HR: 1340h
AN: OS33C-1482    [Abstracts]
TI: The Bremen Ocean Bottom Tiltmeter (OBT) for Deep Sea Short and Long Baseline Deformation Monitoring
AU: * Fabian, M
EM: marcus.fabian@uni-bremen.de
AF: University of Bremen, Department 5 Geosciences Klagenfurter Strasse, Bremen, 28359 Germany
AU: Villinger, H
EM: vill@uni-bremen.de
AF: University of Bremen, Department 5 Geosciences Klagenfurter Strasse, Bremen, 28359 Germany
AB: The Bremen Ocean Bottom Tiltmeter (OBT) is designed for autonomous high resolution deep sea tilt measurements at operation depths down to 6000m and logging duration of 1 year. Installation and retrieval of OBTs will be done by means of a remote operated vehicle. A first OBT was deployed in the Logatchev Hydrothermal Vent Field (LHF), Mid-Atlantic Ridge, 14.45°N in a depth of 3053m during research vessel 'Meteor' cruise 64.2 in May 2005. It records sea floor deformation correlated with micro seismicity, subsurface hydrothermal fluid flow and vent activity. An OBT has a biaxial Applied Geomechanics Inc. bubble tilt sensor of type 756 with resolution of 1microradiant, a range of ±10° and an integrated thermistor with resolution of 0.01K. As additional sensor, OBTs use a vertical Micro-Electro-Mechanical-System (MEMS) accelerometer of type Kistler Servo K-Beam 8330A2.5 to assess micro seismic level in the low frequency range from DC to 1Hz with a resolution of 10-5m/(s*s). With two additional OBTs to be deployed in 2006 we will establish a long baseline tilt observatory in the LHF. The instruments will be placed at a certain distance at the end points of a base line with the first OBT as the mid-point. Signal correlation will allow to study regional tilt and acceleration coherence length. We developed the OBT in the frame of project LOLEM, Logatchev Long Term Environmental Monitoring, as a part of Schwerpunktprogramm 1144, `Vom Mantel zum Ozean' founded by Deutsche Forschungsgemeinschaft which is gratefully acknowledged.
DE: 3017 Hydrothermal systems (0450, 1034, 3616, 4832, 8135, 8424)
DE: 3035 Midocean ridge processes
DE: 3050 Ocean observatories and experiments
DE: 3094 Instruments and techniques
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005