HR: 1330h
AN: S52D-0166    [PDF]
TI: Earthquake Waveforms Recorded By Ocean-bottom Seismometers In The South Tyrrhenian Sea
AU: * Thorwart, M
EM: thorwart@dkrz.de
AF: Institute of Geophysics University of Hamburg, Bundesstrasse 55, Hamburg, 20146 Germany
AU: Dahm, T
EM: dahm@dkrz.de
AF: Institute of Geophysics University of Hamburg, Bundesstrasse 55, Hamburg, 20146 Germany
AB: An array of seven ocean bottom seismometers (OBS) and seven ocean bottom hydrophones (OBH) was installed for 5 1/2 month in 2001 in the Tyrrhenian Sea in the scope of the DFG(German research foundation)-project 'Tyrrhenian Sea'. Ten deep-focus events (between 150 and 300 km) with a hypocenter directly beneath the array and several teleseismic events were recorded. Multiple $PwP$-phases in the coda of the P-wave are typical for OBS recordings and are caused by multiple reflections in the water layer. These echos occur in regular intervals of 2 to 4 seconds depending on the thickness of the water layer. The amplitude and the waveform of the $PwP$-phases are controlled by the impedance contrast between water and sediments and by the structure and thickness of the sediment layer. The observed waveforms on the seismometer and the hydrophone were inverted simultaneously to derive a structural model for the shallow and deeper subsurface beneath some of the OBS stations.
DE: 3094 Instruments and techniques
DE: 3210 Modeling
DE: 7203 Body wave propagation
DE: 7220 Oceanic crust
SC: Seismology [S]
MN: 2003 Fall Meeting