Details

Autor(en) / Beteiligte

• Wang, Dun
• Kawakatsu, Hitoshi
• Zhuang, Jiancang
• Mori, Jim
• Maeda, Takuto
• Tsuruoka, Hiroshi
• Zhao, Xu

Titel

Automated determination of magnitude and source length of large earthquakes using backprojection and P wave amplitudes

Ist Teil von

• Geophysical research letters, 2017-06, Vol.44 (11), p.5447-5456

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2017

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Fast estimates of magnitude and source extent of large earthquakes are fundamental for disaster mitigation. However, resolving these estimates within 10–20 min after origin time remains challenging. Here we propose a robust algorithm to resolve magnitude and source length of large earthquakes using seismic data recorded by regional arrays and global stations. We estimate source length and source duration by backprojecting seismic array data. Then the source duration and the maximum amplitude of the teleseismic P wave displacement waveforms are used jointly to estimate magnitude. We apply this method to 74 shallow earthquakes that occurred within epicentral distances of 30–85° to Hi‐net (2004–2014). The estimated magnitudes are similar to moment magnitudes estimated from W‐phase inversions (U.S. Geological Survey), with standard deviations of 0.14–0.19 depending on the global station distributions. Application of this method to multiple regional seismic arrays could benefit tsunami warning systems and emergency response to large global earthquakes. Key Points Developed a new algorithm to estimate magnitudes of large earthquakes Applied this approach to Mw ≥ 7.0 earthquakes from 2004 to 2014 Propose to build an automated system for fast estimates of magnitude and source length of large earthquakes