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| Titel |
Study of the factors affecting the karst volume assessment in the Dead Sea sinkhole problem using microgravity field analysis and 3-D modeling |
| VerfasserIn |
L. V. Eppelbaum, M. Ezersky, A. Al-Zoubi, V. Goldshmidt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7340
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| Digitales Dokument |
URL |
| Erschienen |
In: Geophysical monitoring of the near-surface by electromagnetic and other geophysical methods ; Nr. 19 (2008-11-14), S.97-115 |
| Datensatznummer |
250014158
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| Publikation (Nr.) |
 copernicus.org/adgeo-19-97-2008.pdf |
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| Zusammenfassung |
| Thousands of sinkholes have appeared in the Dead Sea (DS) coastal area in
Israel and Jordan during two last decades. The sinkhole development is
recently associated with the buried evaporation karst at the depth of 25–50 m
from earth's surface caused by the drop of the DS level at the rate of
0.8–1.0 m/yr. Drop in the Dead Sea level has changed hydrogeological
conditions in the subsurface and caused surface to collapse. The
pre-existing cavern was detected using microgravity mapping in the Nahal
Hever South site where seven sinkholes of 1–2 m diameter had been opened.
About 5000 gravity stations were observed in the area of 200×200 m2 by the use of Scintrex CG-3M AutoGrav gravimeter. Besides the conventional
set of corrections applied in microgravity investigations, a correction for
a strong gravity horizontal gradient (DS Transform Zone negative gravity
anomaly influence) was inserted. As a result, residual gravity anomaly of
–(0.08÷0.14) mGal was revealed. The gravity field analysis was
supported by resistivity measurements. We applied the Emigma 7.8 gravity
software to create the 3-D physical-geological models of the sinkholes
development area. The modeling was confirmed by application of the GSFC program
developed especially for 3-D combined gravity-magnetic modeling in
complicated environments. Computed numerous gravity models verified an
effective applicability of the microgravity technology for detection of
karst cavities and estimation of their physical-geological parameters. A
volume of the karst was approximately estimated as 35 000 m3. The
visual analysis of large sinkhole clusters have been forming at the
microgravity anomaly site, confirmed the results of microgravity mapping and
3-D modeling. |
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