Publication Date:
2012-01-24
Description:
Many large earthquakes are preceded by one or more foreshocks, but it is unclear how these foreshocks relate to the nucleation process of the mainshock. On the basis of an earthquake catalog created using a waveform correlation technique, we identified two distinct sequences of foreshocks migrating at rates of 2 to 10 kilometers per day along the trench axis toward the epicenter of the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake in Japan. The time history of quasi-static slip along the plate interface, based on small repeating earthquakes that were part of the migrating seismicity, suggests that two sequences involved slow-slip transients propagating toward the initial rupture point. The second sequence, which involved large slip rates, may have caused substantial stress loading, prompting the unstable dynamic rupture of the mainshock.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kato, Aitaro -- Obara, Kazushige -- Igarashi, Toshihiro -- Tsuruoka, Hiroshi -- Nakagawa, Shigeki -- Hirata, Naoshi -- New York, N.Y. -- Science. 2012 Feb 10;335(6069):705-8. doi: 10.1126/science.1215141. Epub 2012 Jan 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Earthquake Research Institute, The University of Tokyo, Tokyo, Japan. akato@eri.u-tokyo.ac.jp〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22267578" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink