ANNUAL TECHNICAL REPORT

USGS Joint Operating Agreement 1434-HQ-98-AG-01937
"PACIFIC NORTHWEST SEISMOGRAPH NETWORK (PNSN) OPERATIONS"

SUMMARY
This is the 1999 annual technical report for USGS Joint Operating Agreement 1434-HQ-98-AG-01937 "Pacific Northwest Seismograph Network (PNSN) Operations" This agreement covered network operations in western Washington and Oregon, routine data processing, and preparation of bulletins and reports. 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 1999, an overview of our public information program, and a summary of 1999 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 1999.

CURRENT INITIATIVES

Introduction

The PNSN is currently in the process of upgrading operations, including extensive changes to data recording, exchange, and processing systems. 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 compatibility

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. In 1998 the PNSN installed three CREST-compatible (but not CREST equipment) stations (real-time, broadband, and strong-motion; ERW, ELW, and SP2) installed. Two stations, RWW and GNW, with full CREST equipment were installed in Washington during 1999. An EARTHWORM node was configured, tested, and shipped to Eugene, Oregon, and installation of two CREST stations in Oregon is expected in early 2000.

PNSN Strong Motion Program and RACE (Rapid Alerts for Cascadia Earthquakes) System

Since May of 1996 the the Pacific Northwest Seismograph Network (PNSN) has been upgrading strong-motion instrumentation in urban areas. The strong-motion update began in the Seattle area, and in 1999 was extended into Portland, Oregon. A total of twenty stations, most of them real-time, are currently operating in Washington and Oregon. Table 1C gives locations, instrumentation, and telemetry methods. Several of the strong-motion sites also have broad-band three-component sensors.

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 prototype mode at five emergency management agencies in Washington and Oregon.

In order to continue development of both the strong-motion network and the RACE system, the PNSN is creating a "research associates" plan which will make it easier to form partnerships with public or private groups that need immediate strong motion information from critical facilities. In addition, the PNSN is seeking additional funding from the state of Washington to support ongoing and enhanced operations.

EARTHWORM Progress Report

Work on EARTHWORM and PNSN Y2K compatibility was ongoing throughout 1999. Over the year, extensive work was done on basic EARTHWORM software and PNSN analysis and distribution software to make them Y2K compliant. The millennial rollover was completed without significant problems.

OPERATIONS

Seismometer Locations and Network Maintenance

By the end of 1999, the PNSN EARTHWORM SYSTEM was digitally recording 246 channels of real-time or near-real-time seismic data Stations available include a total of 141 short-period analog stations (7 of them received from other networks via EARTHWORM), 11 broad-band and 17 strong-motion stations.

The majority of sites have a single short-period vertical, component which is telemetered continuously in analog form to the UW. This contract (JOA 1434-HQ-98-AG-01937) supports 92 short-period sites (some with multiple components) and operation of 17 strong motion and 8 broad-band stations, plus horizontal seismometers with Wood-Anderson-response at station SEA on the campus of the University of Washington. The supported stations cover much of western Washington and Oregon, including the volcanos of the central Cascades.

