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| Titel |
Co-seismic gravity changes at TIGO/Concepcion after the M8.8 Maule Earthquake, Chile measured by absolute and superconducting gravimeters in comparison with a viscoelastic-gravitational model |
| VerfasserIn |
Hartmut Wziontek, Reinhard Falk, Herbert Wilmes, Peter Wolf, Hayo Hase, Armin Boer, Ivan Cona, Rongjiang Wang |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250055825
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| Zusammenfassung |
| The Transportable Integrated Geodetic Observatory (TIGO) near Concepcion is located only
80 km south from the epicenter of the devastating Earthquake of magnitude 8.8 occurred on
27 February 2010 in Maule region, Chile. Since November 2002, temporal gravity changes at
the geodetic fundamental station are recorded with highest precision by the superconducting
gravimeter RSG038, which is complemented since May 2006 by weekly absolute gravity
measurements with FG5-227. A comparison campaign with FG5-101 in April 2010
confirmed the high accuracy of the absolute gravity measurements after the Earthquake. The
combination of all gravity observations allowed us to reveal a co-seismic gravity decrease of
about 100nm-s2 from direct measurements for the first time. The separation from
the strong seasonal gravity signal of mostly hydrological origin was possible after
extrapolation of the temporal behavior of the pre-earthquake signal by singular
spectrum analysis (SSA) and by a composite annual cycle. Finally, the obtained gravity
change is compared with the response calculated from numerical model for the
deformation zone at the plate boundary between the subducting Nazca plate and
the South America plate by means of viscoelastic-gravitational dislocation theory. |
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