Investigation of Spatial and Temporal Variation in Coda Q inRelation to Earthquake Processes

与地震过程相关的 Coda Q 时空变化研究

• 批准号: 8720856
• 负责人: Keiiti Aki
• 金额: $ 10万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720856&HistoricalAwards=false
• 关键词: Investigation; Spatial; Temporal; Variation; Coda

Recently, significant temporal variations in local earthquake coda decay rate (coda Q-1) have been observed associated with (1) the long-term migration of seismicity in China, (2) the Round Valley earthquake of 1984, (3) the North Palm Springs earthquake of 1986, (4) the Misasa earthquake of 1983 and (5) an eruption of Mt. St. Helens. Some of these variations have different patterns depending on the frequency of coda waves and the depth of earthquakes. The understanding of these phenomena is urgently needed because of their potential use as a much wanted reliable precursor for intermediate-term earthquake prediction. In order to promote the understanding, we propose to: (1) Continue work on systematic determination of spatial variation in coda Q using the USGS Central California network and the USGS/Caltech/USC southern California network. (2) Perform case studies of temporal variation in coda Q in California, such as the San Jacinto fault zone, where focal depths range from 0 to 20 km (similar to the North Palm Springs area).

最近，观测到了与(1)中国地震活动的长期迁移、(2)1984年圆谷地震、(3)1986年北棕榈泉地震、(4)1983年三萨地震和(5)山体喷发有关的局部地震尾波衰减率(Q-1)的显著时间变化。圣海伦斯。根据尾波频率和地震深度的不同，其中一些变化有不同的模式。迫切需要了解这些现象，因为它们可能被用作中期地震预报急需的可靠前兆。为了增进了解，我们建议：(1)利用USGS中央加利福尼亚网络和USGS继续系统地确定尾波Q的空间变化/加州理工/南加州大学网络。(2)以加州圣哈辛托断裂带为例，进行尾波Q随时间变化的实例研究，该断裂带的震源深度从0到20公里(类似于北棕榈泉地区)。