Additional stations funded by other contracts are also used in event locations. The locations of all stations operating at the end of 1999 are given in Tables 1A (short-period), 1B (broad-band), and 1C (strong motion) and shown in Fig. 1. Quarterly reports provide additional details of station operation. Quarterly reports from January 1, 1999 through December, 1999 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 stations with continuous telemetry to the PNSN lab which were operated by the PNSN at the end of the reporting period. Table 1B lists broad-band stations in the Pacific Northwest, and Table 1C lists strong-motion, three component stations. The first column in Tables 1A and 1B gives the 3-letter station designator. Column 2 designates the funding agency; operations of stations marked by a % symbol were fully supported by USGS joint operating agreement 1434-HQ-98-AG-01937 Stations designated # were installed or are maintained by the USGS, but are telemetered to the PNSN lab. Stations from the Northern California network, received over internet, are marked "C". Data from some of the broad-band stations operated under other support are archived at the PNSN. Remaining 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 operating during the fourth quarter 1999
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
 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
 BRV   +  46 29 07.2  119 59 28.2  0.920  Black Rock Valley
 BVW   +  46 48 39.6  119 52 59.4  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
 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
 DBO      43 07 09.0  123 14 34.0  0.984  Dodson Butte, Oregon
 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
 FBO   %  44 18 35.6  122 34 40.2  1.080  Farmers Butte, Oregon
 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
 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.
 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.
 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
 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
 KEB   C  42 52 20.0  124 20 03.0  0.818  CAL-NET
 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
 KSX   C  41 49 51.0  123 52 33.0       CAL-NET
 KTR   C  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   C  41 36 35.2  122 37 32.1  1.769  CAL-NET
 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
 LON   %  46 45 00.0  121 48 36.0  0.853  Longmire (BB,LONLZ)
 LVP   %  46 04 06.0  122 24 30.0  1.170  Lakeview Peak
 MBW   %  48 47 02.4  121 53 58.8  1.676  Mt. Baker
 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 Center
 OHW   %  48 19 24.0  122 31 54.6  0.054  Oak Harbor
 ONR   %  46 52 37.5  123 46 16.5  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
 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
 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
 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
 RSW   +  46 23 40.2  119 35 28.8  1.045  Rattlesnake Mt. (East)
 RSU   %  46 51 12.0  121 45 47.0  4.440  Rainier summit
 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
 SEP   #  46 12 00.7  122 11 28.1  2.116  September lobe, Mt. St. Helens Dome
 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.
 SND   %  46 12 45.0  122 11 09.0  1.800  St. Helens Microphone, unrectified
 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
 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
 TKO   %  45 22 16.7  123 27 14.0  1.024  Trask Mtn, Oregon
 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
 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
 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
 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
 VRC   %  42 19 47.2  122 13 34.9  1.682  Rainbow Creek, 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
 WG4   +  46 01 49.2  118 51 21.0  0.511  Wallula Gap
 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

Table 2B lists broad-band, three-component stations operating in Washington and Oregon that provide data to the PNSN.

TABLE 1B
Broad-band three-component stations operating at the end of the fourth quarter 1999. Symbols are as in Table 2A.
STA  F  LAT  LONG  EL  NAME
 CHE      45 21 16.0  122 59 19.0  0.436  Chehalem, Oregon (Operated by UO)
 COR      44 35 08.5  123 18 11.5  0.121  Corvallis, Oregon (IRIS station, Operated by OSU)
 ELW   %  47 29 38.8  121 52 21.6  0.267  Echo Lake, WA (operated by UW)
 ERW   %  48 27 14.4  122 37 30.2  0.389  Mt. Erie, WA (operated by UW)
 GNW   %  47 33 51.8  122 49 31.0  0.165  Green Mountain, WA (CREST - operated by UW)
 HAWA     46 23 32.3  119 31 57.2  0.367  Hanford Nike (USGS-USNSN)
 LON   %  46 45 00.0  121 48 36.0  0.853  Longmire, WA (operated by UW)
 LTY   %  47 15 21.2  120 39 53.3  0.970  Liberty, WA (operated by UW)
 NEW      48 15 50.0  117 07 13.0  0.760  Newport Observatory (USGS-USNSN)
 OCWA     47 44 56.0  124 10 41.2  0.671  Octopus Mtn. (USGS-USNSN)
 PIN      43 48 40.0  120 52 19.0  1.865  Pine Mt. Oregon (operated by UO)
 RAI      46 02 25.1  122 53 06.4  1.520  Trojan Plant, Oregon (OSU)
 RWW   %  46 57 50.1  123 32 35.9  0.015  Ranney Well (CREST - operated by UW)
 SP2   %  47 33 23.3  122 14 52.8  0.030  Seward Park, Seattle (operated by UW)
 TTW   %  47 41 40.7  121 41 20.0  0.542  Tolt Reservoir, WA (operated by UW)
 WVOR     42 26 02.0  118 38 13.0  1.344  Wildhorse Valley, Oregon (USGS-USNSN)


Table 2C 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 recording system,
  • 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.
  • The "TELEMETRY" field indicates the type of telemetry used to recover the data. D = dial-up,
  • L = continuously telemetered via dedicated lease-line telephone lines,
  • L-PPP = continuously telemetered via dedicated lease-line telephone lines using PPP protocol
  • I = continuously telemetered via Internet,
  • E = continuously telemetered via an Internet earthworm system

