Triggered Seismic Events Along the Eastern Denali Fault in Northwest Canada Following the 2012 M-W 7.8 Haida Gwaii, 2013 M-W 7.5 Craig, and Two M-W > 8.5 Teleseismic Earthquakes

• Main Authors: Aiken, Chastity, Zimmerman, Jessica P., Peng, Zhigang G., Walter, Jacob I.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: non-volcanic tremor; 9.0 tohoku-oki; tectonic tremor; alaska; magnitude; stresses; maule; geochemistry & geophysics; Canada; Indian; Klutlan Glacier; glacier; glacier*; Alaska
• Online Access: http://hdl.handle.net/2152/43229; https://doi.org/10.15781/T25Q4RP5V; https://doi.org/10.1785/0120140156

We conduct a systematic search for remotely triggered seismic activity along the eastern Denali fault (EDF) in northwest Canada, an intraplate strike-slip region. We examine 19 distant earthquakes recorded by nine broadband stations in the Canadian National Seismograph Network and find that the 2012 M-w 7.8 Haida Gwaii and 2013 M-w 7.5 Craig, Alaska, earthquakes triggered long duration (> 10 s), emergent tremor-like signals near the southeastern portion of the EDF. In both cases, tremor coincides with the peak transverse velocities, consistent with Love-wave triggering on right-lateral strike-slip faults. The 2011 M-w 9.0 Tohoku-Oki and 2012 M-w 8.6 Indian Ocean earthquakes possibly triggered tremor signals, although we were unable to locate those sources. In addition, we also identify many short-duration (< 5 s) bursts that were repeatedly triggered by the Rayleigh waves of the 2012 M-w 7.8 Haida Gwaii earthquake. Although we were unable to precisely locate the short-duration (< 5 s) events, they appear to be radiating from the direction of the Klutlan Glacier and from a belt of shallow historical seismicity at the eastern flank of the Wrangell-St. Elias mountain range. The fact that these events were triggered solely by the Rayleigh waves suggests a different source mechanism as compared with triggered tremor observed along the EDF and other plate boundary regions. National Science Foundation (NSF) Graduate Research Fellowship DGE-1148903 Achievement Rewards for College Scientists Foundation of Atlanta Summer Undergraduate Research Experience program of Southern California Earthquake Center NSF Career Grant EAR-0956051 USGS NEHRP G15AP00043 G15AP00044 Geological Sciences