Foundation, Concrete and Earthquake Engineering

Deep-Ocean Assessment and Reporting of Tsunami (Dart) System

Seismometers staked out around the ocean can almost instantly pinpoint a quakes location. In the next moment, complex computer programs can predict how long a triggered tsunami would take to reach coastlines, even though there have no yet a evidence of wave exists. After some minutes, tide gauges scattered along coastline may detect tsunami. But the only way to be sure whether a dangerous wave is headed toward a distant coast is to place tsunami detectors in its path and track it across the open ocean. This tsunami detectors is the DART system.

The DART system depends on bottom pressure recorders. As the crest of a tsunami wave passes by, the bottom recorder detects the increased pressure from the additional volume of overlying water.
Even from 6,000 meters depth, the sensitive instrument can detect a tsunami no higher than a single centimeter. Ship and storm waves are not detected, because their length is short and, as with currents, changes in pressure are not transmitted all the way to the ocean bottom.


When the bottom recorders detect a tsunami, acoustic chirps will transmit the measurements to a car size buoy at the ocean surface, which will than relay the information to a ground station via satellite.

More buoys would reduce the possibility that tsunami waves might sneak between them. Combined with the buoy measurements, the simulations of tsunami in computer will provide more accurate predictions to guide officials who may have only a few minutes to decide whether to sound an alarm.

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