3-D crustal density model of the Sea of Marmara
<p>The Sea of Marmara, in northwestern Turkey, is a transition zone where the dextral North Anatolian Fault zone (NAFZ) propagates westward from the Anatolian Plate to the Aegean Sea Plate. The area is of interest in the context of seismic hazard of Istanbul, a metropolitan area with about 15&...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2019-06-01
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| Series: | Solid Earth |
| Online Access: | https://www.solid-earth.net/10/785/2019/se-10-785-2019.pdf |
| _version_ | 1818533503042584576 |
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| author | E. Gholamrezaie E. Gholamrezaie M. Scheck-Wenderoth M. Scheck-Wenderoth J. Bott O. Heidbach M. R. Strecker |
| author_facet | E. Gholamrezaie E. Gholamrezaie M. Scheck-Wenderoth M. Scheck-Wenderoth J. Bott O. Heidbach M. R. Strecker |
| author_sort | E. Gholamrezaie |
| collection | DOAJ |
| description | <p>The Sea of Marmara, in northwestern Turkey, is a transition zone where the
dextral North Anatolian Fault zone (NAFZ) propagates westward from the
Anatolian Plate to the Aegean Sea Plate. The area is of interest in the context
of seismic hazard of Istanbul, a metropolitan area with about 15 million
inhabitants. Geophysical observations indicate that the crust is
heterogeneous beneath the Marmara basin, but a detailed characterization of
the crustal heterogeneities is still missing. To assess if and how crustal heterogeneities are related to the NAFZ segmentation below the Sea of Marmara,
we develop new crustal-scale 3-D density models which integrate geological
and seismological data and that are additionally constrained by 3-D gravity
modeling. For the latter, we use two different gravity datasets including
global satellite data and local marine gravity observation. Considering the
two different datasets and the general non-uniqueness in potential field
modeling, we suggest three possible “end-member” solutions that are all
consistent with the observed gravity field and illustrate the spectrum of
possible solutions. These models indicate that the observed gravitational
anomalies originate from significant density heterogeneities within the
crust. Two layers of sediments, one syn-kinematic and one pre-kinematic with
respect to the Sea of Marmara formation are underlain by a heterogeneous
crystalline crust. A felsic upper crystalline crust (average density of 2720 kg m<span class="inline-formula"><sup>−3</sup></span>) and an intermediate to mafic lower crystalline crust (average
density of 2890 kg m<span class="inline-formula"><sup>−3</sup></span>) appear to be cross-cut by two large, dome-shaped
mafic high-density bodies (density of 2890 to 3150 kg m<span class="inline-formula"><sup>−3</sup></span>) of
considerable thickness above a rather uniform lithospheric mantle (3300 kg m<span class="inline-formula"><sup>−3</sup></span>). The spatial correlation between two major bends of the main Marmara fault and the location of the high-density bodies suggests that the
distribution of lithological heterogeneities within the crust controls the
rheological behavior along the NAFZ and, consequently, maybe influences
fault segmentation and thus the seismic hazard assessment in the
region.</p> |
| first_indexed | 2024-12-11T17:59:34Z |
| format | Article |
| id | doaj.art-1709bc1ed50f49ad9f9a860ea833f186 |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-12-11T17:59:34Z |
| publishDate | 2019-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-1709bc1ed50f49ad9f9a860ea833f1862022-12-22T00:55:57ZengCopernicus PublicationsSolid Earth1869-95101869-95292019-06-011078580710.5194/se-10-785-20193-D crustal density model of the Sea of MarmaraE. Gholamrezaie0E. Gholamrezaie1M. Scheck-Wenderoth2M. Scheck-Wenderoth3J. Bott4O. Heidbach5M. R. Strecker6GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, GermanyInstitute of Earth and Environmental Science, University of Potsdam, Potsdam, GermanyGFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, GermanyFaculty of Georesources and Materials Engineering, RWTH Aachen, Aachen, GermanyGFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, GermanyGFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, GermanyInstitute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany<p>The Sea of Marmara, in northwestern Turkey, is a transition zone where the dextral North Anatolian Fault zone (NAFZ) propagates westward from the Anatolian Plate to the Aegean Sea Plate. The area is of interest in the context of seismic hazard of Istanbul, a metropolitan area with about 15 million inhabitants. Geophysical observations indicate that the crust is heterogeneous beneath the Marmara basin, but a detailed characterization of the crustal heterogeneities is still missing. To assess if and how crustal heterogeneities are related to the NAFZ segmentation below the Sea of Marmara, we develop new crustal-scale 3-D density models which integrate geological and seismological data and that are additionally constrained by 3-D gravity modeling. For the latter, we use two different gravity datasets including global satellite data and local marine gravity observation. Considering the two different datasets and the general non-uniqueness in potential field modeling, we suggest three possible “end-member” solutions that are all consistent with the observed gravity field and illustrate the spectrum of possible solutions. These models indicate that the observed gravitational anomalies originate from significant density heterogeneities within the crust. Two layers of sediments, one syn-kinematic and one pre-kinematic with respect to the Sea of Marmara formation are underlain by a heterogeneous crystalline crust. A felsic upper crystalline crust (average density of 2720 kg m<span class="inline-formula"><sup>−3</sup></span>) and an intermediate to mafic lower crystalline crust (average density of 2890 kg m<span class="inline-formula"><sup>−3</sup></span>) appear to be cross-cut by two large, dome-shaped mafic high-density bodies (density of 2890 to 3150 kg m<span class="inline-formula"><sup>−3</sup></span>) of considerable thickness above a rather uniform lithospheric mantle (3300 kg m<span class="inline-formula"><sup>−3</sup></span>). The spatial correlation between two major bends of the main Marmara fault and the location of the high-density bodies suggests that the distribution of lithological heterogeneities within the crust controls the rheological behavior along the NAFZ and, consequently, maybe influences fault segmentation and thus the seismic hazard assessment in the region.</p>https://www.solid-earth.net/10/785/2019/se-10-785-2019.pdf |
| spellingShingle | E. Gholamrezaie E. Gholamrezaie M. Scheck-Wenderoth M. Scheck-Wenderoth J. Bott O. Heidbach M. R. Strecker 3-D crustal density model of the Sea of Marmara Solid Earth |
| title | 3-D crustal density model of the Sea of Marmara |
| title_full | 3-D crustal density model of the Sea of Marmara |
| title_fullStr | 3-D crustal density model of the Sea of Marmara |
| title_full_unstemmed | 3-D crustal density model of the Sea of Marmara |
| title_short | 3-D crustal density model of the Sea of Marmara |
| title_sort | 3 d crustal density model of the sea of marmara |
| url | https://www.solid-earth.net/10/785/2019/se-10-785-2019.pdf |
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