    Strong-motion three-component stations operating at the end of the fourth quarter 1999. Symbols are as in Table 2A. STA F LAT LONG EL NAME SENSORS TELEMETRY ALST % 46 6 31.2 123 01 47.4 0.000 Alston, Oregon BPA A20 E CSO # 45 31 01.0 122 41 22.5 0.036 Canyon Substation, Oregon FBA23 D ERW % 48 27 14.4 122 37 30.2 0.389 Mt. Erie, WA A,BB L ELW % 47 29 38.8 121 52 21.6 0.267 Echo Lake, WA A,BB L GNW % 47 33 51.8 122 49 31.0 0.165 Green Mountain, WA (CREST) EPI,BB3 L-PPP HAO # 45 30 33.1 122 39 24.0 0.018 Harrison Substation, Oregon FBA23 D KEEL % 45 33 0.0 122 53 44.40 0.000 Keeler, Oregon BPA A20 E MBPA % 47 53 56.6 121 53 20.2 0.186 Monroe BPA A20 L,D MPL % 47 28 08.2 122 11 06.2 0.122 Maple Valley A L,D NOWS % 47 41 12.0 122 15 21.2 0.00 NOAA, Bldg 3 A20 I QAW % 47 37 53.2 122 21 15.0 0.140 Queen Anne A L RAW % 47 20 14.0 121 55 57.6 0.208 Raver BPA A L,D RBO # 45 32 27.0 122 33 51.5 0.158 Rocky Butte, Oregon FBA23 D ROSS % 45 39 46.2 122 39 37.0 0.100 Ross BPA A20 L,E RWW % 46 57 50.1 123 32 35.9 0.015 Ranney Well (CREST) EPI,BB3 L-PPP SEA % 47 39 18.0 122 18 30.0 0.030 Seattle A,BB L,D SP2 % 47 33 23.3 122 14 52.8 0.030 Seward Park, Seattle A,BB L TBPA % 47 15 28.1 122 22 05.9 0.002 Tacoma WA BPA A L,D TKCO % 47 32 12.7 122 18 01.5 0.005 King Co EOC A20 I UPS % 47 15 56.1 122 28 58.4 0.113 U. Puget Sound A D,I

    Data Processing

    The seismograph network operated by the University of Washington consists of small numbers of broad-band and strong-motion sensors, plus over 130 short-period, vertical component, real-time-telemetered seismographic stations. Using real-time-telemetry data, the PNSN seismic recording system operates in an `event triggered' mode, recording data at 100 samples per sec. per channel. Data from stations with other telemetry systems are retrieved and integrated with the event-triggered data. 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 teleseisms, regional events, and all locatable local events. Each trace data file has an associated `pickfile' which includes arrival times, polarities, coda lengths, and other data.

    In 1998, EARTHWORM replaced the SUNWORM system as the main PNSN data-acquisition system. The SUNWORM system continues to operate as a backup system. We continue to use our UW2 format data and the same analysis tools in place for the past several years.

    Most PNSN broad-band stations record continuously, as well as having the ability to trigger and record on-site. Stations LTY, and LON record digitally on-site, and data are retrieved via dial-up modem. Stations RWW and GNW used to be similar, but have been upgraded to CREST equipment, and no longer record on-site. We also receive data for selected events via Auto-DRM from U.S. National Seismograph Network (USNSN) stations NEW; in north-eastern Washington, and WVOR; in south-eastern Oregon. Data for specific events are provided to the PNSN from broad-band stations PIN, DBO, COR, and RAI (operated by Oregon State University and the University of Oregon).

    Broad-band data in "raw" formats are stored on ongoing "network-archive" backups along with all unedited network-trigger trace data. Broadband data are also archived in merged and edited UW2 format on our "Master Event" tapes along with data from the PNSN short-period network, Our "Master Event" files are also translated to IRIS-SEED format and submitted to the IRIS Data Management Center for archive and distribution. All of our "Master Event" tapes of seismic trace data from 1980-1998 have now been reformatted to the IRIS-SEED format and submitted to the IRIS Data Management Center, where they are made available through the standard request mechanisms of the IRIS data-base system.

    Oregon State University (OSU) provides broad-band data for some events from stations COR and RAI. The University of Oregon (UO) provides broad-band data for some events (from stations PIN and DBO. Phase data for earthquakes in northern Washington and southern British Columbia are exchanged with the Canadian Pacific Geoscience Centre promptly for significant events. We also exchange data occasionally with the Montana Bureau of Mines, Boise State University, and CALNET. 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.

    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 1999 which were reported felt. For comparison purposes, Table 3 gives information on seismic activity recorded at the PNSN annually since 1980. During this reporting period there were 20 earthquakes reported felt west of the Cascades in Washington, ranging in magnitude from 1.8 to 5.1 (body wave magnitude 5.5). No earthquakes were felt in Washington east of the Cascades. In Oregon, 10 earthquakes were reported felt.

