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HA05 hydroacoustic station |
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(French West Indies) of the CTBTO (Comprehensive Test-Ban Treaty Organization)
The International Monitoring System for the Comprehensive Test-Ban Treaty (IMS/CTBT) comprises, among others, 11 hydroacoustic stations providing continuous recordings, including the HA05 T-phase station in the French West Indies and the HA04 station on Crozet Island.
The HA05 station comprises two facilities:
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H05N1, located on Desirade Island just east of Guadeloupe, detects T-waves from the middle and north of the Atlantic Ocean. |
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Desirade Island. |
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H05S1, located to the south of Martinique, detects T-waves from the middle and south of the Atlantic Ocean. |
The HA05 station also monitors seismicity along the Antilles subduction zone.
Earthquakes in oceanic plates and underwater or underground explosions occurring in the vicinity of a sea or ocean generate hydroacoustic waves. These waves, propagating through the ocean, sometimes over thousands of kilometers, are recorded by underwater sensors (hydrophones) or coastal seismic stations (T-wave stations).
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Section of the HA05 seismic vault |
The station site location was chosen following a survey conducted in May 1999. The station was set up in October 1999 and certified by the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization) in March 2002.
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Seismic vault and GPS antenna mast. |
The HA05 station is equipped with 3 high-sensitivity short-period seismometers:
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One ZM 500 short-period seismometer. |
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Inside the vault. |
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Two HM 500 short-period seismometers. |
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HA05 station layout. |
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Acquisition |
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Signals from short-period seismometers are recorded at a sampling frequency of 100 points per second. Samples are dated by a GPS-synchronized clock.
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VSAT antenna and solar panels. |
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Transmission |
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Signals are transmitted continuously by VSAT (Very Small Aperture Terminal) satellite link to the French National Data Center of the DASE, then to the CTBTO (Comprehensive Test-Ban Treaty Organization) International Data Center in Vienna. |
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