Studies of Seismicity near the Active Volcano Mt. Spurr

• Main Authors: Olivas^, Sarah J., Doser*, Diane I.
• Format: Text
• Language: unknown
• Published: ScholarWorks@UTEP 2011
• Subjects: Seismicity; Active Volcano; Mt. Spurr; Environmental Sciences; Ecology and Evolution; and Geology; Geology; Geophysics and Seismology; Anchorage; Pacific; glacier; Yakutat; Alaska
• Online Access: https://scholarworks.utep.edu/couri_abstracts/24; https://scholarworks.utep.edu/cgi/viewcontent.cgi?article=1018&context=couri_abstracts

Seismicity patterns and fault orientations can indicate local stress fields related to volcanic eruptions. There have been many moderate magnitude, shallow earthquakes occurring in the Strandline Lake region about 100km from Anchorage, Alaska near the active volcano, Mt. Spurr. Previous researchers have found that the local stress under Mt. Spurr, before and after its 1992 eruption (1992-1997), differed from the regional stresses, which are related to subduction of the Pacific Plate and Yakutat micro plate. We are analyzing location and patterns of earthquakes occurring since 1998 to determine if more recent seismicity is similar to that occurring before or after the 1992 eruption. We obtained about 933 events using the Alaska Earthquake Information Center website (AEIC). Two major groups of earthquakes were found: one directly linked to volcanic activity, and the other possibly associated with the active Capps Glacier Fault. Seismic arrival times from the AEIC will be used to relocate the positions of recent earthquakes more precisely. The relocations will then be compared to geologic and other geophysical information. First motions of seismic waves will be used to help determine orientation of small faults that produced earthquakes. Seismicity patterns and fault orientations will tell us if the stress field since 1998 is the same as pre-eruption or post-eruption.