    The largest earthquake in Washington this year was a coda magnitude 5.1 (body wave magnitude 5.5) earthquake on July 3 UTC (July 2 6:43 PM PDT). It occurred at a depth of about 41 km, about 8 km north of Satsop, WA. The July 3 UTC earthquake was felt throughout most of western Washington and northwest Oregon, and in parts of southwest British Columbia, Canada.

    The maximum acceleration recorded during the July 3 UTC earthquake was 8%g at Wynoochee dam. The estimated acceleration at the epicenter is 17%g. The strongest shaking corresponded to a level of about VI on the Modified Mercalli Intensity scale. Structural damage included cracked chimneys and broken windows. The three-story Grays Harbor County Courthouse, built in 1910 and located in Montesano, suffered extensive structural damage to its cupola. Interior walls were also cracked. The Montesano fire station, built around 1979, also suffered structural damage. In Aberdeen, some structural cracks of walls and beams were reported. In addition, power outages and water main breaks occurred. The wood-framed roof of a furniture store collapsed.

    TABLE 2
    Felt Earthquakes during 1999
    DATE-(UTC)-TIME  LAT(N)  LON(W)  DEPTH  MAG  COMMENTS
    yy/mm/dd hh:mm:ss    deg.    deg.     km      
    99/01/04 15:10:37   47.20N  122.27W   22.2  3.2      12.5 km ESE of Tacoma, WA
    99/01/11 13:48:46   45.32N  121.65W    7.5  2.5       6.5 km SSE of Mount Hood, OR
    99/01/11 16:54:11   45.32N  121.65W    7.0  3.0       6.6 km SSE of Mount Hood, OR
    99/01/11 22:04:14   45.31N  121.65W    6.9  3.2       7.0 km SSE of Mount Hood, OR
    99/01/14 11:56:47   45.33N  121.66W    7.6  3.2       5.4 km SSE of Mount Hood, OR
    99/01/14 16:13:42   45.32N  121.66W    5.9  3.0       6.2 km SSE of Mount Hood, OR
    99/01/31 11:33:32   42.77N  124.68W   25.0  2.6      76.4 km SSW of Coos Bay, OR
    99/02/24 16:45:17   45.13N  122.66W   35.7  2.7      14.6 km   S of Canby, OR
    99/03/16 13:39:49   48.48N  121.80W    0.0  1.8       7.3 km  SW of Concrete, WA
    99/04/03 17:29:22   48.35N  123.24W   46.3  3.1      11.4 km  SE of Victoria, BC
    99/04/11 00:05:37   48.19N  122.75W   20.3  2.6      39.5 km  SW of Mount Vernon, WA
    99/04/17 07:31:09   46.86N  121.95W    9.8  3.6      15.2 km   W of Mount Rainier
    99/06/29 04:51:43   48.94N  123.05W   19.6  2.7      20.6 km   S of Vancouver,BC
    99/06/29 13:31:46   48.91N  123.05W   20.1  2.2      23.4 km   S of Vancouver,BC
    99/07/02 05:22:19   47.36N  122.39W   27.1  3.1      14.9 km   N of Tacoma, WA
    99/07/03 01:43:54   47.07N  123.46W   40.7  5.1       8.0 km   N of Satsop, WA
    99/07/09 07:45:42   47.06N  123.46W   39.8  2.1       6.8 km   N of Satsop, WA
    99/07/16 05:58:24   45.65N  122.77W   19.7  2.3      17.7 km  NW of Portland, OR
    99/07/16 05:59:59   45.65N  122.77W   18.9  2.3      17.7 km  NW of Portland, OR
    99/07/16 21:34:03   45.64N  122.76W   18.1  3.1      17.2 km  NW of Portland, OR
    99/08/25 17:48:43   47.75N  121.86W    7.4  2.0       9.5 km ENE of Duvall, WA
    99/09/03 07:16:18   47.50N  123.12W    0.0  2.9      38.2 km   W of Bremerton, WA
    99/09/05 18:01:36   47.16N  123.12W   46.5  2.8      22.3 km  NW of Olympia, WA
    99/09/20 11:16:54   47.60N  121.76W   16.9  2.8      10.4 km ENE of Fall City, WA
    99/10/03 10:50:29   46.54N  121.81W    3.7  2.5      28.2 km   W of Goat Rocks
    99/11/16 20:51:16   47.86N  122.00W   19.7  2.5       2.7 km WNW of Monroe, WA
    99/11/21 11:33:45   45.46N  122.07W   13.6  2.6      31.3 km WNW of Mount Hood, OR
    99/11/25 14:46:15   45.11N  122.78W   28.3  3.4       6.5 km ESE of Woodburn, OR
    99/11/29 04:04:15   42.31N  122.01W    7.0  3.4      22.2 km WNW of Klamath Falls, OR
    99/12/11 12:53:40   48.53N  123.24W   49.2  3.7      14.4 km NNE of Victoria, BC
    99/12/25 06:49:58   48.70N  125.91W   10.0  4.0      49.0 km   S of Tofino, BC
    99/12/25 07:01:49   48.62N   125.93W  10.0  3.2      58.3 km   S of Tofino, BC
    

