -154.86 20 -3 50 Katmai 58.35 -155.09 20 -3 50 Katmai 58.43 -154.38 20 -3 50 Veniaminof 56.18 -159.38 30 -3 50 Cold Bay 55.42 -161.89 20 -3 50 Cold Bay 55.18 -162.27 20 -3 50 Cold Bay 54.76 -163.97 30 -3 50 Westdahl 54.52 -164.65 20 -3 50 Akutan 54.15 -165.97 20 -3 50 Okmok 53.40 -176.13 20 -3 50 Andreanof 52.08 -176.13 20 -3 50 Andreanof 51.93 -176.75 20 -3 50 Andreanof 51.92 -177.17 20 -3 50 Tanaga 51.89 -178.15 20 -3 50 76 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Regional Velocity Model (Fogleman and others, 1993). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 5.3 -3.0 1.78 2 5.6 4.0 1.78 3 6.2 10.0 1.78 4 6.9 15.0 1.78 5 7.4 20.0 1.78 6 7.7 35.0 1.78 7 7.9 33.0 1.78 8 8.1 47.0 1.78 9 8.3 65.0 1.78 Akutan Velocity Model (Power and others, 1996). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 2.30 +0.37 km/sec for each km of depth -3.0 1.80 2 6.30 7.0 1.80 Andreanof Velocity Model (Toth and Kisslinger, 1984). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 3.50 -3.0 1.73 2 3.88 -2.8 1.73 3 4.25 -2.6 1.73 4 4.62 -2.4 1.73 5 5.00 -2.2 1.73 6 5.50 -2.0 1.73 7 5.62 -1.0 1.73 8 5.74 0.0 1.73 9 5.86 1.0 1.73 10 5.98 2.0 1.73 11 6.10 3.0 1.73 12 6.60 4.0 1.73 13 6.68 5.0 1.73 14 6.80 8.0 1.73 15 6.92 11.0 1.73 16 7.04 14.0 1.73 17 7.16 17.0 1.73 18 7.28 20.0 1.73 19 7.85 23.0 1.73 20 8.05 37.0 1.73 Appendix E 77 Augustine Velocity Model (Power, 1988). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 2.3 -3.0 1.80 2 2.6 -0.7 1.80 3 3.4 0.0 1.80 4 5.1 1.0 1.80 5 6.3 9.0 1.78 6 8.0 44.0 1.78 Cold Bay Velocity Model (McNutt and Jacob, 1986). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 3.05 -3.00 1.78 2 3.44 0.00 1.78 3 5.56 1.79 1.78 4 6.06 3.65 1.78 5 6.72 10.18 1.78 6 7.61 22.63 1.78 7 7.90 38.51 1.78 Iliamna Velocity Model (Roman and others, 2001). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 4.8 -3.0 1.78 2 6.1 -1.6 1.78 3 6.2 1.7 1.78 4 6.3 2.9 1.78 5 6.4 3.1 1.78 6 7.1 16.5 1.78 78 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Katmai Velocity Model (Searcy, 2003). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 5.05 -3.0 1.78 2 5.10 1.0 1.78 3 5.41 2.0 1.78 4 5.49 3.0 1.78 5 5.65 4.0 1.78 6 5.67 5.0 1.78 7 5.69 6.0 1.78 8 5.76 7.0 1.78 9 5.80 8.0 1.78 10 6.00 9.0 1.78 11 6.04 10.0 1.78 12 6.08 12.0 1.78 13 6.30 15.0 1.78 14 6.73 20.0 1.78 15 7.54 25.0 1.78 16 7.78 33.0 1.78 Okmok Velocity Model (Searcy and Prejean, U.S. Geological Survey, written commun., 2009). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 3.830 -3.0 1.73 2 3.891 0.0 1.73 3 5.084 1.0 1.73 4 5.187 2.0 1.73 5 5.470 3.0 1.73 6 6.185 4.0 1.73 7 6.191 10.0 1.73 8 6.454 12.0 1.73 9 6.896 16.0 1.73 10 7.414 20.0 1.73 Redoubt Velocity Model (Lahr and others, 1994). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 2.90 -3.0 1.80 2 5.10 -1.7 1.80 3 6.40 1.5 1.72 4 7.00 17.0 1.78 Appendix E 79 Spurr Velocity Model (Jolly and others, 1994). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 5.1 -3.00 1.81 2 5.5 -2.00 1.81 3 6.3 5.25 1.74 4 7.2 27.25 1.78 Tanaga Velocity Model (Power, personal commun., 2005). