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

这笔赠款支持迈阿密大学和迈阿密大学之间的合作努力。RSMAS（PI：Tim狄克逊）、加州圣克鲁斯大学（主要负责人：Susan Schwartz）、联合国志愿人员组织和哥斯达黎加同事Marino Protti博士在OVSICORI获得并在哥斯达黎加的尼科亚半岛部署全球定位系统和地震设备。 该网络的观测结果将直接反馈给边缘计划（OCE-0841091/Miami-RSMAS/狄克逊和OCE-0841091/UCSC/施瓦茨）支持的研究工作。 这笔赠款将有助于扩大和升级哥斯达黎加尼科亚半岛现有的但规模较小的全球定位系统和地震仪器网络（通过IAN- 0502221供资）。 这一支助将增加另外7个全球定位系统站点，并将现有13个较老的全球定位系统站点中的5个升级到PBO标准，并允许购买和安装4个Guralp CMG 3宽带地震传感器和相关数据记录仪，以取代目前尼科西亚地震网络中的设备，目前租借。 该网络的数据将继续流入联安核查团和综合登记信息系统的可供公众查阅的数据档案。 现有的尼科亚地震大地测量网络记录了2007年5月下行板块和相关的非火山震颤的地震滑动的初步证据。 尼科亚全球定位系统和地震网络的这种扩展将更好地限制随时间变化的应变场和地震活动。 卡斯卡迪亚和日本西南部俯冲带内俯冲带动力学的类似但更高分辨率的时空观测从根本上改变了我们对俯冲带板块构造过程的理解，并对我们更好地理解地震灾害提出了挑战。 尼科亚板块边界天文台（PBO）的这一扩展将允许研究一类具有与卡斯卡迪亚和日本海沟不同性质的俯冲带，也许最重要的是，下行板的温度/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。 因此，拟议的地球物理观测站将能够对板块边界过程进行高信噪比观测。 这些仪器所收集到的数据所要解决的问题包括：1）慢滑动、非火山地震、应变积累和板间地震之间的关系。2)温度和流体在震颤和滑动产生中的作用是什么？3)快滑和慢滑震颤的发生是否在空间和/或时间上分开？这些问题的答案对了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，研究生培训，掌握最先进的地震和大地测量仪器和技术，以及提高对该区域地震灾害的认识。

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.