    Emergency Notification

    The RACE system, discussed earlier, is a pager-based alarm system that updates earthquake locations mapped on a PC screen. When a "significant" event (magnitude 2.9 or larger) is located by the PNSN automatic systems, 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.

    TABLE 3
    Annual counts of events recorded by the PNSN, 1980-1999
    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
    

    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 most frequently requested information is our "recent earthquakes" list of Pacific Northwest earthquakes magnitude 2.0 or larger. It can be accessed in several ways; Table 4 shows the quarterly usage of our "recent earthquakes" list. Our list is also picked up, reformatted and offered on a wide variety of other web sites, so the number of people who access this information is much larger.
    TABLE 4
    Accesses of PNSN "Most recent earthquakes M>=2.0" list
    Quarterly Comparison
    Access Method  98-A  98-B  98-C  98-D  99-A  99-B  99-C  99-D
    Finger Quake  124,000  113,367  122,429  113,430  105,557  99,451  87,981  111,000
    World-Wide-Web  50,000  55,600  49,000  47,400  41,700  34,000  64,000  42,000
    

    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, including a frequently updated "recent earthquakes" message. 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 very busy one for the PNSN. We organized or participated in several very special events:

  • The PNSN, along with UW Geological Sciences and the USGS co-sponsored an Urban Hazards Workshop to review the current status of a variety of geologic mapping and geophysical exploration projects which are providing detailed geologic-hazards information that can be used for land-use and code planning. The invitation-only meeting was attended by about 200 people from the scientific, government and business communities.
  • The PNSN hosted the 94th Annual Meeting of the Seismological Society of America, held May 3-5 at the Seattle Center. More than 375 seismologists attended. The meeting had a special focus on current and ongoing work on the Pacific Northwest, including results from the 1998 SHIPS experiment. A special Public Forum on PNW Earthquake Hazards was attended by more than 250 scientists and members of the public.
  • The PNSN organized natural hazards information fairs for two "Disaster Saturday" presentations (Sponsored by Seattle Project Impact). USGS and UW scientists working in the Puget Sound region presented their work on earthquake hazards to the public.
  • The second phase of the U.S. Geological Survey's (USGS) SHIPS (Seismic Hazards in Puget Sound) active seismic experiment took place from September 20-22. This phase consisted of about 40 explosions at 33 shot-points along a 100 km long east-west line running from the Cascade foothills to the Olympic Peninsula. Seismic waves were generated by explosions in boreholes. Waves reflected from underground layers were recorded by about 1,000 seismic recorders spaced at 100 meter intervals along the same line, and also by the permanent stations of the PNSN.
  • PNSN representatives continued their involvement with CREW (the \fBCascadia Regional Earthquake Workgroup\fR) and \fBProject Impact\fR. Both these projects are aimed at mitigation of earthquake damage, and the PNSN role in providing information on geologic hazards is crucial to the education and mitigation effort.

    Our World-Wide-Web site is an important element of our outreach, handling around 600,000 public contacts/quarter. An additional 800,000 Web-contacts/quarter are made through other earthquake-related pages hosted on the PNSN web-server; including the "CREW" Web-site, the very popular "Tsunami!" site, the "seismosurfing" page, and the "Council for the National Seismic System (CNSS)" Web-site

    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 Sandra Corso handled routine data analysis and archiving of digital trace data in UW2 format. Dr. Peter Lombard worked on EARTHWORM and PNSN Y2K compliance. George Thomas worked on various projects related to strong motion instrumentation and software. Ruth Ludwin wrote reports, maintained the PNSN web-pages, and handled administrative tasks. Peter Burkholder modified SEED routines and archived data in SEED format. Oregon State University (OSU) provided broad-band data from stations COR and RAI, which is archived with PNSN trace-data files. The University of Oregon (UO) provided broad-band data from stations PIN and DBO.



    APPENDIX 1
    PNSN Quarterly Reports
    .br
    99-A, 99-B, 99-C, and 99-D