 |
| Titel |
Sea level feedback for 2004 Sumatra and 2010 Maule earthquakes. |
| VerfasserIn |
Filippo Santolini, Gabriele Cambiotti, Roberto Sabadini |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250054649
|
|
|
|
|
|
| Zusammenfassung |
| The co-seismic gravitational perturbations of large earthquakes can be studied on a
global scale with the aid of Gravity Recovery and Climate Experiment (GRACE)
Level 2 data time series. For submarine earthquakes as that of 2004 Sumatran, the
gravitational effect of the ocean water, displaced away from the uplifted crust, is quite
important as pointed out by previous studies by including in the modelling a global
ocean layer. When a realistic ocean is instead considered, taking into account the
shape of continents, new problems arise. Indeed, the realistic ocean mixes different
wavelength perturbations and the solution of the sea level equation converges if short
wavelength perturbations are also included. In order to investigate this issue and quantify
the minimum threshold at which the convergence is obtained, we calculate the
sea level feedback of the realistic ocean involving shorter and shorter wavelength
perturbations until its contribution to long wavelength perturbations remains stable. If the
convergence is not achieved, the error in the modelled co-seismic gravity anomalies for the
2004 Sumatran earthquake can be as large as the uncertainty in the GRACE data
analysis, making meaningless the comparison between models and data. Having
clarified this issue we point out the differences between the sea level feedback due
to global and relistic oceans. We present also results for the 2010 Maule (Chile)
earthquake. |
|
|
|
|
|
|