Geodetic observations at the early stage of subduction zone seismic cycle: towards complete seismic cycle coverage

俯冲带地震周期早期大地测量观测：走向完整的地震周期覆盖

• 批准号: 1345100
• 负责人: Timothy Dixon
• 金额: $ 26万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1345100&HistoricalAwards=false
• 关键词: Geodetic; observations; early; stage; subduction

Subduction zones such as those along the Pacific ?Ring of Fire? produce Earth?s largest and most destructive earthquakes, and most tsunamis. The giant earthquakes and tsunamis of 2004 (Sumatra) and 2011 (Japan) were wake up calls that our ability to estimate future earthquake magnitude remains weak. Measurement of strain accumulation in the vicinity of subduction zones, as is now possible with high precision GPS units, has the potential to forecast the location and size of future earthquakes. The coastal Nicoya Peninsula of Costa Rica lies close to the trench (70 km), allowing observations directly over the seismogenic zone. Here I propose to upgrade and operate a continuous high precision GPS network in the Nicoya Peninsula, and use the resulting data to investigate a number of questions related to seismic and tsunami processes in the subduction zone environment. In principle these kind of measurements could provide predictive capability in terms of location and size of future earthquakes and perhaps tsunamis (timing would still presumably be unknown). Northern Costa Rica is characterized by fast (~8 cm/yr) subduction and a short (50?60 year) earthquake cycle, producing frequent large (M7.5) earthquakes including events in 1853, 1900, 1950 (M 7.7) and most recently September 5, 2012 (M 7.6). Previous NSF-funded studies in this region have defined the regional tectonics and quantified a number of key seismogenic parameters at the late stage of the seismic cycle, including the pattern of interseismic strain accumulation and microseismicity, and the nature and timing of slow slip events (SSE). The 2012 earthquake gives us a chance to investigate these processes at the beginning of a seismic cycle, providing the scientific community an incredible opportunity to characterize a complete seismic cycle. All data generated by the Nicoya C-GPS network are made publicly available through UNAVCO, and analyzed products (e.g, coseismic and slow slip offsets) are available on my website (http://labs.cas.usf.edu/geodesy/) to assist researchers who are unfamiliar with the details of GPS processing use the data for earthquake research.

俯冲带，例如太平洋火环的俯冲区？产生地球最大，最具破坏性的地震，以及大多数海啸。 2004年（苏门答腊）和2011年（日本）的巨型地震和海啸是唤醒呼吁，即我们估计未来地震幅度的能力仍然很弱。 俯冲带附近应变积累的测量，如今可以使用高精度的GPS单位，可以预测未来地震的位置和大小。 哥斯达黎加的沿海尼古亚半岛位于沟渠附近（70公里），可以直接在地震区域进行观察。 在这里，我建议在尼科亚半岛升级和操作一个连续的高精度GPS网络，并使用结果数据来研究与俯冲区环境中与地震和海啸过程有关的许多问题。 原则上，这些测量值可以从未来地震的位置和大小以及可能的海啸（可能仍然是未知的）方面提供预测能力。 哥斯达黎加北部的特征是快速（约8厘米/年）的俯冲和短期（50？60年）地震周期，在1853年，1900年，1950年（M 7.7）（M 7.7）和最近9月5日（2012年9月5日）（M 7.6）（M 7.6）（M 7.6）中频繁发生大型（M7.5）地震（M 7.7）。 在该地区，NSF资助的先前由NSF资助的研究定义了区域构造，并在地震循环的后期量化了许多关键的地震源性参数，包括跨界应变的积累和微震动性的模式，以及慢滑动事件的性质和时间（SSE）。 2012年的地震使我们有机会在地震周期开始调查这些过程，从而为科学界提供了一个令人难以置信的机会来表征完整的地震周期。 Nicoya C-GPS网络生成的所有数据均通过UNAVCO公开提供，分析的产品（例如，Coseissic和Slow Slip Offsets）可在我的网站（http://labs.cas.usf.edu/geodesy/）上获得，以帮助对GPS Grocessing for EarteAke for EarteAke for EarteAke的详细信息进行研究。