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.
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.
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.
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.
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.
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)
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
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.
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
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
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.
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:
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
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.