HR: 1340h
AN: OS43B-0568    [Abstracts]
TI: Deployment of a Deep-Water, Acoustically-Linked, Moored Buoy Observatory on the Nootka Fault, off Vancouver Island
AU: * Frye, D
EM: dfrye@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Freitag, L
EM: lfreitag@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Collins, J
EM: jcollins@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Grund, M
EM: mgrund@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Ware, J
EM: jware@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Detrick, R
EM: rdetrick@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 United States
AU: Johnson, R
EM: johnson@ocean.washington.edu
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AU: Lilley, M
EM: lilley@ocean.washington.edu
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AU: Wilcock, W
EM: wilcock@ocean.washington.edu
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AU: LaBonte, A
AF: Scripps Institution of Oceanography, Univ. of Calif, San Diego, La Jolla, CA 92093 United States
AU: Brown, K
EM: kmbrown@ucsd.edu
AF: Scripps Institution of Oceanography, Univ. of Calif, San Diego, La Jolla, CA 92093 United States
AU: Delaney, J
EM: jdelaney@u.washington.edu
AF: School of Oceanography, University of Washington, Seattle, WA 98195 United States
AB: We have developed an acoustically-linked moored buoy system that uses high-speed acoustic modems for two-way communication between instruments on the seafloor, or in the water column, and a surface buoy. An Iridium satellite link on the buoy telemeters data to shore several times a day and can be used in conjunction with the two-way acoustic link to send commands to instruments at the observatory. This system is ideally suited for a variety of applications where data telemetry requirements are relatively modest, but real-time or near real-time data are required. A conventional discus buoy (2.7m diameter) is equipped with dual Iridium transceivers, two acoustic modems, a Linux-based system controller, and a solar power system with a three-month alkaline battery backup. Up to 15 remote nodes on the mooring or on the seafloor can be polled several times a day and the data passed back to shore via the Iridium satellite link. Total demonstrated data throughput has been ~1 Mbyte/day and can be much higher. An initial 2 month test deployment in Nov. 2003 off the U.S. east coast verified the operation of the acoustic and Iridium data links, as well as the control, power and mooring systems. Acoustic data rates of up to 5300 b/s have been achieved in 2700m of water at slant ranges of just under 3 km using modest transmit power ($<$10W). The Iridium connection has been used to remotely reconfigure various aspects of the data collection system as well as transfer large quantities of data. In May 2004 this system was deployed for one year at a seep site off Vancouver Island where the Nootka fault crosses the toe of the accretionary prism in order to monitor fluid expulsion along the fault, and to examine the links between seismic deformation and episodic flow. The Nootka observatory is equipped with a suite of meteorological sensors on the buoy, an in-line current meter on the mooring, an Ocean Bottom Seismometer, and two additional seafloor nodes, one of which is equipped with sensors for monitoring the seep site, including temperature, fluid resistivity, heat flow, and an optical flow meter. The data from these sensors are collected on shore automatically and displayed on a web page in near real time (http://fathom2.whoi.edu/). Initial results from this prototype observatory will be shown based on data telemetered to shore in near-real time.
UR: http://fathom2.whoi.edu
DE: 7230 Seismicity and seismotectonics
DE: 3015 Heat flow (benthic) and hydrothermal processes
DE: 3094 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting