1 National Earthquake Infrastructure Service, China Earthquake Administration, Beijing 100036, China 2 Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China 3 Nanjing University of Technology, Nanjing 210009, China 4 University M’Hamed Bougara of Boumerdes, Boumerdes 35000, Algeria
Spatio-temporal characteristics of aftershocks and seismogenic structure of the 2011 MW9.0 Tohoku earthquake, Japan
1 National Earthquake Infrastructure Service, China Earthquake Administration, Beijing 100036, China 2 Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China 3 Nanjing University of Technology, Nanjing 210009, China 4 University M’Hamed Bougara of Boumerdes, Boumerdes 35000, Algeria
摘要The Tohoku megathrust earthquake, which occurred on March 11, 2011 and had an epicenter that was 70 km east of Tohoku, Japan, resulted in an estimated ten′s of billions of dollars in damage and a death toll of more than 15 thousand lives, yet few studies have documented key spatio-temporal seismogenic characteristics. Specifically, the temporal decay of aftershock activity, the number of strong aftershocks (with magnitudes greater than or equal to 7.0), the magnitude of the greatest aftershock, and area of possible aftershocks. Forecasted results from this study are based on Gutenberg-Richter’s relation, Bath’s law, Omori’s law, and Well’s relation of rupture scale utilizing the magnitude and statistical parameters of earthquakes in USA and China (Landers, Northridge, Hector Mine, San Simeon and Wenchuan earthquakes). The number of strong aftershocks, the parameters of Gutenberg-Richter’s relation, and the modified form of Omori’s law are confirmed based on the aftershock sequence data from the MW9.0 Tohoku earthquake. Moreover, for a large earthquake, the seismogenic structure could be a fault, a fault system, or an intersection of several faults. The seismogenic structure of the earthquake suggests that the event occurred on a thrust fault near the Japan trench within the overriding plate that subsequently triggered three or more active faults producing large aftershocks.
Abstract:The Tohoku megathrust earthquake, which occurred on March 11, 2011 and had an epicenter that was 70 km east of Tohoku, Japan, resulted in an estimated ten′s of billions of dollars in damage and a death toll of more than 15 thousand lives, yet few studies have documented key spatio-temporal seismogenic characteristics. Specifically, the temporal decay of aftershock activity, the number of strong aftershocks (with magnitudes greater than or equal to 7.0), the magnitude of the greatest aftershock, and area of possible aftershocks. Forecasted results from this study are based on Gutenberg-Richter’s relation, Bath’s law, Omori’s law, and Well’s relation of rupture scale utilizing the magnitude and statistical parameters of earthquakes in USA and China (Landers, Northridge, Hector Mine, San Simeon and Wenchuan earthquakes). The number of strong aftershocks, the parameters of Gutenberg-Richter’s relation, and the modified form of Omori’s law are confirmed based on the aftershock sequence data from the MW9.0 Tohoku earthquake. Moreover, for a large earthquake, the seismogenic structure could be a fault, a fault system, or an intersection of several faults. The seismogenic structure of the earthquake suggests that the event occurred on a thrust fault near the Japan trench within the overriding plate that subsequently triggered three or more active faults producing large aftershocks.
基金资助:the National Natural Science Foundation of China (No. 51278474), Special Research Project of Earthquake Engineering (No. 201108003) and International Science and Technology Cooperation Program of China (No. 2011DFA21460)
通讯作者:
Jisheng Zhao
E-mail: jisheng zhao@163.com
引用本文:
Jisheng Zhao, Yanqiong Liu, Zhenghua Zhou, Farah Lazzali. Spatio-temporal characteristics of aftershocks and seismogenic structure of the 2011 MW9.0 Tohoku earthquake, Japan[J]. 《地震学报》英文版, 2012, 25(3): 219-227.
Jisheng Zhao, Yanqiong Liu, Zhenghua Zhou, Farah Lazzali. Spatio-temporal characteristics of aftershocks and seismogenic structure of the 2011 MW9.0 Tohoku earthquake, Japan. Earthquake Science, 2012, 25(3): 219-227.