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| Titel |
Comparative analysis of geodynamic activity of the Caucasian and Eastern Mediterranean segments of the Alpine-Himalayan convergence zone |
| VerfasserIn |
Tamaz Chelidze, Lev Eppelbaum |
| 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 |
250079863
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| Zusammenfassung |
| The Alpine-Himalayan convergence zone (AHCZ) underwent recent transverse shortening
under the effect of collisional compression. The process was accompanied by rotation of
separate microplates. The Caucasian and Eastern Mediterranean regions are segments of the
of the AHCZ and are characterized by intensive endogenous and exogenous geodynamic
processes, which manifest themselves in occurrence of powerful (with magnitude of 8-9)
earthquakes accompanied by development of secondary catastrophic processes. Large
landslides, rock falls, avalanches, mud flows, etc. cause human deaths and great
material losses. The development of the aforesaid endogenous processes is set forth by
peculiarities of the deep structure of the region and an impact of deep geological
processes.
The Caucasus is divided into several main tectonic terranes: platform (sub-platform,
quasi-platform) and fold-thrust units. Existing data enable to perform a division of the
Caucasian region into two large-scale geological provinces: southern Tethyan and northern
Tethyan located to the south of and to the north of the Lesser Caucasian ophiolite suture,
respectively. The recent investigations show that the assessments of the seismic hazard in
these regions are not quite correct – for example in the West Caucasus the seismic hazard can
be significantly underestimated, which affects the corresponding risk assessments. Integrated
analysis of gravity, magnetic, seismic and thermal data enables to refine the assessment of
the seismic hazard of the region, taking into account real rates of the geodynamic
movements. Important role play the last rheological constructions. According to
Reilinger et al. (2006) tectonic scheme, the West flanking of the Arabian Plate
manifests strike-slip motion, when the East Caucasian block is converging and
shortening.
The Eastern Mediterranean is a tectonically complex region located in the midst of the
progressive Afro-Eurasian collision. The recent increasing geotectonic activity in this
region highlights the need for combined analysis of seismo-neotectonic signatures.
For this purpose, this article presents the key features of the tectonic zonation of
the Eastern Mediterranean. Map of derivatives of the gravity field retracked from
the Geosat satellite and novel map of the Moho discontinuity illustrate the most
important tectonic features of the region. The Post-Jurassic map of the deformation
of surface leveling reflects the modern tectonic stage of Eastern Mediterranean
evolution. The developed tectono-geophysical zonation map integrates the potential
geophysical field analysis and seismic section utilization, as well as tectonic-structural,
paleogeographical and facial analyses. Tectonically the map agrees with the earlier
model of continental accretion (Ben-Avraham and Ginzburg, 1990). Overlaying
the seismicity map of the Eastern Mediterranean tectonic region (for the period
between 1900 and 2012) on the tectonic zonation chart reveals the key features of the
seismo-neotectonic pattern of the Eastern Mediterranean. The results have important
implications for tectonic-seismological analysis in this region (Eppelbaum and Katz,
2012).
A difference in the geotectonic patterns makes interesting comparison of geodynamic activity
and seismic hazard of the Caucasian and Eastern Mediterranean segments of the
AHCZ. |
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