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| Titel |
Comparison of the bedrock depth from array measurements of Rayleigh waves associated with microtremor and seismic profile obtained the Seismic Reflection Data, Eskisehir Basin, Turkey |
| VerfasserIn |
Muammer Tun, Savas Karabulut, Oguz Ozel |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102854
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| Publikation (Nr.) |
 EGU/EGU2015-2256.pdf |
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| Zusammenfassung |
| Ground motion estimation for future earthquakes is one of the most challenging problems in
seismology and earthquake engineering. The bedrock depth has a considerable seismic risk
for the urban area of Eskişehir. In this study, multiple station microtremor measurement
methods which are more practical, non-distructive, fast and economical compared to seismic
reflection method were implemented. These method using microtremor recordings have
become a very useful data for microzonation studies because of their simple acquisition and
analysis. Extensive ambient noise measurements were performed in the basin of Eskisehir
from June 2010 to spring 2012. We use data recorded by a broadband seismometer and
digitizer CMG-6TD, Guralp seismometer. Some of the measurement locations,
the CMG-6TD sensor was located into 30 cm-deep holes in the ground to avoid
strongly wind-generated, long-period noise. Dominant frequency (f), bed-rock depth
(h) and shear-wave velocity (Vs) were determined from Spatial Autocorrelation
(SPAC) methods. With the SPAC Method, it is possible to constrain the velocity
structure underlying the site using microtremor array measurements. The results
obtained were compared to the 96-channel seismic reflection data with explosive
energy source. Several seismic reflection surveys with P-Gun seismic source have
been performed on the same place with array measurements. We used two types
of seismic sources: 36 cartridge Gun. Shot interval was 10 meters, group interval
(one geophone per group, 48 geophones in total) was 10 meters, near offset was
10 meters, far offset was 480 meters, CDP interval was 5 meters. We adapted the
“Off-End Spread” technique while using the Gun. Reflection images within the
sedimentary section correlate well with the velocity structure obtained from SPAC. |
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