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| Titel |
FaultLab: Results on the crustal structure of the North Anatolian Fault from a dense seismic network |
| VerfasserIn |
David Thompson, Sebastian Rost, Greg Houseman, David Cornwell, Niyazi Türkelli, Uğur Teoman, Metin Kahraman, Selda Altuncu Poyraz, Levent Gülen, Murat Utkucu, Andrew Frederiksen |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080076
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| Zusammenfassung |
| The North Anatolian Fault Zone (NAFZ) is a major continental strike-slip fault
system, similar in size and scale to the San Andreas system, that extends ~1200 km
across Turkey from the Aegean coast on the west to the Lake Van region in the east.
FaultLab is a multidisciplinary project that aims to better understand deformation
throughout the entire crust in the NAFZ, in particular the expected transition from narrow
zones of brittle deformation in the upper crust to broad shear zones in the lower
crust/upper mantle and how these features contribute to the earthquake loading cycle. The
project incorporates broadband seismology, satellite geodesy, structural geology and
numerical modelling in order to give an unprecedented view of the dynamic state of
the NAFZ in the vicinity of the devastating 1999 Izmit and Düzce earthquakes.
This contribution will discuss the first results from the seismic component of the
project, a 73 station network encompassing the northern and southern branches of the
NAFZ in the Sakarya region. Deployed in May 2012, the Dense Array for North
Anatolia (DANA) is arranged as a 6Ã11 grid with a nominal station spacing of 7 km,
with a further 7 stations located outside of the grid. Receiver function analysis
will provide estimates of bulk crustal properties, along with information regarding
heterogeneity at depth (dipping interfaces/anisotropy). With the excellent resolution
afforded by the DANA network, we will present results using the technique of
teleseismic scattering tomography. The method uses a full waveform inversion of
teleseismic signals coupled with array processing techniques to infer the properties
and location of small-scale heterogeneities (with scales on the order of the seismic
wavelength) within the crust. Images obtained using these methods will provide evidence
for how the deformation is distributed within the fault zone at depth, providing
constraints that can be used in conjunction with structural analyses of exhumed fault
segments elsewhere, and models of geodetic strain-rate across the fault system. By
linking together results from the complementary techniques being employed in the
FaultLab project, we aim to produce a comprehensive picture of fault structure and
dynamics throughout the crust and shallow upper mantle of this major active fault zone. |
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