8141

Sonardyne UK (Head Office) T. +44 (0) 1252 872288 F. +44 (0) 1252 876100 E. sales@sonardyne.com www.sonardyne.com Datasheet Tsunami Detection System Description The Tsunami Detection System can be deployed on the seabed in the deep ocean from where it will monitor the pressure of the water above it. A tsunami wave in deep water creates a small but measurable change in pressure that will be maintained for as long as twenty minutes. By monitoring any such changes, the subsea detector will trigger an alarm that sends an acoustic warning message to a buoymounted transceiver on the surface. The transceiver, in turn, relays the message via a satellite data link to a control centre. Sonardyne’s tsunami system is based on the company’s successful Compatt 5 seabed acoustic transponder. It uses the latest Wideband™ digital acoustic technology to provide robust through water communications in difficult acoustic conditions. The Compatt 5 may be deployed in water up to 7,000 metres and it is fitted with a sensor that continuously monitors water pressure, saving data every fifteen minutes. Because a reliable early warning of a tsunami can only be obtained close to the sea floor, the Compatt provides the essential means of sending these readings up to the surface. Every hour the Compatt converts the pressure readings into signals which it transmits acoustically to the buoy on the surface. The satellite communications transceiver on the buoy then automatically forwards the pressure readings to the tsunami monitoring agency ashore. The system can also receive data from the central control so that revised monitoring parameters can be downloaded to the Compatt if required. The Compatt is programmed to anticipate continual changes in the pressure of the water as these can be caused by influences such as tides, weather conditions and temperature. Because such changes can be predicted, a variation of as little as 3cm from the expected pattern will switch the device into Tsunami Alert Mode. This will cause the Compatt to immediately transmit any data that has been saved during the past hour to the surface. It will then take pressure readings every fifteen seconds which it will immediately send up to the buoy for transmission by satellite to the monitoring station. This means that the first warning of a tsunami, caused by a small variation in water pressure on the seabed thousands of miles from shore, can be in the office of the monitoring organisation within minutes. Sonardyne UK (Head Office) T. +44 (0) 1252 872288 F. +44 (0) 1252 876100 E. sales@sonardyne.com www.sonardyne.com Specifications Tsunami Detection System Features Frequency Band Transducer Beamshape Transmit Source Level (dB re 1 µPa @1m) Receive Sensitivity (dB re 1µPa) Telemetry Robust Wideband™ Sonardyne Messaging Service data buffer Command/Control Error Detection & Correction Communications Interface Dimensions (LxDia) Weight in Air / Water External power requirement Type 8141 Buoy Mounted Transceiver LMF (14-19kHz) Directional 196 dB 95-130dB 1,500 baud (>600 baud user payload) bi-directional 128 Bytes Accessed through communications interface Advanced protocols to minimise data loss and re-sends. RS232/485 (9,600–115,200 baud) with hardware handshake 585mm x 183mm 9.75kg / 5.26kg 24-50 Volts dc Features Depth Rating Frequency Band Transducer Beamshape Transmit Source Level (dB re 1µPa @ 1m) Receive Sensitivity (dB re1µPa) Telemetry Robust Wideband™ Battery Life (Monitoring) Safe Working Release Load (4:1) Dimensions (LxDia) Weight In Air / Water Pressure sensor Type 8106 Compatt 5 Seabed Tsunameter 5,000 metres ( 7,000m option) LMF (14–19kHz) Directional 187-197dB (3 Levels) 85-120dB (4 Levels) 1,500 baud (>600 baud user payload) bi-directional 683 days 250kg 1103mm x 135mm 28.2kg / 14.2kg 7,000 metres (4,000m option) Specifications subject to change without notice - 02/2007