ANNUAL TECHNICAL REPORT

USGS Joint Operating Agreement 01HQAG0011
"PACIFIC NORTHWEST SEISMOGRAPH NETWORK (PNSN) OPERATIONS"

SUMMARY
This is the 2001 annual technical report for USGS Joint Operating Agreement 01HQAG0011 "Pacific Northwest Seismograph Network (PNSN) Operations" This agreement covered network operations in western Washington and northern Oregon, routine data processing, and preparation of bulletins and reports. PNSN stations in southern and central Oregon are maintained by the University of Oregon under Cooperative Agreement 01HQAG0012 and this report also covers the work undertaken under that agreement. The objective of our work under this operating agreement was to gather seismic data, and to analyze and interpret them for use in evaluation of seismic and volcanic hazards in Washington and Oregon. This report includes an update on recent changes in our data acquisition and processing system, a review of station operations during 2001, an overview of our public information program, and a summary of 2001 seismicity.

Since 1984, we have issued quarterly bulletins for all of Washington and Oregon. These include catalogs of earthquakes and blasts located in Washington and Oregon, providing up-to-date coverage of seismic and volcanic activity. Appendix 1 contains quarterly bulletins covering 2001.

CURRENT INITIATIVES

Introduction

The PNSN is continuing the long process of upgrading operations. Upgrades include enhancement of the emergency information distribution system, installation of seismic sensors that can accurately capture the full range of earthquake amplitudes and frequencies, implementation of a data recording system that fully supports multi-component data, and near-real-time data exchange with neighboring networks.

CREST Stations

The USGS/NOAA CREST (Consolidated Reporting of EarthquakeS and Tsunamis) project is designed to improve NOAA's ability to assess the likelihood of a tsunami and issue timely warnings in the event of a west coast subduction earthquake. CREST calls for upgrades to regional networks to enable them to provide very rapid and reliable information to the Alaska and Pacific Tsunami Warning Centers. Installation of CREST stations began in 1998. In 2001, CREST Oregon stations were installed in Eugene, Tahkenitch, and Toledo. In Washington, stations were installed in Port Angeles, and near Forks, Washington. Two additional sites; at Megler, Washington and Mt. Hebo, Oregon; were installed during 2001 but telemetry was not yet functioning.

PNSN Strong Motion Program

Since 1996, the PNSN has installed digital strong-motion instruments. Most of these are in the Puget Sound Area, but stations are also being sited in other urban areas. In 2001, 23 new permanent (and 2 temporary) instruments were installed, bringing the total number of PNSN real-time strong-motion instruments to 70. Continuous data from these stations are sent to the PNSN via Internet or lease-line modem. Most of the strong-motion instruments (except CREST stations) also have internal memory and are configured to record internally if ground motions exceed a specified threshold. If continuous data transmission fails, the internally recorded data are still available via dial-up retrieval or site visit. Three additional dial-up stations in the Portland area are operated by the USGS.

PNSN RACE (Rapid Alerts for Cascadia Earthquakes) System

RACE is an earthquake notification system for emergency managers and others who need very rapid pager-based notification of earthquake activity. The RACE system is based on the CUBE system developed at Caltech for the Southern California Seismic Network. The RACE system is operating in approximately 10 emergency management and state agencies in Washington and Oregon.

EARTHWORM Progress Report

In 2001, scossa became our primary EARTHWORM computer, and milli was demoted to primary backup computer, while verme remained the secondary backup computer.

When one of our SUNWORM digitizers began to have problems in early 2001, we obtained an official EARTHWORM digitizer from the central EARTHWORM team. By the end of 2001, the complex wiring for pigia , the new Intel-based EARTHWORM digitizer running under Windows NT, was completed and pigia began digitizing data. Pigia will operate as an EARTHWORM node, exporting digitized data to verme. We are currently configuring the files that associate channel numbers with station and component names. Full integration of pigia into our data acquisition process is expected in the first quarter of 2002.

In mid-February a new earthquake magnitude calculator, localmag , was implemented as part of our routine earthworm system. It had been tested by its developer, Pete Lombard, using previously recorded PNSN data but calibration had not been completed. Thus, PNSN staff had only very brief training and minimal experience with localmag when the Nisqually earthquake occurred on Feb. 28. The initial magnitude estimates from localmag were available less than 15 minutes after the earthquake, and were very close to the final magnitude of 6.8. We continue to gather information on how localmag performs over a wider magnitude range.

During January and early February, Steve Malone gave a 6-week class on the PNSN EARTHWORM implementation. This class brought PNSN staff up-to-date on most of the critical features of our data acquisition system, and improved our ability to deal with operational problems, which worked out well in the Nisqually earthquake.

OPERATIONS

Seismometer Locations and Network Maintenance

Figure 1 shows seismograph stations operated by the PNSN at the end of 2001, when the PNSN EARTHWORM SYSTEM was digitally recording 439 channels of real-time or near-real-time seismic data. Stations available include a total of 149 short-period stations, 30 broad-band, and 73 strong-motion stations.

This contract (JOA 01HQAG0011) supports 99 short-period sites (some with multiple components) and operation of 70 strong motion and 18 broad-band stations. The supported stations cover much of western Washington and Oregon, including the volcanos of the central Cascades.

Additional stations funded by other contracts, or telemetered in real or near-real time from adjacent networks, are also used in event locations. Station Tables 1A-1C list the locations of various types of stations. Quarterly reports provide additional details of station operation. Quarterly reports from January 1, 2001 through December, 2001 are included as Appendix 1.

Aside from station outages, normal maintenance includes a visit to each site at least once every two years to replace batteries and do preventive maintenance. In addition seismometers must be replaced every 4-6 years. More than 30 radio telemetry relay sites are also maintained independently of the seismograph stations.

Table 1A lists short-period, mostly vertical-component stations used in locating seismic events in Washington and Oregon. The first column in the table gives the 3-letter station designator, followed by a symbol designating the funding agency; stations marked by a percent sign (%) were supported by USGS joint operating agreement 01-HQ-AG-0011. A plus (+) indicates support under Pacific Northwest National Laboratory, Battelle contract 259116-A-B3. Stations designated "#" are USGS-maintained stations recorded at the PNSN. Stations designated by letters are operated by other networks, and telemetered to the PNSN. "M" stations are received from the Montana Bureau of Mines and Geology, "C" stations from the Canadian Pacific Geoscience Center, "U" stations from the US Geological Survey (usually USNSN stations), "N" stations from the USGS Northern California Network, and "H" stations from the Hanford Reservation via the Pacific Northwest National Labs. Other designation indicate support from other sources. Additional columns give station north latitude and west longitude (in degrees, minutes and seconds), station elevation in km, and comments indicating landmarks for which stations were named.


