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Crustal deformation and the seismic cycle across the kodiak islands, alaska
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Sauber, Jeanne Carver, Gary Cohen, Steven King, Robert |
| Copyright Year | 2005 |
| Description | The Kodiak Islands are located approximately 120 to 250 km from the Alaska-Aleutian Trench - and are within the southern extent of the 1964 Prince William Sound (M(sub w) = 9.2) earthquake rupture zone. Here we report new campaign GPS results (1993-2001) from northern Kodiak Island. The rate and orientation of the horizontal velocities, relative to a fixed North America, range from 25.3 plus or minus 1.4 mm/yr at N32.9 deg. W plus or minus 2.5 to 8.5 plus or minus 1.0 mm/yr at N59.7 deg. W plus or minus 6.5 deg. In addition to the northern Kodiak data, we analyzed data from three southern Kodiak Island stations. The inland stations from both the northern and southern networks indicate a counterclockwise rotation of the velocity vectors. These results are consistent with the hypothesis that the difference between the Pacific-North American plate motion and the orientation of the down going slab would lead to 4-8 mm/yr of left-lateral slip above the unlocked, down-dip portion of the main thrust zone. The northern and southern Kodiak geodetic data are consistent with a model that includes the viscoelastic response to (1) a downgoing Pacific plate interface that is locked at shallow depths, (2) local coseismic slip in the 1964 earthquake, and (3) interseismic creep down dip from the seismogenic zone. Based on the pre-1964 and post-1944 earthquake history, as well as the pattern of interseismic earthquakes across the plate boundary zone, we hypothesize that in southern Kodiak some strain is released in moderate to large earthquakes between the occurrences of great earthquakes like the 1964 event. |
| File Size | 6368562 |
| Page Count | 65 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20050156964 |
| Archival Resource Key | ark:/13960/t0tr0w15f |
| Language | English |
| Publisher Date | 2005-01-01 |
| Access Restriction | Open |
| Subject Keyword | Geophysics Viscoelasticity Deformation Plates Tectonics Geodesy Global Positioning System Time Dependence Geological Faults Prince William Sound Ak Seismology Aleutian Islands Us Crustal Fractures Alaska Digital Elevation Models Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
