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：该提案将支持2006年8月14-16日在土耳其伊斯坦布尔举行的美国-土耳其研讨会：北安纳托利亚断层和圣安德烈亚斯断层的比较研究。 美国的组织者是玛丽科蒂博士、列奥纳多西伯博士和克里斯托弗索林博士，他们都来自哥伦比亚大学拉蒙多尔蒂地球观测站，位于纽约的帕利塞兹。外方组织者是土耳其伊斯坦布尔伊斯坦布尔技术大学的Naci Gorur博士。 加州的圣安德烈亚斯断层和土耳其的北安纳托利亚断层是两条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右旋转换，以20-35毫米/年的速度滑动，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）。 讲习班之后将进行为期两天的实地考察。目标是：启动北安纳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和土耳其研究机构联盟之间的合作;计划旨在改善加州南部和土耳其西北部地震危险评估的跨国项目。 这次研讨会有大约30名美国科学家和土耳其及其他国际科学家参加，他们将对研究北安纳托利亚断层的创新性研究战略进行讨论。智力成果：通过鼓励两个主要大陆转换断层之间的比较研究，这次研讨会将对地震科学中的以下关键问题提供新的认识：什么过程解释了大地（十年）和地质（千年到数百万年）滑动率之间的差异？断层滑移是否在分支断层系统中的两股之间交替发生，它是否沿着每一股保持沿着稳定状态，或者平行股在千年时间尺度上激活和失活？大陆转换断层在多大程度上局限于先存构造？什么机制和什么样的断层几何形状是造成沿着转换断层发育的深沉积盆地或高山的原因？断层的几何分段是否控制地震破裂的分段？由中地壳水平地震活动性确定的断层能否可靠地投影到由地震反射数据确定的上地壳水平断层或由地质填图确定的地表断层？复杂的断层几何形状是否有利于地震的成核，产生不均匀的应力条件和高频地震能量？比较研究将有助于社区断层和三维地震速度模型，其中还包括GPS表面速度和重新定位的地震活动，包括震源机制的存在，为南加州。研讨会的一个目标是讨论为北安纳托利亚断层开发类似数字表示的策略，以便两个断层系统可以进行定量比较。更广泛的影响：地震危险只能预测，不能减少，其特征是地震风险评估和减少损失的关键。任何试图描述伊斯坦布尔和洛杉矶附近地震构造活动特征的项目都具有高度的社会相关性，因为这两个地区人口稠密，是经济活动的关键中心。这次研讨会将有助于启动新的多国研究项目，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。将资助一些研究生、博士后研究人员和女科学家参加讲习班。

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.