TABLE 1A - Short-period Stations operated by the PNSN during the fourth quarter 2001
STA  F  LAT  LONG  EL  NAME
 ASR   %  46 09 09.9  121 36 01.6  1.357  Mt. Adams - Stagman Ridge
 AUG   %  45 44 10.0  121 40 50.0  0.865  Augspurger Mtn
 BBO   %  42 53 12.6  122 40 46.6  1.671  Butler Butte, Oregon
 BEN   1  46 31 12.0  119 43 18.0  0.335  W  PNNL station
 BHW   %  47 50 12.6  122 01 55.8  0.198  Bald Hill
 BLN   %  48 00 26.5  122 58 18.6  0.585  Blyn Mt.
 BOW   %  46 28 30.0  123 13 41.0  0.870  Boistfort Mt.
 BPO   %  44 39 06.9  121 41 19.2  1.957  Bald Peter, Oregon
 BRO   %  44 16 02.5  122 27 07.1  0.135  Big Rock Lookout, Oregon
 BRV   +  46 29 07.2  119 59 28.2  0.920  Black Rock Valley
 BSMT  M  47 51 04.8  114 47 13.2  1.950  Bassoo Peak, MT
 BUO   %  42 16 42.5  122 14 43.1  1.797  Burton Butte, Oregon
 BVW   +  46 48 39.5  119 52 56.4  0.670  Beverly
 CBS   +  47 48 17.4  120 02 30.0  1.067  Chelan Butte, South
 CDF   %  46 07 01.4  122 02 42.1  0.756  Cedar Flats
 CHMT  M  46 54 51.0  113 15 07.0  -  Chamberlain Mtn, MT
 CMM   %  46 26 07.0  122 30 21.0  0.620  Crazy Man Mt.
 CMW   %  48 25 25.3  122 07 08.4  1.190  Cultus Mtns.
 CPW   %  46 58 25.8  123 08 10.8  0.792  Capitol Peak
 CRF      46 49 30.0  119 23 13.2  0.189  Corfu
 DPW   +  47 52 14.3  118 12 10.2  0.892  Davenport
 DY2   +  47 59 06.6  119 46 16.8  0.890  Dyer Hill 2
 EDM   %  46 11 50.4  122 09 00.0  1.609  East Dome, Mt. St. Helens
 ELK   %  46 18 20.0  122 20 27.0  1.270  Elk Rock
 ELL   +  46 54 34.8  120 33 58.8  0.789  Ellensburg
 EPH   +  47 21 22.8  119 35 45.6  0.661  Ephrata
 ET3   +  46 34 38.4  118 56 15.0  0.286  Eltopia (replaces ET2)
 ETW   +  47 36 15.6  120 19 56.4  1.477  Entiat
 FHE   +  46 57 06.9  119 29 49.0  0.455  Frenchman Hills East
 FL2   %  46 11 47.0  122 21 01.0  1.378  Flat Top 2
 FMW   %  46 56 29.6  121 40 11.3  1.859  Mt. Fremont
 GBB   H  46 36 31.8  119 37 40.2  0.185  PNNL Station
 GBL   +  46 35 54.0  119 27 35.4  0.330  Gable Mountain
 GHW   %  47 02 30.0  122 16 21.0  0.268  Garrison Hill
 GL2   +  45 57 35.0  120 49 22.5  1.000  New Goldendale
 GLK   %  46 33 27.6  121 36 34.3  1.305  Glacier Lake
 GMO   %  44 26 20.8  120 57 22.3  1.689  Grizzly Mountain, Oregon
 GMW   %  47 32 52.5  122 47 10.8  0.506  Gold Mt.
 GPW   %  48 07 05.0  121 08 12.0  2.354  Glacier Peak
 GSM   %  47 12 11.4  121 47 40.2  1.305  Grass Mt.
 GUL   %  45 55 27.0  121 35 44.0  1.189  Guler Mt.
 H2O   H  46 23 45.0  119 25 22.0  -  Water  PNNL Station
 HAM   %  42 04 08.3  121 58 16.0  1.999  Hamaker Mt., Oregon
 HBO   %  43 50 39.5  122 19 11.9  1.615  Huckleberry Mt., Oregon
 HDW   %  47 38 54.6  123 03 15.2  1.006  Hoodsport
 HOG   %  42 14 32.7  121 42 20.5  1.887  Hogback Mtn., Oregon
 HSO   %  43 31 33.0  123 05 24.0  1.020  Harness Mountain, Oregon
 HSR   %  46 10 28.0  122 10 46.0  1.720  South Ridge, Mt. St. Helens
 HTW   %  47 48 14.2  121 46 03.5  0.833  Haystack Lookout
 HUO   %  44 07 10.9  121 50 53.5  2.037  Husband OR (UO)
 JBO   +  45 27 41.7  119 50 13.3  0.645  Jordan Butte, Oregon
 JCW   %  48 11 42.7  121 55 31.1  0.792  Jim Creek
 JUN   %  46 08 50.0  122 09 04.4  1.049  June Lake
 KMO   %  45 38 07.8  123 29 22.2  0.975  Kings Mt., Oregon
 KOS   %  46 27 46.7  122 11 41.3  0.610  Kosmos
 KTR   N  41 54 31.2  123 22 35.4  1.378  CAL-NET
 LAB   %  42 16 03.3  122 03 48.7  1.774  Little Aspen Butte, Oregon
 LAM   N  41 36 35.2  122 37 32.1  1.769  CAL-NET
 LCCM  M  45 50 16.8  111 52 40.8  1.669  Lewis and Clark Caverns, MT
 LCW   %  46 40 14.4  122 42 02.8  0.396  Lucas Creek
 LMW   %  46 40 04.8  122 17 28.8  1.195  Ladd Mt.
 LNO   +  45 52 18.6  118 17 06.6  0.771  Lincton Mt., Oregon
 LO2   %  46 45 00.0  121 48 36.0  0.853  Longmire
 LOC   +  46 43 01.2  119 25 51.0  0.210  Locke Island
 LVP   %  46 03 59.4  122 24 10.2  1.134  Lakeview Peak
 MBW   %  48 47 02.4  121 53 58.8  1.676  Mt. Baker
 MCMT  M  44 49 39.6  112 50 55.8  2.323  McKenzie Canyon, MT
 MCW   %  48 40 46.8  122 49 56.4  0.693  Mt. Constitution
 MDW   +  46 36 47.4  119 45 39.6  0.330  Midway
 MEW   %  47 12 07.0  122 38 45.0  0.097  McNeil Island
 MJ2   +  46 33 27.0  119 21 32.4  0.146  May Junction 2
 MOX   +  46 34 38.4  120 17 53.4  0.501  Moxie City
 MPO   %  44 30 17.4  123 33 00.6  1.249  Mary's Peak, Oregon
 MTM   %  46 01 31.8  122 12 42.0  1.121  Mt. Mitchell
 NAC   +  46 43 59.4  120 49 25.2  0.728  Naches
 NCO   %  43 42 14.4  121 08 18.0  1.908  Newberry Crater, Oregon
 NEL   +  48 04 12.6  120 20 24.6  1.500  Nelson Butte