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 4.0 -3.0 1.78 2 4.5 -1.2 1.78 3 5.0 0.0 1.78 4 5.6 4.0 1.78 5 6.9 10.0 1.78 6 7.2 15.0 1.78 7 7.8 20.0 1.78 8 8.1 33.0 1.78 Veniaminof Velocity Model (Sánchez, 2005). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 4.82 -3.0 1.73 2 5.23 4.0 1.88 3 5.23 10.0 1.38 4 6.49 15.0 1.65 5 6.52 20.0 1.51 6 8.18 25.0 1.89 7 8.21 33.0 1.90 8 8.21 47.0 1.80 9 8.30 65.0 1.78 Westdahl Velocity Model (Dixon and others, 2005). Layer number Vp (km/sec) Top of layer (km) Vp/Vs 1 3.03 -3.0 1.71 2 3.18 0.0 1.71 3 5.03 2.0 1.71 4 5.70 8.0 1.71 5 6.30 10.0 1.71 6 6.82 16.0 1.71 7 7.17 26.0 1.71 8 8.16 38.0 1.71 80 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 This page left intentionally blank. Appendix F 81 Appendix F. Location of Volcanic Zones Modeled Using Multiple Cylinders. 0AU9USline . .. G:50Urpeaked Figure F1. Volcanic zones for the Cook Inlet Volcanoes. Five overlapping cylinders model the Spurr volcanic zone. Four overlapping cylinders model the Redoubt volcanic zone. Single cylinders model the Iliamna, Augustine, and Fourpeaked volcanic zones. I 20 km I Figure F2. Volcanic zone for the Katmai volcanic cluster. The volcanic zone is modeled using four overlapping cylinders centered on Mount Martin, Mount Katmai, Mount Griggs, and Mount Steller. 82 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Kupreanof. 52 km 0 163°W 00 162°W 00' 161°W 00' 160 WOO' Figure F3. Volcanic zones for Pavlof Volcano and Mount Dutton. The volcanic zone is modeled using two overlapping cylinders centered on Mount Dutton and Pavlof Volcano. Kanaga• I 22km Figure F4. Volcanic zones in the Adak region. The volcanic zones are modeled using cylinders centered on Kanaga Volcano, Mount Moffet, and Great Sitkin Volcano. Appendix G 83 Appendix G. Previous Alaska Volcano Observatory Earthquake Catalogs. Earthquake catalog for 1989–present available from the USGS. 1989–90: Power, J.A., March, G.D., Lahr, J.C., Jolly, A.D., and Cruse, G.R., 1993, Catalog of earthquake hypocenters at Redoubt Volcano and Mount Spurr, Alaska: October 12, 1989 – December 31, 1990: U.S. Geological Survey Open-File Report 93-685-A, 57 p. URL: http://pubs.er.usgs.gov/usgspubs/ofr/ofr93685A 1991–93: Jolly, A.D., Power, J.A., Stihler, S.D., Rao, L.N., Davidson, G., Paskievitch, J., Estes, S., and Lahr, J.C., 1996, Catalog of earthquake hypocenters for Augustine, Redoubt, Iliamna, and Mount Spurr Volcanoes, Alaska: January 1, 1991 - December 31, 1993: U.S. Geological Survey Open- File Report 96-70, 90 p. URL: http://pubs.er.usgs.gov/usgspubs/ofr/ofr9670 1994–99: Jolly, A.D., Stihler, S.D., Power, J.A., Lahr, J.C., Paskievitch, J., Tytgat, G., Estes, S., Lockhart, A.B., Moran, S.C., McNutt, S.R., and Hammond, W.R., 2001, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1, 1994 - December 31, 1999: U.S. Geological Survey Open-File Report 01-189, 202 p. URL: http://geopubs.wr.usgs.gov/open-file/of01-189/ 2000–01: Dixon, J.P, Stihler, S.D., Power, J.A., Tytgat, G., Estes, S., Moran, S.C., Paskievitch, J., and McNutt, S.R., 2002, Catalog of Earthquake Hypocenters at Alaska Volcanoes: January 1, 2000 - December 31, 2001: U.S. Geological