名家论坛
2017-21
应304am永利集团官网金振民院士和王墩教授邀请,国际知名地震学家Jim Mori教授访问我校并做学术报告。
报告时间:2017年6月16日(周五)上午10:30-11:40
报告地点:八角楼
报告题目:Frictional and Radiated Energy for the Shallow Fault of the 2011 Tohoku-oki Earthquake
报告人简介:
Jim Mori教授1984年毕业于美国哥伦比亚大学,获得地球物理学博士学位。先后在巴布亚新几内亚、哥伦比亚大学、USGS、日本京都大学等地工作。Jim Mori教授现为美国AGU Fellow、日本京都大学防灾研究所地震灾害部门负责人、美国地震学会董事会成员、日本京都大学教授。曾任IOPD科学规划委员会主席、ICPD科学规划委员会主席、美国地震学会会长、日本地震学会副会长、日本东北M9大地震重大钻探计划的发起人与首席科学家。他兴趣广泛,在震源物理、实时地震学、地球动力学及火山活动均有广泛研究,在国际顶级学术刊物发表学术论文百余篇。
报告内容简介:
Recent results from the Japan Trench Fast Drilling Project (JFAST) estimated the level of dynamic friction on the shallow portion of the fault that had the very large slip during the 2011 Tohoku-oki earthquake. During this Integrated Ocean Drilling Program (IODP) expedition, borehole samples were obtained from the plate boundary fault zone at 820 meters below the sea floor. Also, temperature monitoring in the borehole across the fault zone measured the level of frictional heat generated at the time of the earthquakes. From both high-speed laboratory experiments on the fault zone material (Ujiie et al., 2013) and the temperature observations across the fault zone, the shear stress during the earthquake rupture was estimated to be about 0.6 MPa. This shear stress corresponds to a coefficient of friction of about 0.08 to 0.1.
Comparing these results with estimates of the radiated energy, which are derived from teleseismic body waves, shows that the radiated energy is larger than the frictional heat for the shallow portion of the fault.
However, for the deeper portions of the fault, the frictional heat is larger. The shallow and deep portions of the megathrust have different proportions for the energy balance and, thus, different styles of faulting.
304am永利集团官网
科学技术发展院
GPMR国家重点实验室
2017年6月