 NLO   %  46 05 21.9  123 27 01.8  0.826  Nicolai Mt., Oregon
 OBC   %  48 02 07.1  124 04 39.0  0.938  Olympics - Bonidu Creek
 OBH   %  47 19 34.5  123 51 57.0  0.383  Olympics - Burnt Hill
 OCP   %  48 17 53.5  124 37 30.0  0.487  Olympics - Cheeka Peak
 OD2   +  47 23 15.6  118 42 34.8  0.553  Odessa site 2
 OFR   %  47 56 00.0  124 23 41.0  0.152  Olympics - Forest Resource Cen
 OHW   %  48 19 24.0  122 31 54.6  0.054  Oak Harbor
 ON2   %  46 52 50.8  123 46 51.8  0.257  Olympics - North River
 OOW   %  47 44 03.6  124 11 10.2  0.561  Octopus West
 OSD   %  47 48 59.2  123 42 13.7  2.008  Olympics - Snow Dome
 OSR   %  47 30 20.3  123 57 42.0  0.815  Olympics Salmon Ridge
 OT3   +  46 40 08.4  119 13 58.8  0.322  New Othello (replaces OT2 8/26
 OTR   %  48 05 00.0  124 20 39.0  0.712  Olympics - Tyee Ridge
 PAT   +  45 52 55.2  119 45 08.4  0.262  Paterson
 PCMD  %  46 53 20.9  122 18 00.9  0.239  PC Mountain Detachment ANSS-SM
 PGO   %  45 27 42.6  122 27 11.5  0.253  Gresham, Oregon
 PGW   %  47 49 18.8  122 35 57.7  0.122  Port Gamble
 PRO   +  46 12 45.6  119 41 08.4  0.553  Prosser
 RCM   %  46 50 08.9  121 43 54.4  3.085  Mt. Rainier, Camp Muir
 RCS   %  46 52 15.6  121 43 52.0  2.877  Mt. Rainier, Camp Schurman
 RED   H  46 17 51.0  119 26 15.6  0.330  Red Mountain PNNL Station
 RER   %  46 49 09.2  121 50 27.3  1.756  Mt. Rainier, Emerald Ridge
 RMW   %  47 27 35.0  121 48 19.2  1.024  Rattlesnake Mt. (West)
 RNO   %  43 54 58.9  123 43 25.5  0.850  Roman Nose, Oregon
 RPW   %  48 26 54.0  121 30 49.0  0.850  Rockport
 RRHS  %  46 47 58.6  123 02 25.4  0.047  Rochester HS ANSS-SMO
 RSW   +  46 23 40.2  119 35 28.8  1.045  Rattlesnake Mt. (East)
 RVC   %  46 56 34.5  121 58 17.3  1.000  Mt. Rainier - Voight Creek
 RVN   %  47 01 38.6  121 20 11.9  1.885  Raven Roost (former NEHRP temp
 RVW   %  46 08 53.2  122 44 32.1  0.460  Rose Valley
 SAW   +  47 42 06.0  119 24 01.8  0.701  St. Andrews
 SBES  %  48 46 05.9  122 24 54.2  0.119  Silver Beach ES SMO
 SEA   %  47 39 15.8  122 18 29.3  0.030  UW, Seattle (Wood Anderson BB
 SEP   #  46 12 00.7  122 11 28.1  2.116  September lobe, Mt. St. Helens
 SFER  %  47 37 10.4  117 21 55.7  -  Spokane Schools, Ferris High S
 SHW   %  46 11 37.1  122 14 06.5  1.425  Mt. St. Helens
 SLF   %  47 45 32.0  120 31 40.0  1.750  Sugar Loaf
 SMW   %  47 19 10.7  123 20 35.4  0.877  South Mtn.
 SNI   H  46 27 80.0  119 39 50.0  -  PNNL station
 SOS   %  46 14 38.5  122 08 12.0  1.270  Source of Smith Creek
 SSO   %  44 51 21.6  122 27 37.8  1.242  Sweet Springs, Oregon
 STD   %  46 14 16.0  122 13 21.9  1.268  Studebaker Ridge
 STW   %  48 09 03.1  123 40 11.1  0.308  Striped Peak
 SVOH  %  48 17 21.8  122 37 54.8  0.010  Skagit Valley CC ANSS-SMO
 TBM   +  47 10 12.0  120 35 52.8  1.006  Table Mt.
 TCO   %  44 06 27.6  121 36 02.1  1.975  Three Creek Meadows, Oregon.
 TDH   %  45 17 23.4  121 47 25.2  1.541  Tom,Dick,Harry Mt., Oregon
 TDL   %  46 21 03.0  122 12 57.0  1.400  Tradedollar Lake
 TRW   +  46 17 32.0  120 32 31.0  0.723  Toppenish Ridge
 TWW   +  47 08 17.4  120 52 06.0  1.027  Teanaway
 UWFH  %  48 32 46.0  123 00 43.0  0.010  UW Friday Harbor ANSS-SMO
 VBE   %  45 03 37.2  121 35 12.6  1.544  Beaver Butte, Oregon
 VCR   %  44 58 58.2  120 59 17.4  1.015  Criterion Ridge, Oregon
 VDB   C  49 01 34.0  122 06 10.1  0.404  Canada
 VFP   %  45 19 05.0  121 27 54.3  1.716  Flag Point, Oregon
 VG2   %  45 09 20.0  122 16 15.0  0.823  Goat Mt., Oregon
 VGB   +  45 30 56.4  120 46 39.0  0.729  Gordon Butte, Oregon
 VGZ   C  48 24 50.0  123 19 27.8  0.067  Canada
 VIP   %  44 30 29.4  120 37 07.8  1.731  Ingram Pt., Oregon
 VLL   %  45 27 48.0  121 40 45.0  1.195  Laurance Lk., Oregon
 VLM   %  45 32 18.6  122 02 21.0  1.150  Little Larch, Oregon
 VSP   %  42 20 30.0  121 57 00.0  1.539  Spence Mtn, Oregon
 VT2   +  46 58 02.4  119 59 57.0  1.270  Vantage2
 VTH   %  45 10 52.2  120 33 40.8  0.773  The Trough, Oregon
 WA2   +  46 45 19.2  119 33 56.4  0.244  Wahluke Slope
 WAT   +  47 41 55.2  119 57 14.4  0.821  Waterville
 WIB   %  46 20 34.8  123 52 30.6  0.503  Willapa Bay
 WIW   +  46 25 45.6  119 17 15.6  0.128  Wooded Island
 WPO   %  45 34 24.0  122 47 22.4  0.334  West Portland, Oregon
 WPW   %  46 41 55.7  121 32 10.1  1.280  White Pass
 WRD   +  46 58 12.0  119 08 41.4  0.375  Warden
 WRW   %  47 51 26.0  120 52 52.0  1.189  Wenatchee Ridge
 YA2   +  46 31 36.0  120 31 48.0  0.652  Yakima
 YEL   #  46 12 35.0  122 11 16.0  1.750  Yellow Rock, Mt. St. Helens
 YPT   +  46 02 55.8  118 57 44.0  0.325  Yellepit

