HR: 0800h
AN: G21B-1269    [Abstracts]
TI: Update on Plate Boundary Observatory (PBO) Activities in the PNW Region
AU: * Hafner, K
EM: hafner@unavco.org
AF: UNAVCO/PBO - PNW regional Office, 3110 Airport Rd., #3, Ellensburg, WA 98926
AB: As of September 2005 The Plate Boundary Observatory (PBO), part of the larger NSF-funded EarthScope project, is completing year 2 in the installation phase of 875 continuously operating GPS instruments in the Western United States. The Pacific Northwest (PNW) region will install 149 continuous GPS stations by the end of 2008. These sites are distributed along the fore and back-arc of the Cascadia Subduction Zone and at Mt. St. Helens. At the end of year 2, the PNW Region of PBO reached its year two installation goal of 41 GPS stations. The scientific emphasis priority during year 2 was to capture Episodic Tremor And Slip (ETS) on the Cascadia Subduction Zone by installing GPS sites stations in southern Oregon, on the Olympic peninsula (where four strainmeters were also installed) and on Mt. St. Helens. Work on Mt. St. Helens volcano included the installation of five stations in October 2004. Data analyses showed that one of the PBO sites located high on the SE flank of the volcano moved 4 cm SE between mid-November 2004 and January 2005. This was most likely due to growth of the new lava dome against the SE crater wall. As a result of this activity, the PBO obtained two additional permits from the USFS, and these sites were installed at the beginning of February, 2005. PBO has continued to work with the USFS to complete the permitting process for nine more GPS locations on the flanks of the volcano. Due to required cultural and botanical surveys, these permits are not expected to be approved until at least June of 2006. The pace of installations will increase during year three of the project where scientific priortity will shift to installing stations in southern Oregon and the backarc/Basin and Range transition zone. For the PNW region, this translates into approximately 4 new GPS installations per month. In addition to continued construction, activities will focus on completing reconnaissance and permit submittal activities for all sites proposed to be located on Federal and State Lands, and operations and maintenance of installed stations. We plan to have all of these permits in the approval process by the end of September of 2006.
UR: http://pbo.unavco.org
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005