Mount Redoubt Erupts

Mount Redoubt, about 180km southwest of Anchorage in Alaska, USA, erupted on 22^nd March 2009, since which the Alaska Volcano Observatory has recorded several further explosions, the largest on 23^rd March at 4:31am. These latest eruptions represent the most emphatic seismic activity on the mountain since 14^th December 1989, when the volcano last erupted, activity continuing for more than six months.

This photo, taken in a south-facing direction on 4^th May 1990 by R. McGimsey, shows geologist John Ewert using a laser survey instrument to measure distances to reflective prisms or targets installed on the flanks of the distant volcano. Minute changes in distance to the targets can indicate ground deformation that may be related to movement of subsurface magma. For more information on the recent seismic activity at Mount Redoubt visit the Alaska Volcano Observatory website (1).

Grand Canyon Studies

GPS data collection at Grand Canyon-Colorado River site 9, downstream from Blacktail Canyon, Lat. 36º 14' 13.93649" N, Long. 112º 27' 56.95757" W, Ellip. Ht. 641.727m. This fieldwork was done in 2002 in support of an USGS investigation into the applicability of National Civil Application Program data for monitoring and mapping ecosystem change resulting from seasonal fluctuation in the Colorado River, and to supplement two other research studies conducted in the Grand Canyon, one on airborne digital sensors system and another on GPS-aided inertial technology for direct geopositioning.