Table 1B lists broad-band stations used in locating seismic events in Washington and Oregon.

TABLE 1B
Broad-band three-component stations operating at the end of the fourth quarter 2001. Symbols are as in Table 1A.
STA  F  LAT  LONG  EL  NAME
 BRKS  %  47 45 19.1  122 17 17.9  0.020  Brookside  ANSS-SMO
 COR   U  44 35 08.5  123 18 11.5  0.121  Corvallis, Oregon (OSU BB )
 DBO   %  43 07 09.0  123 14 34.0  0.984  Dodson Butte, Oregon (UO CREST
 ELW   %  47 29 39.4  121 52 17.2  0.267  EchoLakeBPA BB-SMO-IDS20
 ERW   %  48 27 14.4  122 37 30.2  0.389  Mt. Erie SMO-IDS24 BB
 EUO   %  44 01 45.7  123 04 08.2  0.160  Eugene,OR U0 CREST BB SMO
 GNW   %  47 33 51.8  122 49 31.0  0.165  Green Mt CREST BB SMO
 HAWA  U  46 23 32.3  119 31 57.2  0.367  Hanford Nike USNSN BB
 HLID  U  43 33 45.0  114 24 49.3  1.772  Hailey, ID USNSN BB
 KSXB  N  41 49 51.0  123 52 33.0  -  Camp Six, OR CREST BB
 KEB   N  42 52 20.0  124 20 03.0  0.818  Edson Butte, OR CREST BB
 KRMB  N  41 31 23.0  123 54 29.0  1.265  Red Mtn, OR CREST BB
 LON   %  46 45 00.0  121 48 36.0  0.853  Longmire CREST BB LONLZ SMO
 LTY   %  47 15 21.2  120 39 53.3  0.970  Liberty (BB)
 NEW   U  48 15 50.0  117 07 13.0  0.760  Newport Observatory USNSN BB
 OCWA  U  47 44 56.0  124 10 41.2  0.671  Octopus Mtn. USNSN BB
 OFR   %  47 56 00.0  124 23 41.0  0.152  Olympics - Forest Resource Cen
 OPC   %  48 06 01.0  123 24 41.8  0.090  Olympic Penn College CREST BB
 PIN   %  43 48 40.0  120 52 19.0  1.865  Pine Mt., Oregon  (U0 CREST, B
 PNT   C  49 18 57.6  119 36 57.6  0.550  Canada,  BB
 RAI      46 02 25.1  122 53 06.4  1.520  Trojan Plant, Oregon (OSU BB)
 RWW   %  46 57 53.7  123 32 31.7  0.015  Ranney Well CREST BB SMO
 SEA   %  47 39 15.8  122 18 29.3  0.030  UW, Seattle (Wood Anderson BB
 SNB   C  48 46 33.6  123 10 16.3  0.408  Canada BB
 SP2   %  47 33 23.3  122 14 52.8  0.030  Seward Park, Seattle SMO-IDS24
 SQM   %  48 04 39.0  123 02 44.0  0.030  Sequim, WA (CREST BB SMO)
 TAKO  %  43 44 36.0  124 04 56.0  0.100  Tahkenitch, OR CREST BB SMO
 TOLO  %  44 37 19.0  123 55 21.0  0.100  Toledo BPA, OR CREST BB SMO
 TTW   %  47 41 40.7  121 41 20.0  0.542  Tolt Res, WA CREST BB SMO
 WVOR  U  42 26 02.0  118 38 13.0  1.344  Wildhorse Valley, Oregon (USNS

Table 1C lists strong-motion, three-component stations operating in Washington and Oregon that provide data in real or near-real time to the PNSN. Several of these stations also have broad-band instruments, as noted. The "SENSOR" field designates what type of seismic sensor is used;
  • A = Terra-Tech SSA-320 SLN triaxial accelerometer/Terra-Tech IDS24
  • A20 = Terra-Tech SSA-320 triaxial accelerometer/Terra-Tech IDS20 recording system,
  • FBA23 = Kinemetrics FBA23 accelerometers and Reftek recording system,
  • EPI = Kinemetrics Episensor accelerometers and Reftek recording system.
  • BB = Guralp CMG-40T 3-D broadband velocity sensor.
  • BB3 = Guralp CMG3T 3-D broadband velocity sensor.
  • BBZ = Broad Band sensor, PMD 2024, vertical component only.
  • K2 = Kinemetrics Episensor accelerometers and K2 Recording System
  • The "TELEMETRY" field indicates the type of telemetry used to recover the data.
  • D = dial-up,
  • E = continuously telemetered via Internet from a remote EARTHWORM system
  • I = continuously telemetered via Internet,
  • L = continuously telemetered via dedicated lease-line telephone lines,
  • L-PPP = continuously telemetered via dedicated lease-line telephone lines using PPP protocol
  • M = continuously telemetered via BPA microwave
  • R = continuously telemetered via spread-spectrum radio
    TABLE 1C
    
