EAGER: Geologic Evidence of Tsunamis originating from the Japan Trench's Southern Segment

EAGER：海啸源自日本海沟南段的地质证据

• 批准号: 1357722
• 负责人: Benjamin Horton
• 金额: $ 1.92万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357722&HistoricalAwards=false
• 关键词: EAGER; Geologic; Evidence; Tsunamis; originating

In the wake of the 2011 Tohoku-oki tsunami, studies modelling rupture scenarios for the Japan Trench have identified areas of uncertainty, particularly along the southern segment. The accuracy of these seismic models and the understanding of fault movement along the southern Japan Trench can be greatly improved by locating and mapping prehistoric tsunamis deposits. Records of tsunamis developed from the sedimentary deposits they leave behind, improve our understanding by expanding the age range of events available for study. This EAGER research project, carried out by scientists from the University of Pennsylvania and the Geological Survey of Japan, aims to locate geologic evidence of past tsunamis originating from the southern segment of the Japan Trench, which to date remains undocumented. The study will investigate the beach ridges and coastal ponds of Chiba region of Japan using the state-of-the-art litho-, bio-, and chronostratigraphical techniques. The research is highly exploratory in nature since, as of yet, geologic evidence of paleo-tsunamis in this region has been found.The importance of understanding the timing and magnitude of tsunamis originating from the Japan Trench was highlighted by the unexpected Mw 9.0 Tohoku-oki event in 2011. Despite generating the largest instrumental record of an earthquake, very little is known about the Japan Trench, particularly its southern segment near Tokyo. The establishment of a recurrence interval for tsunami generating earthquakes improve assessments of natural hazards to the Greater Tokyo Area, the largest metropolitan area in the world. This research will provide important new information concerning the uncertainty surrounding long-term earthquake patterns, not only for the Japan Trench, but also for other locations such as the Pacific coast of North America, Chile and Indonesia.

在2011年东北海啸之后，对日本海沟破裂情景的模拟研究已经确定了一些不确定的区域，特别是沿着南段。这些地震模型的准确性和对日本海沟南部断层运动的认识可以通过对史前海啸沉积物的定位和测绘大大提高。海啸的记录从它们留下的沉积物中发展而来，通过扩大可用于研究的事件的年龄范围，提高了我们的理解。这项EAGER研究项目由宾夕法尼亚大学和日本地质调查局的科学家开展，旨在找到日本海沟南段过去海啸的地质证据，这些证据迄今仍未得到记录。该研究将使用最先进的岩石学、生物和年代地层学技术调查日本千叶地区的海滩山脊和沿海池塘。到目前为止，在该地区已经发现了古海啸的地质证据，因此此次研究具有很强的探索性。了解源自日本海沟的海啸发生时间和震级的重要性在2011年意想不到的Mw 9.0 Tohoku-oki事件中得到了突出体现。尽管产生了最大的地震仪器记录，但人们对日本海沟知之甚少，特别是东京附近的南部地区。海啸引发地震的复发间隔的建立改善了对大东京地区自然灾害的评估，大东京地区是世界上最大的大都市区。这项研究将为长期地震模式的不确定性提供重要的新信息，不仅适用于日本海沟，也适用于其他地区，如北美太平洋沿岸、智利和印度尼西亚。