Pacific Northwest Geodetic Array
Central Washington University

PANGA Rapid Response

The Nisqually earthquake which struck the Puget Sound area on February 28, 2001, poses the first opportunity to study an earthquake in the Pacific Northwest using GPS geodesy. The CWU Geodesy Laboratory and PANGA Data Analysis Facility has posted a elastic half-space dislocation model that shows the predicted co-seismic displacements for the Nisqually earthquake.

With help from USGS/SCIGN and UNAVCO, PANGA installed four continuous GPS stations in Puget Sound region. Within a few weeks, three additional sites will be installed near Blyn Mountain, Wynochee Lake and Tiger Mountain. Click here for rapid deployment plan map. We have recieved NSF and support from Trimble Navigation for the continuous GPS deployment.

Click on The February 28, 2001 Nisqually Earthquake: GPS Geodesy and quantifying seismic hazard [4.9 MB, PDF] for a copy of M. Miller's written testimony submittted to the Subcommittee on Research, The Committee on Science United States House of Representatives on the recent Nisqually Earthquake and Federal Efforts to Reduce Earthquake Hazards.

Two days following the earthquake, CWU undergraduates have initiated survey mode GPS observations of marks occupied by UW and RPI during the last year. These observations will add density to the post-seismic velocity field and provide baseline measurements for possible post-seismic transient deformation.

USGS Crustal Strain Project personnel from Menlo Park are reoccupying a dense profile of stations that extends from the coast near Grays Harbor to Olympia. These stations have well-determined velocities from recent observations, and will form an important constraint on co-seismic deformation.

As data continue to come in from continuous GPS stations in the Pacific Northwest, the PANGA Data Analysis Facility will post a co-seismic displacement field for these well constrained stations and provide provide regional fiducial coverage for survey-mode observations.