    Strong-motion three-component stations operating at the end of the fourth quarter 2001. Symbols are as in Table 1A. STA F LAT LONG EL NAME SENSORS TELEMETRY ALCT % 47 38 48.8 122 2 15.7 0.055 Alcott Elementary K2 I ALST % 46 6 32.3 123 1 58.5 0.198 Alston A20 E,M ALVY % 43 59 53.2 123 0 57.0 0.155 Alvey K2 E,M ATES % 48 14 10.9 122 3 33.0 0.010 Trafton Elementary K2 I BABE % 47 36 21.0 122 32 7.0 0.010 Blakely Elementary K2 I BEVT % 47 55 12.0 122 16 12.0 0.170 Boeing Plant Everett K2 I BRKS % 47 45 19.1 122 17 17.9 0.020 Brookside Elementary K2,BBZ I CSEN % 47 48 4.5 122 13 6.5 0.055 Crystal Springs Elementary K2 I CSO # 45 31 1.0 122 41 22.5 0.036 Canyon FBA23 D DBO % 43 7 9.0 123 14 34.0 0.984 Dodson Butte (CREST) EPI,BB3 E,L-PPP EARN % 47 44 27.2 122 2 37.7 0.159 East Ridge Elementary K2 I EGRN % 47 4 24.0 122 58 41.0 0.010 Evergreen State College K2 None ELW % 47 29 39.4 121 52 17.2 0.267 Echo Lake A,BB D,M,L ERW % 48 27 14.4 122 37 30.2 0.389 Mount Erie A,BB D,L,M EUO % 44 1 45.7 123 4 8.2 0.160 Eugene Golf Course (CREST) EPI,BB E,L-PPP EVCC % 48 0 27.0 122 12 15.3 0.000 Everett Community College K2 None EVGW % 47 51 15.8 122 9 12.2 0.010 Gateway Middle School K2 I FINN % 47 43 10.2 122 13 55.9 0.121 Finn Hill Junior High K2 I GNW % 47 33 51.8 122 49 31.0 0.165 Green Mountain (CREST) EPI,BB3 L-PPP HAO # 45 30 33.1 122 39 24.0 0.018 Harrison FBA23 D HICC % 47 23 24.4 122 17 52.4 0.115 Highline Community College K2 I HOLY % 47 33 55.4 122 23 1.0 0.106 Holy Rosary School K2 I KDK % 47 35 42.7 122 19 56.0 0.004 King Dome K2 None KEEL % 45 33 0.8 122 53 42.4 0.067 Keeler A20 D,E,M KICC % 47 34 37.9 122 37 52.4 0.010 Kitsap County Central Communications K2 None KIMB % 47 34 29.3 122 18 10.1 0.069 Kimball Elementary K2 I KIMR % 47 30 11.0 122 46 2.0 0.123 Moderate Risk Waste Collection Facility K2 I KINR % 47 45 6.0 122 38 35.0 0.010 North Road Shed K2 I KITP % 47 40 30.0 122 37 47.0 0.076 Wastewater Treatment Plant K2 I KNJH % 47 23 5.0 122 13 42.0 0.010 Kent Junior High K2 I LANE % 44 3 6.5 123 13 54.8 0.120 Lane K2 E,M LAWT % 47 39 23.4 122 23 21.9 0.050 Lawton Elementary A20 I LEOT % 47 46 4.4 122 6 56.2 0.115 Leota Junior High K2 I LON % 46 45 0.0 121 48 36.0 0.853 Longmire Springs (CREST) EPI,BB3 L-PPP LTY % 47 15 21.2 120 39 53.4 0.970 Liberty Heights Mine (CREST) BB3 I MARY % 47 39 45.7 122 7 11.6 0.011 Marymoor Park K2 I MBKE % 48 55 2.0 122 8 29.0 1.010 Kendall Elementary K2 I MBPA % 47 53 54.7 121 53 20.2 0.186 Monroe A20 D,M,L MPL % 47 28 7.0 122 11 4.5 0.122 Maple Valley A D,M,L MURR % 47 7 12.0 122 33 36.0 0.100 Camp Murray K2 None NOWS % 47 41 12.0 122 15 21.2 0.002 NOAA Sand Point A20 I OHC % 47 20 2.0 123 9 29.0 0.010 Hood Canal Junior High K2 I OPC % 48 6 1.0 123 24 41.8 0.090 Peninsula College (CREST) EPI,BB I PAYL % 47 11 34.0 122 18 46.0 0.010 Aylen Junior High K2 I PCEP % 47 6 41.8 122 17 24.0 0.160 Puyallup East Sheriff Precinct K2 I PCFR % 46 59 23.3 122 26 27.4 0.137 Roy Training Center K2 I PCMD % 46 53 20.9 122 18 0.9 0.239 Mountain Detachment K2 I PIN % 43 48 40.0 120 52 19.0 1.865 Pine Mtn. (CREST) EPI,BB3 E,L-PPP PNLK % 47 34 54.5 122 2 1.0 0.128 Pine Lake Middle School K2 I QAW % 47 37 54.3 122 21 15.5 0.140 Queen Anne A20 L RAW % 47 20 14.0 121 55 53.2 0.208 Raver A20 M,L RBEN % 47 26 6.7 122 11 10.0 0.152 Benson Hill Elementary K2 I RBO # 45 32 27.0 122 33 51.5 0.158 Rocky Butte FBA23 D RHAZ % 47 32 24.7 122 11 1.3 0.108 Hazelwood Elementary A20 I ROSS % 45 39 43.0 122 39 25.0 0.061 Ross A20 E RRHS % 46 47 58.6 123 2 25.4 0.047 Rochester High School K2 I RWW % 46 57 53.7 123 32 31.7 0.015 Ranney Well (CREST) EPI,BB3 L-PPP SBES % 48 46 5.9 122 24 54.2 0.119 Silver Beach Elementary School K2 I SEA % 47 39 15.8 122 18 29.3 0.030 University of Washington A20,PMD2023 L SFER % 47 37 10.4 117 21 55.7 0.000 Ferris High School K2 I SGAR % 47 40 37.8 117 24 50.3 0.579 Garfield Elementary K2 I SMNR % 47 12 16.6 122 12 53.4 0.010 Sumner High School K2 I SP2 % 47 33 23.3 122 14 52.8 0.030 Seward Park A,BB L SQM % 48 4 39.0 123 2 44.0 0.030 Sequim Battelle Properties (CREST) EPI,BB I,R SVOH % 48 17 21.8 122 37 54.8 0.010 Skagit Valley College Oak Harbor K2 I SWES % 47 42 51.0 117 27 53.2 0.623 Westview Elementary K2 I SWID % 48 0 31.0 122 24 42.0 0.010 South Whidbey Primary School K2 I TAKO % 43 44 36.0 124 4 56.0 0.100 Tahkenitch (CREST) EPI,BB M,E TBPA % 47 15 29.0 122 22 1.0 0.002 Tacoma A20 M,L,D TKCO % 47 32 12.7 122 18 1.5 0.005 King County Airport A20 I TOLO % 44 37 19.0 123 55 21.0 0.100 Toledo (CREST) EPI,BB ME TTW % 47 41 40.7 121 41 20.0 0.542 Tolt Reservoir (CREST) EPI,BB3 I UPS % 47 15 50.2 122 29 1.1 0.113 University of Puget Sound K2 I UWFH % 48 32 46.0 123 0 43.0 0.010 Friday Harbor Laboratories K2 I VVHS % 47 25 25.1 122 27 13.1 0.095 Vashon High School K2 I WISC % 47 36 32.0 122 10 27.8 0.056 Wilburton Instructional Services Center K2 I

    Data Processing

    The PNSN seismic recording system uses real-time telemetry, and operates in an `event triggered' mode. Analog and strong-motion digital data are recorded at 100 samples per sec., while broad-band digital data are digitized at 40 or 50 samples per sec. Arrival times, first motion polarities, signal durations, signal amplitudes, locations and focal mechanisms (when possible) are determined in post-processing. Digital data are processed for all locatable teleseisms, regional events, and local events. Each trace data file has an associated `pickfile' which includes arrival times, polarities, coda lengths, and other data.

    EARTHWORM is our main PNSN data-acquisition system. The old SUNWORM system operates as a digitizer for the analog stations. Analog stations, and most digital stations, are continuously telemetered in real time. Only one broadband stations (LTY) and three USGS strong-motion stations in Portland record only on-site. Data are retrieved via dial-up modem, if needed. All of the real-time data are continuously recorded into temporary storage areas called "wave tanks" which can accommodate about 24 hours of continuous data for the entire network. Triggering algorithms create individual event files.

    Continuous data are archived for a small subset of stations, usually about 20, mostly on volcanoes. We continue to use the UW2 pickfile and data formats, and analysis tools which have been in place for the past several years.

    Unedited network-trigger trace data are stored on ongoing "network-archive" backup tapes. Edited "Master Event" trace data files are kept for all seismic events. These "Master Event" files are also translated to IRIS-SEED format and submitted to the IRIS Data Management Center for archive and distribution.

    Through EARTHWORM, we exchange real-time data with the University of Oregon, The Battelle Pacific Northwest National Labs, the Pacific Geoscience Centre, the Montana Bureau of Mines, and CALNET. In addition, we send real-time data to the Alaska Tsunami Warning Center, the Pacific Tsunami Warning Center, the Cascade Volcano Observatory, and the National Earthquake Information Center,

    The entire PNSN catalog has been contributed to the CNSS composite catalog located at the Northern California Earthquake Data Center. The PNSN section of the CNSS catalog is updated daily.

    Starting in the fall of 2001, we started shipping a large portion of our waveform data to the IRIS DMC in near real time. This was done by running the ew2seed program at IRIS whcih connects to our EARTHWORM waveservers and extracts 1/2 hour of data at a time. Sevral months of testing proved sucessful. At the end of the year we started sending all PNSN traces from all wave servers so that IRIS has a complete copy of all our continuous data in the BUD (Buffer of Uniform Data) system.

    Publications

    Publications wholly or partly supported under this operating agreement are listed in Appendix 2.

    SEISMICITY, EMERGENCY NOTIFICATION, AND OUTREACH

    Seismicity

    Figure 2 shows earthquakes of magnitude 2.0 or larger located in Washington and Oregon during this reporting period. Table 2 lists earthquakes recorded by the PNSN during 2001 which were reported felt. Table 3 gives information on seismic activity recorded at the PNSN annually since 1980. During this reporting period there were 23 earthquakes reported felt west of the Cascades in Washington, ranging in magnitude from 1.7 to 6.8. Only one Oregon earthquake was reported felt this year; a magnitude 1.9 event.

