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Early magnitude and potential damage zone estimates for the great Mw 9 Tohoku-Oki earthquake

Colombelli, Simona and Zollo, Aldo and Festa, Gaetano and Kanamori, Hiroo (2012) Early magnitude and potential damage zone estimates for the great Mw 9 Tohoku-Oki earthquake. Geophysical Research Letters, 39 (22). Art. No. L22306. ISSN 0094-8276. doi:10.1029/2012GL053923.

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The Mw 9.0, 2011 Tohoku-Oki earthquake has reopened the discussion among the scientific community about the effectiveness of earthquake early warning for large events. A well-known problem with real-time procedures is the parameter saturation, which may lead to magnitude underestimation for large earthquakes. Here we measure the initial peak ground displacement and the predominant period by progressively expanding the time window and distance range, to provide consistent magnitude estimates (M = 8.4) and a rapid prediction of the potential damage area. This information would have been available 35 s after the first P-wave detection and could have been refined in the successive 20 s using data from more distant stations. We show the suitability of the existing regression relationships between early warning parameters and magnitude, provided that an appropriate P-wave time window is used for parameter estimation. We interpret the magnitude under-estimation as a combined effect of high-pass filtering and frequency dependence of the main radiating source during the rupture process.

Item Type:Article
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Kanamori, Hiroo0000-0001-8219-9428
Additional Information:© 2012 American Geophysical Union. Received 19 September 2012; revised 24 October 2012; accepted 24 October 2012; published 30 November 2012. This work was financially supported by Dipartimento della Protezione Civile (DPC) through AMRA scarl within the research contracts REAC and RELUIS 2010–2013, and by EU-FP7 in the framework of project REAKT. We are grateful to Anthony Lomax and to an anonymous reviewer for their valuable and constructive comments.
Funding AgencyGrant Number
Dipartimento della Protezione Civile (DPC)REAC
Dipartimento della Protezione Civile (DPC)RELUIS 2010–2013
European Union (EU) FP7REAKT
Issue or Number:22
Record Number:CaltechAUTHORS:20130111-145609402
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Official Citation:Colombelli, S., A. Zollo, G. Festa, and H. Kanamori (2012), Early magnitude and potential damage zone estimates for the great Mw 9 Tohoku-Oki earthquake, Geophys. Res. Lett., 39, L22306, doi:10.1029/2012GL053923
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36332
Deposited By: Tony Diaz
Deposited On:16 Jan 2013 19:17
Last Modified:09 Nov 2021 23:21

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