Rapid Response to Diking/Eruptive Event at Axial Seamount, February, 1998

摘要本项目是对胡安德富卡海岭轴向海山地震事件的快速响应。从1998年1月28日开始，使用NOAA/PREL开发的t相位监测系统探测到地震事件，该系统访问了美国海军的SOSUS阵列。在事件发生的头几天就检测到6000多次地震，使其成为该地区迄今为止观测到的最强烈的地震事件。这次地震活动的特征与在同轴段和北戈尔达岭观测到的地震活动非常相似，这两个事件后来被证实是爆发事件。建议是在R/V Wecoma上进行一次快速反应巡航。目标是：(1)检测和表征与地震事件相关的事件羽流和其他喷口，(2)部署中立浮标和漂流浮标（RAFOS浮标）以及相关声源阵列，以跟踪事件羽流，(3)确定是否存在地下细菌爆发，(4)推进地球化学和微生物浓度的时间序列测量，以及在巨型羽流和事件引发的羽流中活动，(5)部署海底水听器。

Cowen, James P. OCE-9810026 Abstract This project is a rapid response to an seismic event on Axial seamount on the Juan de Fuca Ridge. Starting January 28, 1998, a seismic event was detected using the T-phase monitoring system developed by NOAA/PREL to access the US Navy's SOSUS arrays. Over 6000 earthquakes were detected in the first days of the event, making this the most intense seismic event yet observed in this area. The character of this seismicity is very similar to that observed at CoAxial segment and the Northern Gorda Ridge, both episodes that were later confirmed to be eruptive events. The proposal is to mount a rapid response cruise on the R/V Wecoma. The Objectives are to: (1) detect and characterize events plume(s) and other venting associated with the seismic event, (2) to deploy neutrally buoy and drifter buoys (RAFOS floats) and associated sound source array for tracking an event plume, (3) establish whether there has been a subsurface bacterial bloom, (4) advance time-series measurements of geochemical and microbial concentrations and activities in megaplume and event-initiated plumes, and (5) deploy ocean bottom hydrophones.