    By far the most interesting event during the reporting period was the moment-magnitude 6.8 Nisqually earthquake of Feb. 28, 2001. It occurred at a depth of about 52 km, about 18 km northeast of Olympia, WA. Extensive information is available on the Nisqually Earthquake Clearinghouse:
    http://maximus.ce.washington.edu/~nisqually/index.html
    A great deal has been and will be written about the Nisqually earthquake, which caused significant damages. Only four small aftershocks were recorded in the two weeks following the mainshock, but a possible late aftershock of magnitude 4.3 occurred nearby about six months later. Appendix 3 is a reprint of the PNSN's "Preliminary Report on the Mw=6.8 Nisqually, Washington Earthquake of 28, February 2001", from Seismological Research Letters, V. 72, N. 3, pp. 352-361.

    The 2001 Nisqually earthquake was the largest of a unusual series of Benioff zone earthquakes that began in July 1999 with a M 5.8 earthquake at about 41 km depth beneath Satsop WA. The Nisqually earthquake, in Feb. 2001, was east of the Satsop earthquake and, at 52 km, deeper. A M 5.0 earthquake on June 10, 2001 was near the location and depth of the 1999 Satsop earthquake, and a M 4.3 earthquake on July 22 (UTC) was close to the location and depth of the Nisqually event.

    East of the Cascades in Washington, more than 70 earthquakes were felt during 2001. Many of these were tiny events in the Spokane urban area, where a vigorous sequence of earthquakes began in May. Activity continued in bursts, with the largest earthquake M 4.0 on November 11. No comparable sequence is known in the history of Spokane. For additional details see the quarterly reports, or the PNSN web page "The 2001 Spokane Earthquake Sequence":
    http://www.ess.washington.edu/SEIS/EQ_Special/WEBDIR_01062514151n/overview.html
    Magnitudes of the Spokane felt earthquakes ranged from -0.9 to 4.0. Network coverage was initially sparse, and in addition to the 98 locatable earthquakes, there were many additional felt events early in the sequence too small to locate.

