UNAVCO field crews have returned to Augustine Volcano to install five permanent EarthScope GPS stations. These stations will add to the data footprint from those installed by UNAVCO exactly two years ago in 2004. Since then, Augustine has experienced some significant activity starting this year in mid-January with a series of explosions and erupts, sending plumes of ash more than 40,000 feet into the air. Two of the five EarthScope GPS stations were completely destroyed, however not before capturing priceless data from the volcano's fierce rumblings. UNAVCO is back on Augustine to install additional stations as recommended by the PBO Magmatic Site Selection Committee. The committee proposed the installation of up to 8 GPS sites and 4 tiltmeter sites, co-located with either new or existing GPS sites on Augustine volcano. Given this recommendation, UNAVCO is installing a total of 5 GPS stations during this expedition: 3 in distal locations and 2 on the volcano's flanks. The GPS stations installed in 2004 are positioned primarily around the top half of the volcano; adding stations in distal locations closer to the coast could potentially identify uplift months before it is seen on the flanks of the volcano enabling scientists to see deformation take place from a deeper seated source as the magma migrates upwards. The proposed distal sites are at low elevation where deep snow accumulations are unlikely. As stated in a recent Magmatic Site Selection Committee report:
"We believe that this level of instrumentation would provide an unparalleled opportunity to observe active magmatic processes within the shallow crust. This may be the best opportunity for PBO to catch a large explosive eruption during its planned life."With approximately 3000 pounds of equipment and food packed into three float planes, a total of 6 UNAVCO employees arrived on Augustine Volcano on August 31, 2006, just in time to sling several loads of the gear up to base camp from the beach, set up sleeping arrangements for the night, and have a hot dinner with a group from AVO who arrived on the volcano a few days earlier for another project. Since arrival the weather has been fairly nice during the day with clear skies for easy navigation around the volcano. Volcanic activity remains calm with the exception of two small avalanches in the middle of the night, one exposing red incandescence on the north side of Augustine. So far drilling has begun on two sites: AV17 (near the coast on the northwest side of the volcano) and AV18. Located on the north flank of the volcano on a prominent lava flow most likely from the 1986 eruption, AV18 is in the same area that AV03 was prior to being destroyed by the eruptions. Damages to AV04, now our highest site on the volcano, are repaired and the station is back online with a replaced antenna and dome and rewired solar panels. Building and staging continue on base camp in preparation for full-force installation activities after the arrival of two additional UNAVCO field engineers this evening.