Collection, Documentation and Dissemination of Strong Motion Data From Recent Large Earthquakes in Japan

9527929萨默维尔这个项目的目标是收集和提供最近日本大地震的数字强震记录；记录解释和使用数据所需的震源、路径和场地参数；将它们与美国使用的衰减关系进行比较；并就它们与美国地面运动的相关性提供评论。其目的是为地震工程研究界提供基本数据。在1993年1月15日至1995年1月17日的两年时间里，日本发生了5次大地震，并被广泛记录下来。这些地震中最小的一次是1995年1月17日发生的6.9级神户地震，因为它发生在人口稠密的城市地区，所以破坏性最大。其他四次地震，震级在7.5到8.1级之间，都发生在俯冲带，都比我们有记录的美国任何一次强震都要大。这些强震数据很难获得，美国的大多数调查人员也不知道如何获取它们。此外，这些数据不能直接用于经验地震动模型的开发，因为与美国相比，日本使用不同的震级(JMA震级而不是矩震级)；在日本使用震中距离而不是到断层的最近距离。这些条件导致这些潜在有价值的强震数据得不到充分利用。该项目涉及以下内容：1.收集数字强震时间历史，以及解释和使用时间历史所需的多种信息。这些参数包括震源参数，如地震矩、震源机制和构造类别；描述距离记录地点最近距离的路径参数；以及记录地点现有的岩土工程数据。2.利用这些数据，将日本的地面运动与美国的相应经验衰减关系进行了比较。3.在这种比较的基础上，编写一份关于这些记录的评论，说明它们是否适合美国的特定震源区。数字时间历史、参数信息、比较和评论将在互联网上存档，并提供给科罗拉多州博尔德市的国家地球物理数据中心。拟议的工作将执行1993年国际强震数据讲习班关于传播日本最近地震的强震数据的所有主要建议。***

9527929 Somerville The objectives of this project are to gather and provide access to digital strong motion recordings from recent large Japanese earthquakes; to document the source, path and site parameters required for the interpretation and use of the data; to compare them with attenuation relations used in the United States; and provide commentary on their relevance to ground motions in the United States. The aim is to provide basic data for use by the earthquake engineering research community. In the two year period between January 15, 1993 and January 17, 1995, five major earthquakes occurred and were widely recorded in Japan. The smallest of these earthquakes, the magnitude 6.9 Kobe earthquake of January 17, 1995, was the most damaging because of its occurrence in a dense urban region. The four other earthquakes, with magnitudes in the range of 7.5 to 8. 1, occurred in subduction zones, and were all larger than any earthquake in the United States for which we have strong motion recordings. These strong motion data are difficult to acquire, and most investigators in the United States do not know how to acquire them. Further, the data cannot be directly used in the development of empirical ground motion models because different magnitude scales are used in Japan as compared to the USA (JMA magnitude instead of moment magnitude); and epicentral distance is used in Japan instead of the closest distance to the fault. These conditions result in the underutilization of these potentially valuable strong motion data. The project involves the following: 1. Gather digital strong motion time histories together with the many categories of information that are required for the interpretation and use of the time histories. These include source parameters such as seismic moment, focal mechanism and tectonic category; path parameters describing the closest distance to the recording site; and available geotechnical data from the recording sites. 2. Using these data, c ompare the Japanese ground motions with corresponding empirical attenuation relations used in the United States. 3. Based on this comparison, prepare a commentary on the records describing their appropriateness for particular seismic source regions in the United States. The digital time histories, parameter information, comparisons, and commentary will be archived on the Internet and provided to the National Geophysical Data Center in Boulder, Colorado. The proposed work will implement all of the major recommendations of the 1993 International Workshop on Strong Motion Data concerning the dissemination of strong motion data from recent earthquakes in Japan. ***