    TABLE 2
    Felt Earthquakes during 2001
    DATE-(UTC)-TIME  LAT(N)  LON(W)  DEPTH  MAG  COMMENTS
    yy/mm/dd hh:mm:ss    deg.    deg.     km      
    01/02/14 03:54:54   48.75N  123.12W   20.9  2.3       26.0 km NNW of Friday Harbor, WA
    01/02/14 22:03:58   47.51N  121.89W    6.6  3.1        5.4 km   S of Fall City, WA
    01/02/24 07:40:50   47.53N  122.06W   22.6  2.2       13.2 km  SE of Bellevue, WA
    01/02/28 07:16:13   47.75N  120.03W    0.6  3.2       10.2 km   S of Chelan, WA
    01/02/28 18:54:32   47.14N  122.72W   51.9  6.8       17.0 km  NE of Olympia, WA
    01/03/01 09:10:20   47.19N  122.71W   54.3  3.4       21.6 km  NE of Olympia, WA
    01/03/01 14:23:34   47.18N  122.72W   51.4  2.7       19.4 km  NE of Olympia, WA
    01/03/10 06:26:05   47.48N  122.79W   19.3  1.7       15.9 km  SW of Bremerton, WA
    01/03/11 17:08:54   47.60N  121.91W   21.6  2.9        4.4 km NNW of Fall City, WA
    01/03/16 02:41:11   47.56N  122.07W   18.1  2.2       10.2 km ESE of Bellevue, WA
    01/03/21 10:31:05   46.21N  121.02W    0.9  2.9       35.4 km   E of Mt Adams, WA
    01/04/07 16:02:35   48.72N  124.76W   41.8  3.9       90.6 km NNW of Forks, WA
    01/06/10 13:19:11   47.16N  123.50W   40.7  5.0       18.3 km   N of Satsop, WA
    01/06/25 14:15:22   47.68N  117.39W   10.5  3.9        1.5 km  NE of Spokane, WA (Mission & N Division)
    01/06/25 15:01:27   47.70N  117.41W   11.1  3.4        3.3 km   N of Spokane, WA (Mission & N Division)
    01/06/25 16:49:16   47.73N  117.47W    0.0  2.3        8.7 km NNW of Spokane, WA (Mission & N Division)
    01/06/25 22:58:13   47.72N  117.46W    0.0  2.3        6.8 km NNW of Spokane, WA (Mission & N Division)
    01/06/26 01:21:21   47.75N  117.48W    0.0  2.1       11.1 km NNW of Spokane, WA (Mission & N Division)
    01/06/26 05:52:26   47.75N  117.48W    8.0  2.4       10.6 km NNW of Spokane, WA (Mission & N Division)
    01/06/27 09:07:45   47.72N  117.45W    0.4  2.4        6.5 km NNW of Spokane, WA (Mission & N Division)
    01/06/27 14:45:37   47.70N  117.41W    7.3  2.9        4.2 km   N of Spokane, WA (Mission & N Division)
    01/06/28 07:51:42   47.67N  117.39W    0.4  2.3        1.4 km  NE of Spokane, WA (Mission & N Division)
    01/06/28 11:47:48   47.67N  117.41W    0.5  0.7        0.4 km WNW of Spokane, WA (Mission & N Division)
    01/06/29 01:13:27   47.68N  117.42W    0.5  2.4        1.7 km NNW of Spokane, WA (Mission & N Division)
    01/06/30 01:23:31   46.85N  121.97W    7.7  3.3       16.2 km   W of Mt Rainier, WA
    01/07/01 05:44:13   47.67N  117.41W    0.5  2.9        0.5 km   N of Spokane, WA (Mission & N Division)
    01/07/01 05:45:43   47.68N  117.40W    0.8  2.9        1.8 km NNE of Spokane, WA (Mission & N Division)
    01/07/01 06:07:13   47.68N  117.41W    0.4  2.3        1.0 km NNW of Spokane, WA (Mission & N Division)
    01/07/02 17:48:29   47.67N  117.42W    0.4  0.8        1.1 km  NW of Spokane, WA (Mission & N Division)
    01/07/03 21:20:27   47.67N  117.41W    0.5  2.2        0.7 km NNW of Spokane, WA (Mission & N Division)
    01/07/08 11:16:32   47.68N  117.41W    0.5  1.5        1.5 km NNW of Spokane, WA (Mission & N Division)
    01/07/16 11:37:35   45.11N  122.51W   13.1  1.9       21.4 km  SE of Canby, OR
    01/07/22 15:13:52   47.08N  122.68W   52.4  4.3       16.3 km ENE of Olympia, WA
    01/07/24 13:31:06   47.49N  122.02W   16.4  2.2        9.3 km   N of Maple Valley, WA
    01/07/29 06:26:53   47.68N  117.41W    0.4  2.3        1.1 km NNW of Spokane, WA (Mission & N Division)
    01/07/29 06:37:58   47.68N  117.41W    0.2  1.3        1.6 km NNW of Spokane, WA (Mission & N Division)
    01/07/29 07:04:24   47.66N  117.39W    0.3  1.2        1.5 km  SE of Spokane, WA (Mission & N Division)
    01/07/30 20:35:08   47.67N  117.42W    0.3  1.8        1.4 km  NW of Spokane, WA (Mission & N Division)
    01/07/31 01:38:10   47.68N  117.40W    0.5  3.2        1.8 km NNE of Spokane, WA (Mission & N Division)
    01/07/31 05:07:31   47.68N  117.41W    0.4  2.2        1.3 km NNW of Spokane, WA (Mission & N Division)
    01/07/31 05:24:33   47.69N  117.42W    0.5  1.5        2.4 km NNW of Spokane, WA (Mission & N Division)
    01/07/31 06:48:11   47.71N  117.47W    0.5  1.8        6.9 km  NW of Spokane, WA (Mission & N Division)
    01/07/31 08:51:55   47.72N  117.45W    2.1  1.6        7.1 km NNW of Spokane, WA (Mission & N Division)
    01/07/31 16:27:42   47.68N  117.42W    0.5  1.8        1.5 km  NW of Spokane, WA (Mission & N Division)
    01/08/01 14:29:48   47.67N  117.42W    0.5  2.2        0.9 km WNW of Spokane, WA (Mission & N Division)
    01/08/09 13:31:23   47.68N  117.42W    0.8  1.5        1.7 km  NW of Spokane, WA (Mission & N Division)
    01/08/14 13:28:27   44.28N  125.46W   10.0  1.5      119.1 km WSW of Newport, OR
    01/08/19 06:17:32   48.25N  121.61W    1.7  3.0        1.0 km WSW of Darrington, WA
    01/08/25 17:52:34   48.23N  121.60W    2.7  2.1        2.1 km   S of Darrington, WA
    01/08/30 03:47:31   48.23N  121.62W    4.8  2.7        2.9 km  SW of Darrington, WA
    01/09/28 18:34:53   47.68N  117.38W    1.8  2.8        2.1 km  NE of Spokane, WA (Mission & N Division)
    01/09/28 18:37:53   47.66N  117.37W    0.3  1.9        2.7 km ESE of Spokane, WA (Mission & N Division)
    01/09/28 18:38:37   47.67N  117.40W    0.6  2.6        0.7 km NNE of Spokane, WA (Mission & N Division)
    01/09/28 18:41:40   47.67N  117.39W    0.0  1.6        1.0 km ENE of Spokane, WA (Mission & N Division)
    01/10/05 02:26:41   48.82N  122.11W   12.1  3.0        7.6 km   E of Deming, WA
    01/10/06 10:52:09   48.83N  122.10W   13.2  3.0        8.2 km   E of Deming, WA
    01/10/15 04:57:01   48.15N  123.06W   44.4  2.9       28.6 km   E of Port Angeles, WA
    01/11/10 18:30:59   48.93N  123.04W   15.4  3.4       21.7 km   S of Vancouver,BC
    01/11/11 16:00:29   47.68N  117.40W    4.7  4.0        2.0 km NNE of Spokane, WA (Mission & N Division)
    01/11/11 17:21:33   47.68N  117.40W    0.6  3.1        1.3 km NNE of Spokane, WA (Mission & N Division)
    01/11/12 03:03:02   47.68N  117.40W    0.6  3.3        2.0 km   N of Spokane, WA (Mission & N Division)
    01/11/12 03:07:40   47.68N  117.41W    0.6  1.9        1.7 km   N of Spokane, WA (Mission & N Division)
    01/11/12 03:11:15   47.68N  117.41W    0.6  2.4        1.9 km NNW of Spokane, WA (Mission & N Division)
    01/11/12 11:44:18   47.68N  117.39W    0.6  1.7        2.4 km  NE of Spokane, WA (Mission & N Division)
    01/11/12 13:25:59   47.68N  117.40W    0.5  1.9        2.0 km NNE of Spokane, WA (Mission & N Division)
    01/11/13 05:41:45   47.69N  117.40W    0.6  2.3        2.4 km   N of Spokane, WA (Mission & N Division)
    01/11/13 07:39:05   47.68N  117.42W    0.6  2.1        1.4 km  NW of Spokane, WA (Mission & N Division)
    01/11/13 10:14:01   48.86N  122.46W   22.0  2.5       11.7 km   N of Bellingham, WA
    01/11/13 20:26:26   47.69N  117.40W    0.6  3.0        2.2 km NNE of Spokane, WA (Mission & N Division)
    01/11/14 01:50:51   47.69N  117.38W    0.6  1.2        3.6 km  NE of Spokane, WA (Mission & N Division)
    01/11/14 16:41:20   47.69N  117.32W    0.6  1.6        7.3 km ENE of Spokane, WA (Mission & N Division)
    01/11/15 00:11:46   47.69N  117.39W    0.0  2.1        2.7 km NNE of Spokane, WA (Mission & N Division)
    01/11/16 01:42:29   47.68N  117.39W    0.5  1.8        2.2 km  NE of Spokane, WA (Mission & N Division)
    01/11/17 16:18:49   47.68N  117.42W    0.4  1.4        1.9 km NNW of Spokane, WA (Mission & N Division)
    01/11/18 19:51:12   47.68N  117.42W    0.8  1.6        1.5 km  NW of Spokane, WA (Mission & N Division)
    01/11/19 04:47:06   47.68N  117.41W    2.2  1.2        1.5 km NNW of Spokane, WA (Mission & N Division)
    01/11/19 04:47:52   47.69N  117.41W    1.2  0.5        2.9 km NNW of Spokane, WA (Mission & N Division)
    01/11/20 06:03:56   47.67N  117.44W    2.6  1.0        2.3 km WNW of Spokane, WA (Mission & N Division)
    01/11/20 12:14:42   47.67N  117.44W    0.0  1.4        2.5 km   W of Spokane, WA (Mission & N Division)
    01/11/22 04:43:01   47.68N  117.42W    2.5  1.4        1.2 km  NW of Spokane, WA (Mission & N Division)
    01/11/24 00:32:10   47.67N  117.43W    2.1  -0.5       1.6 km WNW of Spokane, WA (Mission & N Division)
    01/11/26 04:13:15   47.68N  117.42W    2.2   0.9       1.6 km NNW of Spokane, WA (Mission & N Division)
    01/11/26 09:41:37   47.69N  117.40W    0.0  -0.8       3.0 km NNE of Spokane, WA (Mission & N Division)
    01/11/26 09:41:53   47.68N  117.43W    2.1   0.0       1.8 km  NW of Spokane, WA (Mission & N Division)
    01/11/26 09:59:53   47.68N  117.38W    4.7  -1.6       2.3 km  NE of Spokane, WA (Mission & N Division)
    01/11/26 10:12:11   47.68N  117.40W    2.3  -1.6       1.6 km   N of Spokane, WA (Mission & N Division)
    01/11/26 11:56:07   47.68N  117.41W    2.2   0.7       1.8 km   N of Spokane, WA (Mission & N Division)
    01/11/27 08:26:58   47.65N  117.44W    0.5  -0.9       3.4 km  SW of Spokane, WA (Mission & N Division)
    01/12/06 23:24:08   46.89N  122.36W   20.4   2.4       8.1 km WNW of Eatonville, WA
    01/12/19 06:39:26   47.69N  117.38W    0.0  -0.8       3.1 km NNE of Spokane, WA (Mission & N Division)
    01/12/19 21:32:17   47.67N  117.44W    2.0  -0.8       2.2 km WNW of Spokane, WA (Mission & N Division)
    01/12/20 03:03:20   47.67N  117.44W    2.0  -0.5       2.3 km   W of Spokane, WA (Mission & N Division)
    01/12/20 08:30:43   47.67N  117.43W    1.8  -0.1       2.1 km   W of Spokane, WA (Mission & N Division)
    01/12/25 03:58:53   47.68N  117.42W    0.2  -0.7       1.7 km  NW of Spokane, WA (Mission & N Division)
    01/12/27 22:11:20   47.66N  117.43W    0.0  -0.5       2.0 km   W of Spokane, WA (Mission & N Division)
    01/12/29 11:57:27   47.67N  117.43W    0.0  -0.8       2.0 km   W of Spokane, WA (Mission & N Division)
    