Survey Open-File Report 02-342, 56 p. URL: http://geopubs.wr.usgs.gov/open-file/of02-342/ 2002: Dixon, J.P., Stihler, S.D., Power, J.A., Tytgat, G., Moran, S.C., Sánchez, J.J., Estes, S., McNutt, S.R., and Paskievitch, J., 2003, Catalog of Earthquake Hypocenters at Alaska Volcanoes: January 1 - December 31, 2002: U.S. Geological Survey Open-File Report 03-267, 58 p. URL: http://geopubs.wr.usgs.gov/open-file/of03-267/ 2003: Dixon, J.P., Stihler, S.D., Power, J.A., Tytgat, G., Moran, S.C., Sánchez, J.J., Estes, S., McNutt, S.R., and Paskievitch, J., 2004, Catalog of Earthquake Hypocenters at Alaska Volcanoes: January 1 - December 31, 2003: U.S. Geological Survey Open-File Report 2004-1234, 59 p. URL: http://pubs.usgs.gov/of/2004/1234/ 2004: Dixon, J.P., Stihler, S.D., Power, J.A., Tytgat, G., Estes, S., Prejean, S., Sánchez, J.J., Sanches, R., McNutt, S.R., and Paskievitch, J., 2005, Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2004: U.S. Geological Survey Open-File Report 2005-1312, 74 p. URL: http://pubs.usgs.gov/of/2005/1312/ 2005: Dixon, J.P., Stihler, S.D., Power, J.A., Tytgat, G., Estes, S., and McNutt, S.R., 2007, Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2005: U.S. Geological Survey Open-File Report 2007-1264, 78 p. URL: http://pubs.usgs.gov/of/2007/1264/ 84 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 2006: Dixon, J.P., Stihler, S.D., Power, J.A., and Searcy, Cheryl, 2008, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1 through December 31, 2006: U.S. Geological Survey Data Series 326, 78 p. URL: http://pubs.usgs.gov/ds/326/pdf/ds326.pdf 2007: Dixon, J.P., Stihler, S.D., and Power, J.A., and Searcy, Cheryl, 2008, Catalog of earthquake hypocenters at Alaskan Volcanoes: January 1 through December 31, 2007: U.S. Geological Survey Data Series 367, 82 p. URL: http://pubs.usgs.gov/ds/367/pdf/ds367.pdf Appendix H 85 Appendix H. Selected Papers Published in 2008 Using Alaska Volcano Observatory Data. Pesicek, J.D., Thurber, C.H., DeShon, H.R., Prejean, S.G., and Zhang, H., 2008, Three-dimensional P-wave velocity structure and precise earthquake relocation at Great Sitkin Volcano, Alaska, 2008: Bulletin of the Seismological Society of America, v. 98, no. 5, p. 2428-2448. McNutt, S.R., and Nishimura, T., 2008, Volcanic tremor during eruptions: Temporal characteristics, scaling and estimates of vent radius: Journal of Volcanology and Geothermal Resources, v. 178, p. 10-18. Waythomas, C.F., Prejean, S.G., and McNutt, S.R., 2008, August-September, 2007 eruption of Pavlof Volcano, Alaska: Eos Transactions, American Geophysical Union, v. 89, no. 23, June 3, 2008. 86 Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008 Publishing support provided by the U.S. Geological Survey Publishing Network, Tacoma Publishing Service Center For more information concerning the research in this report, contact the Director, Alaska Science Center U.S. Geological Survey 4210 University Dr. Anchorage, Alaska 99508-4650 http://alaska.usgs.gov Dixon and Stihler—Catalog of Earthquake Hypocenters at Alaskan Volcanoes: January 1 through December 31, 2008—Data Series 467