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

在2011年东北海啸之后，模拟日本海沟破裂情景的研究发现了不确定的领域，特别是沿南段。通过定位和绘制史前海啸沉积物的位置和地图，这些地震模型的精度和对日本南部海沟断层运动的理解可以大大提高。从海啸留下的沉积沉积物发展而来的海啸记录，通过扩大可供研究的事件的年龄范围，提高了我们的理解。这项急切的研究项目由宾夕法尼亚大学和日本地质调查局的科学家进行，目的是找到过去起源于日本海沟南段的海啸的地质证据，该海沟迄今仍未被记录在案。这项研究将使用最先进的岩石学、生物地层学和年代地层学技术对日本千叶地区的海滩脊和沿海池塘进行调查。这项研究具有很高的探索性，因为到目前为止，已经在该地区发现了古海啸的地质证据。2011年出人意料的Mw 9.0东北地震突显了了解源自日本海沟的海啸的时间和强度的重要性。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段。确定引发海啸的地震的复发间隔，改善了对世界上最大的大都市区--大东京地区的自然灾害的评估。这项研究将为围绕长期地震模式的不确定性提供重要的新信息，不仅对日本海沟，而且对北美太平洋沿岸、智利和印度尼西亚等其他地区也是如此。

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.