    TABLE 3
    Annual counts of events recorded by the PNSN, 1980-2001
    Year  Total #  Out of Net  Inside Net  
          Unlocated  Located    
            Total  EQs(#felt)  Blasts
    80  4576  253  1075  3246  2874(18)  372
    81  5155  291  1474  3385  2672(29)  713
    82  4452  329  1824  2297  1948(20)  349
    83  4489  405  2338  1745  1356(15)  389
    84  3144  267  1095  1780  1409(16)  371
    85  3560  266  1168  2122  1890(16)  232
    86  2554  318  452  1776  1594(21)  182
    87  1981  537  127  1304  966(22)  338
    88  2249  507  114  1624  1263(19)  361
    89  2781  501  137  2136  1835(38)  301
    90  3433  717  204  2505  2096(26)  409
    91  3083  675  315  2085  1687(26)  398
    92  3522  891  235  2381  1993(22)  388
    93  5594  731  626  4224  3877(35)  347
    94  6243  900  1518  3816  3424(28)  392
    95  5354  959  1462  2915  2539(16)  376
    96  4741  911  1192  2628  2214(39)  414
    97  3881  728  904  2239  1992(35)  247
    98  7463  831  2174  4430  4176(11)  254
    99  4505  803  1483  2187  1965(30)  222
    00  5625  1121  1686  2818  2482(18)  341
    01  5945  1090  2106  2730  2258(95)  472
    

    Emergency Notification

    The RACE system, discussed earlier, is a pager-based alarm system that updates earthquake locations on a map displayed on a PC screen. When a "significant" event (magnitude 2.9 or larger) is located by the PNSN automatic systems, a preliminary location and magnitude is sent within minutes to seismologists and the RACE system via pager. The same information is forwarded via fax and e-mail to others with critical need. A set of web-pages on earthquakes magnitude 3.3 and larger are automatically generated and linked to the PNSN web-site. These preliminary messages are rapidly followed by final processing and update of the RACE systems, faxes, e-mail, and web-site, within 20 minutes to an hour.

    Public Information and Outreach

    Summary lists for all earthquakes located by the PNSN since 1969 are available via anonymous ftp on ftp.geophys.washington.edu in the pub/seis_net subdirectory. This information is also available via the PNSN World-Wide-Web(WWW) site.


    http://www.geophys.washington.edu/SEIS/PNSN/
    Our web-server contains text about earthquakes in the Pacific Northwest, maps of stations, catalogs and maps of recent earthquake activity, and maps and text about recent interesting sequences. It also contains links into other sources of earthquake information around the country and world.

    The PNSN has an educational outreach program to better inform the public, policy makers, and emergency managers about seismicity and natural hazards. We provide information sheets, lab tours, workshops, and media interviews, and have an audio library with several tapes. We organize and participate in special events in addition to our normal background of informational work; including several thousand calls per quarter to our audio library; tours of the PNSN lab by hundreds of students, teachers, and parents; and outreach talks to numerous groups of all types.

    This year was a another very busy one for the PNSN!

  • The M 6.8 Nisqually earthquake on February 28th was followed by intense national media attention, with a high demand for interviews and information. FEMA funding was obtained for The Nisqually Earthquake Clearinghouse (hosted by the PNSN) to collect and organize data related to the earthquake. The Clearinghouse operated through the end of September.
  • High demand for public information continued as additional western Washington Benioff zone earthquakes (M 5.0 and M 4.3) occurred in June and July, and a swarm of small earthquakes, in sporadic bursts from June through December, were felt by many in downtown Spokane.
  • PNSN staff met with numerous state and county officials, representatives of utility and private companies, and engineering and emergency management groups regarding rapid earthquake notification and long-term network and strong-motion development plans. The PNSN installed a RACE System at the WSDOT Seattle Operations Center.
  • Many presentations were given; to professional groups such as the Washington State Emergency Managers Association (WSEMA), the Western States Seismic Policy Council (WSSPC), the Contingency Planners And Recovery Managers (CPARM), the Western Washington Emergency Network conference, the Oregon Seismic Safety Policy Advisory Committee, and the the Washington Seismic Safety Committee; and to general audiences at functions including Disaster Saturday, the Burke Museum, the Olympic Peninsula Intertribal Cultural Advisory Committee, the Association of Geo-science Educators, the Seattle Middle Schools Science Fair.
  • The PNSN hosted meetings of the ANSS Technical Integration Committee (see report at http://www.anss.org/ticplan/) and the ANNS Pacific Northwest Region Siting Advisory Committee Meeting (see http://www.ess.washington.edu/SEIS/ANSS/), as well as several meetings of Cascadia Regional Earthquake Workgroup (CREW) subcommittees.
  • PNSN representatives participated in national level ANSS committees and activiites throughout the year, and attended a wide variety of other meetings related to earthquake hazards, preparedness, and related information and outreach.
  • The PNSN was especially well represented at the April meeting of the Seismological Society of America, with individual or shared authorship of numerous posters and presentations.
  • Tony Qamar, Washington State Seismologist, has been appointed to the newly reconstituted Seismic Safety Committee of the Washington State Emergency Management Council. Dr. Qamar has been appointed chairman of the Information and Technology Subcommittee.

    ACKNOWLEDGMENTS

    Seismic stations, telemetry links, and data acquisition equipment were maintained by Jim Ramey and Allen Strelow at the UW, Patrick McChesney (stationed at CVO in Vancouver, Washington), Pat Ryan (of the University of Oregon in Eugene, Oregon), and Don Hartshorn (of Pacific Northwest National Labs in Richland, WA). Bill Steele provided information to the public, while Amy Wright handled routine data analysis and archiving of digital trace data in UW2 format. George Thomas, Amy Lindemuth, Lynn Hultgrien and Sue Sweet worked on strong motion instrumentation and software. Ruth Ludwin wrote reports, maintained the PNSN web-pages, and handled administrative tasks. The University of Oregon (UO) installed and maintained stations and telemetry links in central Oregon, and operated an earthworm node to transmit data to the University of Washington.


    APPENDIX 1
    PNSN Quarterly Reports
    .br
    01-A, 01-B, 01-C, and 01-D

    APPENDIX 3
    Reprint of:
    .br
    Preliminary Report on the Mw=6.8 Nisqually, Washington Earthquake of 28, February 2001
    2001, SRL V. 72, N. 3, pp. 352-361.