
Every sea floor earth quake or sea floor volcanic eruption does not trigger a Tsunami. Considering the damage caused by the Tsunamis in the past, definitely Tsunami Early Warning Systems are necessary. Same time we can not afford to have false tsunami warnings as they are costly to the people and to the government initiating preventive actions. There are occasions where tsunami warnings were false. Though false warning is better than no warning, false tsunami warnings are to be minimized. A reliable Tsunami Early Warning System is necessary.
GITEWS is a project under development by the German Government to ensure a reliable German Indonesian Tsunami Early Warning System. It is accomplished by a consortium of nine institutions:
GeoForschungsZentrum Potsdam (GFZ), Alfred Wegener Institute for Polar and Marine Research (AWI), Federal Institute for Geosciences and Natural Resources (BGR), German Aerospace Center (DLR), GKSS Forschungszentrum Geesthacht, Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), Konsortium Deutsche Meeresforschung (KDM), Leibniz Institute of Marine Sciences (IFM-GEOMAR), United Nations University Institute for Environment and Human Security (UNU-EHS).
For a reliable tsunami early warning, sea level recordings must take place off the coast, in the deep ocean. At water depths of thousands of meters, a tsunami wave travels at several hundred km/hr, but is only some tens of centimetres high, and approximately one hundred kilometres long. Only when a tsunami wave reaches the coast or shallower waters, the wave develops into a massive wall of water several meters high. Detection of very slight sea level rise in the deep ocean reliably and precisely requires the use of bottom pressure sensors (BPS). These BPSs are installed on the seafloor, where they measure even any small sea level changes in the water column above. In this process, the weight of any additional water leads to minute pressure increases at the seafloor which are, nevertheless, reliably recorded by the PACT (Pressure-based Acoustically Coupled Tsunami detector ) bottom units, precision instruments built by Optimare in Bremerhaven.
Continue Reading…