Materials of the International Conference
50th Anniversary of the International Geophysical Year
and Electronic Geophysical Year

16-19 September 2007 • Suzdal, Russia

Modern geophysical systems and independent bottom stations for long-term seismological monitoring

D. G. Levchenko1 and A. A. Paramonov2

1Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia

2Experimental and Designing Bureau of Oceanological Technology, Russian Academy of Sciences, Moscow, Russia

Abstract

The lack of marine stationary seismological network does not allow us to assess adequately geotectonic processes going on in the Earth interior both as a whole and in their variety. Short-term prediction of strong submarine earthquakes and tsunami warning still remain urgent problems. In this context it appears necessary that a single seismolological network should be set up on land and in the sea. Recording seismic signals on the water area floor significantly differs from recording on the surface. Major differences are the influence of the water layer and flooded layer of sediments, the processes of seismic recorder body interactions with the soft bottom, and noise excited by bottom currents. There are technical problems as well, specifically rapid delivery of information to surface centers. The use of underwater cables could be a solution but the cost of underwater long cable lines of communication is very high. The achievements of modern science and technology in marine instrument engineering allow constructing and operating modern independent marine geophysical systems and independent bottom stations (IBSS) to conduct prolonged seismological monitoring. High mobility of independent bottom stations enables us to set up a network of stations rapidly and in any area of the oceans of the world with high accuracy of coordinates and time synchronization. The cost of IBSS is many times less than the cost of cable stationary stations. Long-term buoys constructions are known which may allow us to establish stable communication with the independent bottom station through radio and satellite channels. At present, the development of a stationary marine seismological network with meteorological parameters approximately similar to the surface network can be carried out on the basis of long-term independent bottom stations at acceptable costs. In the paper, the results of the analysis of seismic signals registration on the water area floor are given, problems of technology of long-term seismological observations are considered, examples of modern marine geophysical systems and bottom independent stations are given as well as examples of records obtained with the use of those systems. The paper sums up work conducted in marine seismology in Shirshov Institute of Oceanology RAS and Experimental and Designing Bureau of Oceanological Technology RAS.

Citation: D. G. Levchenko and A. A. Paramonov (2007), Modern geophysical systems and independent bottom stations for long-term seismological monitoring, in: Materials of the International Conference '50th Anniversary of the International Geophysical Year and Electronic Geophysical Year', GC RAS, Moscow, doi:10.2205/2007-IGY50conf.

© 2007 Geophysical Center RAS and authors


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