US-Turkey Workshop: Comparative studies of the North Anatolian Fault (northwest Turkey) and the San Andreas Fault (southern California); Istanbul, Turkey; August, 2006

[0624039] cromierscope：该提案是为了支持美国-土耳其研讨会：北安那托利亚断层和圣安德烈亚斯断层的比较研究，该研讨会将于2006年8月14日至16日在土耳其伊斯坦布尔举行。美国的组织者是玛丽·科米尔博士、莱昂纳多·西伯博士和克里斯托弗·索林博士，他们都来自纽约帕利塞德的哥伦比亚大学拉蒙特·多尔蒂地球观测站。外方主办人为Naci Gorur博士，伊斯坦布尔技术大学，土耳其伊斯坦布尔。加利福尼亚的圣安德烈亚斯断层和土耳其的北安那托利亚断层是两个主要的大陆转换断层，它们具有许多共同的特征。这两个断层系统都是以20-35毫米/年的速度滑动的右侧变形，危及人口众多的大都市地区：洛杉矶（1700万）和伊斯坦布尔（1300万）。工作坊结束后将进行为期两天的实地考察。目标是：开展北安那托利亚断层和圣安德烈亚斯断层的比较研究；正式确定南加州研究中心与土耳其研究机构联盟之间的合作；计划跨国项目，旨在改善南加州和土耳其西北部的地震危险评估。大约30名美国科学家与土耳其和其他研究北安那托利亚断层的国际科学家一起参加了这次研讨会，这将使创新的研究策略得以讨论。知识优势：通过鼓励对两个主要大陆转换断层进行比较研究，本次研讨会将为地震科学中的以下关键问题提供新的思路：什么过程解释了大地测量（十年）和地质（千年至数百万年）滑动率之间的差异？在一个分支断层系统中，断层是否在断层链之间交替滑动，是否沿着每条断层链保持稳定状态，或者平行断层链是否在千年的时间尺度上激活和失效？大陆转换断层在多大程度上局限于已有构造？沿着转换断层发育的深沉积盆地或高山是由什么样的机制和断层几何形状造成的？断层的几何分割能控制地震破裂的分割吗？由地壳中部地震活动性定义的断层能否可靠地投影到由地震反射数据定义的地壳上层断层或由地质填图确定的地表断层上？复杂的断层几何形状是否有利于地震成核，产生非均匀应力条件和高频地震能量？南加州社区断层和三维地震速度模型的存在将有助于比较研究，其中还包括GPS地表速度和重新定位的地震活动性，包括震源机制。研讨会的目标之一是讨论为北安那托利亚断层开发类似数字表示的策略，以便可以对两个断层系统进行定量比较。更广泛的影响：地震灾害只能预测，不能减少，其特征是地震风险评估和减少损失的关键。考虑到伊斯坦布尔和洛杉矶附近的人口密集和重要的经济活动中心，任何努力描述地震构造活动特征的项目都具有高度的社会相关性。这次研讨会将有助于启动新的跨国研究项目，这些项目将提供更好的地震预报、更好的强地面运动估计和更好的早期预警技术。所有这些都有可能大大减少地震损失。将支持若干研究生、博士后研究人员和女科学家参加研讨会。

0624039CromierScope: This proposal is to support a US-Turkey Workshop: Comparative studies of the North Anatolian Fault and the San Andreas Fault, to be held in Istanbul, Turkey, August 14-16, 2006. The U.S. organizers are Dr. Marie Cormier, Dr. Leonardo Seeber and Dr. Christopher Sorlien, all of the Columbia University Lamont Doherty Earth Observatory in Palisades, New York. The foreign organizer is Dr. Naci Gorur, Istanbul Technical University, Istanbul, Turkey. The San Andreas Fault in California and the North Anatolian Fault in Turkey are two major continental transform faults that share many characteristics. Both fault systems are right-lateral transforms that slip at rates of 20-35 mm/yr and endanger metropolitan areas with huge populations: Los Angeles (17 million) and Istanbul (13 million). The workshop will be followed by a two-day field trip. The objectives are: initiate comparative studies of the North Anatolian Fault and the San Andreas Fault; formalize collaborations between the Southern California Research Center and a consortium of research institutions in Turkey; plan multinational projects designed to improve seismic hazard assessments in southern California and northwest Turkey. The participation in this workshop of about 30 American scientists together with Turkish and other international scientists investigating the North Anatolian fault will allow innovative research strategies to be discussed.INTELLECTUAL MERITS: By encouraging comparative studies between two major continental transform faults, this workshop will shed new light on the following key issues in earthquake science: What processes account for the differences between geodetic (decadal) and geologic (millennia to millions of years) slip rates? Does fault slip alternate between strands in a branching fault system, does it remain steady state along each strand, or do parallel strands activate and deactivate on a millennium time-scale? To what extent do continental transform faults localize on pre-existing structures? What mechanisms and what fault geometries are responsible for the deep sedimentary basins or high mountains that develop along transform faults? Does the geometrical segmentation of a fault control the segmentation of earthquake ruptures? Can faults defined by seismicity at mid-crustal level be reliably projected into faults defined at upper-crustal level from seismic reflection data or at the surface from geological mapping? Does complex fault geometry favor the nucleation of earthquakes, producing heterogeneous stress conditions and high-frequency seismic energy? Comparative studies will be aided by the existence for southern California of community fault and 3D seismic velocity models that also include GPS surface velocity and relocated seismicity including focal mechanisms. One objective of the workshop will be to discuss strategies for developing a similar digital representation for the North Anatolian Fault, so that both fault systems can be quantitatively compared.BROADER IMPACTS: Seismic hazard can only be anticipated, not reduced, and its characterization is the key to earthquake risk assessment and loss reduction. Any project that strives to characterize the seismotectonic activity near Istanbul and Los Angeles is highly societally relevant, considering that both regions are so densely populated and key centers of economic activity. This workshop will help launch new multinational research projects that will provide better earthquake forecast, better estimate of strong ground motions, and better technology for early warning. All these have the potential to substantially reduce earthquake losses. Several graduate students, post-doctoral researchers, and women scientists will be supported for participating in the workshop.