Developement of two ocean-bottom seismometers specialised in wide-angle seismic (MicrOBS) and seismological data acquisition (LotOBS).
Abstract
A new generation of ocean bottom seismometers (MicrOBS) has been developed in a collaboration between ORCA instrumentation/SERCEL Brest and Ifremer (French Research Institute for Exploitation of the Sea) for wide- angle seismic data acquisition. For the first time, the acquisition and release electronics have been integrated to decrease the size, weight and cost of the equipment. Downloading of data by USB cable and recharging of batteries is accomplished from the outside allowing redeployment of the equipment without opening the glass sphere. The instrument is equipped with a hydrophone and a three channel internal geophone. The instrument weight is only 19 kg and it is housed in a 13 inch glass sphere. The instrument can record for up to 14 days during a 3 week period or 22 days during a one month period depending on the choice of rechargable or normal batteries. Data from the first seismological experiments performed off Sumatra and in the Mediteranean Sea demonstrate excellent quality of data from all four channels. Ifremer is now developing an OBS specialised for seismological data acquisition (LotOBS), using the same acquisition electronics as in the MicrOBS. In order to include sufficient batteries to be able to record for 8 months (during a deplyment period of up to 12 months) the instrument is housed in a 17 inch glass sphere with a weight in air of about 50 kg. The external 4.5 Hz geophones are deployed briefly after the arrival of the instrument on the sea-floor. The first tests of the instrument will be carried out in 2008.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.S23A1100P
- Keywords:
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- 3025 Marine seismics (0935;
- 7294);
- 7294 Seismic instruments and networks (0935;
- 3025);
- 8194 Instruments and techniques