Surface Rupture of the November 2002 M7.9 Denali Fault Earthquake, Alaska, and Comparison to Other Strike-Slip Ruptures

• Published in: Earthquake Spectra
• Main Authors: Haeussler, P. J., Schwartz, D. P., Dawson, T. E., Stenner, H. D., Lienkaemper, J. J., Cinti, F. R., Montone, P., Sherrod, B., Craw, P.
• Other Authors: Haeussler, P. J.; U.S. Geological Survey, Anchorage, AK, Schwartz, D. P.; U.S. Geological Survey, Menlo Park, CA, Dawson, T. E.; U.S. Geological Survey, Menlo Park, CA, Stenner, H. D.; U.S. Geological Survey, Menlo Park, CA, Lienkaemper, J. J.; U.S. Geological Survey, Menlo Park, CA, Cinti, F. R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia, Montone, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia, Sherrod, B.; U.S. Geological Survey, Seattle, WA, Craw, P.; Division of Geological and Geophysical Surveys, Fairbanks, AK, U.S. Geological Survey, Anchorage, AK, U.S. Geological Survey, Menlo Park, CA, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia, U.S. Geological Survey, Seattle, WA, Division of Geological and Geophysical Surveys, Fairbanks, AK
• Format: Article in Journal/Newspaper
• Language: English
• Published: Earthquake Engineering Research Institute 2004
• Subjects: Earth crust; earthquakes; faulting; slip; pipelines; Denali fault; Susitna Glacier fault; Totschunda fault; Surface rupture; November 3; 2002 M7.9 earthquake; Alaska; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology; glacier
• Online Access: http://hdl.handle.net/2122/579; https://doi.org/10.1193/1.1775797

On November 3, 2002, a moment-magnitude (Mw) 7.9 earthquake produced 340 km of surface rupture on the Denali fault and two related faults in central Alaska. The rupture, which proceeded from west to east, began with a 40-km-long break on a previously unknown thrust fault. Estimates of surface slip on this thrust were 3-6 m. Next came the principal surface break, along 220 km of the Denali fault. There, right-lateral offset averaged almost 5 m and increased eastward to a maximum of nearly 9 m. Finally, slip turned southeastward onto the Totschunda fault, where dextral offsets up to 3 m continued for another 70 km. This three-part rupture ranks among the longest documented strike-slip events of the past two centuries. The surface-slip distribution supports and clarifies models of seismological and geodetic data that indicated initial thrusting followed by rightlateral strike slip, with the largest moment release near the east end of the Denali fault. The Denali fault ruptured beneath the Trans-Alaska oil pipeline. The pipeline withstood almost 6 m of lateral offset, because engineers designed it to survive such offsets based on pre-construction geological studies. The Denali fault earthquake was typical of large-magnitude earthquakes on major intracontinental strike-slip faults, in the length of the rupture, the multiple fault strands that ruptured, and the variable slip along strike. Published 565-578 open