Collaborative Research: Acquisition of GPS and seismic equipment for Phase 2 of a Plate Boundary Observatory, Nicoya Peninsula, Costa Rica

合作研究：为哥斯达黎加尼科亚半岛板块边界观测站第二阶段采购 GPS 和地震设备

• 批准号: 1140261
• 负责人: Timothy Dixon
• 金额: $ 3.09万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1140261&HistoricalAwards=false
• 关键词: Collaborative; Research; Acquisition; GPS; seismic

This grant supports a collaborative effort between the University of Miami ? RSMAS (PI: Tim Dixon), the University of California Santa Cruz (PI: Susan Schwartz), UNAVCO and Costa Rican colleague Dr. Marino Protti at OVSICORI to acquire and deploy GPS and seismic equipment on the Nicoya Peninsula, Costa Rica. Observation from this network will directly feed into research efforts supported by the Margins Program (OCE-0841091/Miami-RSMAS/Dixon and OCE-0841091/UCSC/Schwartz). This grant will facilitate an augmentation and upgrade to a current but smaller network of GPS and seismic instrumentation on the Nicoya Peninsula, Costa Rica (funded through EAR- 0502221). The end result will be extended and better constrained geophysical observations in time and space beyond that now being acquired.This support will add an additional seven GPS sites and upgrade five of the older existing thirteen GPS sites to PBO standards as well as allow for the purchase and installation of four Guralp CMG3 broadband seismic sensors and associated data loggers to replace equipment in the current Nicoya seismic network that are currently on loan. Data from the network will continue to flow to the UNAVCO and IRIS publicly accessible data archives. The existing Nicoya seismogeodetic network has recorded initial evidence of aseismic slip of the downgoing slab and associated nonvolcanic tremor in May 2007. This expansion of the Nicoya GPS and seismic network will better constrain the time varying strain field and seismic activity. Similar albeit higher resolution space-time observations of subduction zone dynamics within the Cascadia and SW Japan subduction zones have radically changed and challenged our understanding of plate tectonic processes at subduction zones with implications for better understanding seismic hazards. This expansion of the Nicoya Plate Boundary Observatory (PBO) will allow for study of a class of subduction zone with different properties from those of the Cascadia and Japan trenches, perhaps most importantly, temperature/age of the downgoing slab. The Nicoya Peninsula is unique in that it is perched almost directly over the locked part of the plate boundary. As a result, the proposed geophysical observatory will enable high signal/noise (S/N) ratio observations of plate boundary processes. Questions to be addressed by the data collected by these instruments include: 1) What is the relationship between slow slip, nonvolcanic tremor, strain accumulation and interplate earthquakes. 2) What is the role of temperature and fluids in tremor and slip generation? 3) Is the occurrence of fast and slow slip tremor spatially and/or temporally separated? The answers to these questions have important implications for understanding the seismic process at subduction zones.Broader impacts will include international cooperation and technology transfer, graduate student training with state-of-the-art seismic and geodetic instrumentation and techniques, and improved understanding of earthquake hazards in the region.

这项拨款支持迈阿密大学和RSMAS (PI: Tim Dixon)，加州大学圣克鲁斯分校（PI: Susan Schwartz）， UNAVCO和哥斯达黎加同事OVSICORI的Marino Protti博士在哥斯达黎加Nicoya半岛获取并部署GPS和地震设备。该网络的观测结果将直接提供给边际计划（OCE-0841091/Miami-RSMAS/Dixon和OCE-0841091/UCSC/Schwartz）支持的研究工作。这笔拨款将促进对哥斯达黎加Nicoya半岛现有但较小的GPS和地震仪器网络的增强和升级（通过EAR- 0502221资助）。最终结果将是在时间和空间上比目前所获得的更广泛和更有约束的地球物理观测。这项支持将增加7个GPS站点，并将现有的13个旧GPS站点中的5个升级到PBO标准，并允许购买和安装4个Guralp CMG3宽带地震传感器和相关数据记录器，以取代目前Nicoya地震网络中目前借来的设备。该网络的数据将继续流入联阿援助团和综合信息系统的公开数据档案。现有的尼科亚地震测地网记录了2007年5月下行板块的地震滑动和相关的非火山震动的初步证据。Nicoya GPS和地震台网的扩展将更好地约束时变应变场和地震活动。在卡斯卡迪亚和日本西南部的俯冲带中，类似的高分辨率俯冲带动力学时空观测从本质上改变并挑战了我们对俯冲带板块构造过程的理解，这对更好地理解地震危险具有重要意义。尼科亚板块边界观测站（PBO）的扩展将允许研究一类与卡斯卡迪亚海沟和日本海沟性质不同的俯冲带，也许最重要的是，研究下降板块的温度/年龄。尼科亚半岛的独特之处在于它几乎直接位于板块边界的锁定部分之上。因此，拟议的地球物理观测站将实现对板块边界过程的高信噪比观测。这些仪器收集的数据需要解决的问题包括：1)慢滑、非火山震动、应变积累与板块间地震之间的关系是什么？2)温度和流体在震颤和滑动产生中的作用是什么？3)快滑和慢滑的发生在空间和/或时间上是分开的吗？这些问题的答案对于理解俯冲带的地震过程具有重要意义。更广泛的影响将包括国际合作和技术转让，用最先进的地震和大地测量仪器和技术培训研究生，以及提高对该地区地震灾害的了解。