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| Titel |
Numerical survey of pressure wave propagation around and inside an underground cavity with high order FEM |
| VerfasserIn |
Sofi Esterhazy, Felix Schneider, Joachim Schöberl, Ilaria Perugia, Götz Bokelmann |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128672
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| Publikation (Nr.) |
 EGU/EGU2016-8680.pdf |
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| Zusammenfassung |
| The research on purely numerical methods for modeling seismic waves has been more and
more intensified over last decades. This development is mainly driven by the fact that on the
one hand for subsurface models of interest in exploration and global seismology exact
analytic solutions do not exist, but, on the other hand, retrieving full seismic waveforms
is important to get insides into spectral characteristics and for the interpretation
of seismic phases and amplitudes. Furthermore, the computational potential has
dramatically increased in the recent past such that it became worthwhile to perform
computations for large-scale problems as those arising in the field of computational
seismology.
Algorithms based on the Finite Element Method (FEM) are becoming increasingly
popular for the propagation of acoustic and elastic waves in geophysical models as they
provide more geometrical flexibility in terms of complexity as well as heterogeneity of the
materials. In particular, we want to demonstrate the benefit of high-order FEMs as they also
provide a better control on the accuracy. Our computations are done with the parallel Finite
Element Library NGSOLVE ontop of the automatic 2D/3D mesh generator NETGEN
(http://sourceforge.net/projects/ngsolve/).
Further we are interested in the generation of synthetic seismograms including direct,
refracted and converted waves in correlation to the presence of an underground cavity and the
detailed simulation of the comprehensive wave field inside and around such a cavity that
would have been created by a nuclear explosion. The motivation of this application
comes from the need to find evidence of a nuclear test as they are forbidden by the
Comprehensive Nuclear-Test Ban Treaty (CTBT). With this approach it is possible for us to
investigate the wave field over a large bandwidth of wave numbers. This again
will help to provide a better understanding on the characteristic signatures of an
underground cavity, improve the protocols for OSI field deployment and create solid
observational strategies for detecting the presence of an underground (nuclear) cavity. |
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