MW9 Tohoku earthquake in 2011 in Japan: precursors uncovered by natural time analysis |
| |
Authors: | Panayiotis A. Varotsos Nicholas V. Sarlis Efthimios S. Skordas Mary S. Lazaridou-Varotsos |
| |
Affiliation: | 1.Department of Physics, Section of Solid State Physics and Solid Earth Physics Institute, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos 157 84, Athens, Greece2.Department of Physics, Solid Earth Physics Institute, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos 157 84, Athens, Greece |
| |
Abstract: | This paper reviews the precursory phenomena of the 2011 M W9 Tohoku earthquake in Japan that emerge solely when we analyze the seismicity data in a new time domain termed natural time. If we do not consider this analysis, important precursory changes cannot be identified and hence are missed. Natural time analysis has the privilege that enables the introduction of an order parameter of seismicity. In this frame, we find that the fluctuations of this parameter exhibit an unprecedented characteristic change, i.e., an evident minimum, approximately two months before Tohoku earthquake, which strikingly is almost simultaneous with unique anomalous geomagnetic field variations recorded mainly on the z component. This is consistent with our finding that such a characteristic change in seismicity appears when a seismic electric signal (SES) activity of the VAN method (from the initials of Varotsos, Alexopoulos, Nomicos) initiates, and provides a direct confirmation of the physical interconnection between SES and seismicity. |
| |
Keywords: | Seismic electric signals VAN method Natural time analysis Earthquake prediction |
本文献已被 SpringerLink 等数据库收录! |
| 点击此处可从《地震科学(英文版)》浏览原始摘要信息 |
|
点击此处可从《地震科学(英文版)》下载免费的PDF全文 |
|