Lightning detection at Java earthquake

New software of the German tsunami early warning system enables faster localization of earths

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The earthquake with a magnitude of 7.6 off the coast of the Indonesian island of Java could be correctly localized and determined in its strength by the German tsunami early warning system GITEWS already after four minutes and 38 seconds, The location of the quake, which took place on August 9, 2007 at 12:04:58 local time, was discovered even after two minutes and eleven seconds. By comparison, the Pacific Tsunami early warning system announced its strength and herd position only after 17 minutes. This was announced by the GeoForschungsZentrum Potsdam (GFZ).

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The epicenter of the quake was about 100 kilometers east of the capital Jakarta and 110 kilometers north of Bandung. In the affected region skyscrapers staggered and many people ran in panic on the streets. However, initially nothing was known about injuries or major damages. According to experts, a tsunami danger did not exist.

Old version in use worldwide

The basis for the rapid evaluation of the quake is a new software system called "SeisComP" - Seismological Communication Processor - which was installed by the GFZ in the future tsunami warning center in Jakarta, Indonesia. It is used for the standardized collection, transmission and analysis of earthquake data in the emerging tsunami early warning system for the Indian Ocean.

The system developed by the Potsdam scientists is already being used in an earlier version by almost 100 seismological observatories and earthquake services worldwide. As part of the GITEWS project, the new software primarily improves the accelerated manual evaluation of data with the aim of early detection of possible tsunami-causing strong earthquakes. For this purpose, complex graphical user interfaces are realized, which optimally display the automatic measurement results and allow efficient interactive interventions by the staff in the warning center. display

The new version of the seismology program package replaces the previous Seiscomp system, which was implemented as an emergency measure in June 2005 after the disaster tsunami. The previous system worked exclusively automatically and did not have sufficient visual control and intervention options. The scientists were only able to localize earthquakes after more than ten minutes and relatively imprecisely. Also, the magnitude of strong earthquakes was only conditionally determined.

Work on the tsunami early warning system is progressing

This work is part of building a tsunami early warning system in the Indian Ocean. Professor Reinhard Hüttl, CEO of the GFZ Potsdam, who is in charge of setting up the GITEWS, says: "With German help, Indonesia has thus taken a major step closer to its self-defined goal, the location and strength of earthquakes in less than five Minutes to determine. The new system is now running in real time and has already successfully localized the first quake events. After completion in late 2008, the state-of-the-art tsunami warning seismological network will be in operation here. "

Construction of the GITEWS seismic survey network is progressing: nine of the planned stations have already been set up: Nias, Sumatra (2), Krakatau, Java (2), Kalimantan, Flores and the Moluccas. Another five stations are in preparation. The speed of further expansion depends largely on "non-scientific" factors such as land purchase and construction of the seismic bunker and the flight ban for the Indonesian airlines.

quality not quantity

There are now over 60 other seismic stations in Indonesia (45 Indonesian, 15 Japanese) that are also recorded and processed in the Seiscomp system, but for the most part their data quality is very poor and does not reach the quality of the GITEWS stations.

In addition, there are some Chinese stations without data transmission as well as some older French analogue stations, which can not be used because of their poor data quality.

(idw - GeoForschungsZentrum Potsdam, 10.08.2007 - DLO)