Collaborative Research: A Real-Time Nearshore Seafloor Seismic Station

申请资金用于开发和测试一个系泊系统，用于收集来自沿海海洋的实时、高带宽地震信息，这些信息在活动边缘呈现出与构造和地震力学相关的各种基本科学问题。该地区还具有地震和火山灾害的特点，可以利用海上监测站更好地进行监测。拟议中的实时海上地震站（RTOSS）由三个部分组成：具有实时输出的埋地地震仪，地震仪与水面浮标的硬接线连接，以及从水面浮标到海岸站的太阳能射频遥测链路。LDEO将开发地震仪器和传感器的部署/埋藏机制，美国地质勘探局将实施数据存档和基于网络的数据传播系统。WHOI将开发系泊系统、射频遥测系统，并领导系泊作业现场的工作。系泊设计的关键要素是一根30米长的软管，它将锚连接到系泊的垂直部分。在正常的系泊张力下，这种软管能够拉伸到其未拉伸长度的2.4倍，使系泊系统能够在保持系泊电缆张力的同时对波浪、潮汐和水流做出反应。软管内部的电导体呈螺旋状，将信号传输到E/M系泊电缆，然后传输到水面浮标。地震检波器部署在离系泊锚一定距离的地方，通过铠装电缆与之相连，将被安装在沉积物中，以保护其免受损坏，并提供更好的与地面的耦合。地震仪的全速率数据将通过系泊电缆和软管发送到地面，并使用射频调制解调器遥测到岸上。该系统还将收集海底压力和压力梯度数据，用于抑制海浪的噪音。传感器和射频链路的电力由水面浮标上的太阳能电池板产生。系统开发和原型制造计划在第一年进行。在第二年，该系统将在伍兹霍尔附近的一个地点进行长期测试。该系泊系统将在第三学年部署，并在位于格林纳达近海的海底火山Kick'em Jenny附近操作，该火山具有高水平的地震活动。

Proposal Title: Collaborative Research: A Real-Time Nearshore Seafloor Seismic Station Funds are requested to develop and test a mooring system to collect real time, high bandwidth seismic information from the coastal ocean, which at active margins presents a variety of fundamental scientific questions related to tectonics and earthquake mechanics. This region is also characterized by seismic and volcanic hazards that can be better monitored using offshore stations. The proposed Real Time Offshore Seismic Station (RTOSS) consists of three elements: a buried seismometer with real-time output, a hardwired compliant connection from the seismometer to a surface buoy, and a solar powered RF telemetry link from the surface buoy to a shore station. LDEO will develop the seismic instrumentation and the deployment/burial mechanism for the sensor and the USGS will implement the data archiving and web-based data dissemination system. WHOI will develop the mooring system, RF telemetry system and lead the mooring operations field efforts. The key element in the mooring design is a 30-meter long hose that connects the anchor to the vertical part of the mooring. This hose is capable of stretching to 2.4 times its unstretched length under normal mooring tensions giving the mooring the capability to respond to waves, tides and currents while maintaining tension in the mooring cable. Electrical conductors are spiraled in the hose interior to transfer signals to the E/M mooring cable and then to the surface buoy. The seismometer, which is deployed some distance from the mooring anchor and connected to it by armored cable, will be installed into the sediments to shield it from damage and provide for better coupling to the ground. Full rate data from the seismometer will be sent to the surface via the mooring cables and hose and telemetered to shore using an RF modem. The system will also collect seafloor pressure and pressure gradient data that will be used to suppress noise from ocean waves. Power for the sensor and RF link are generated by solar panels on the surface buoy. System development and prototype fabrication is scheduled for Year 1. During Year 2, a long-term test of the system will be conducted at a site near Woods Hole. The mooring will be deployed in Year 3, and operated near Kick'em Jenny, an underwater volcano with high levels of seismic activity located offshore of Grenada.