Archive for the ‘Seismology’ category

Sedimentary deposits in the Istanbul’s Byzantine harbour

January 27, 2012

Bony et al. published an interesting study in Quaternary International about a Byzantine harbour (Theodosian harbour) which has been uncovered during excavations in Istanbul. The stratigraphic sequence goes back to 7000 BP. In the marine part of the sedimentary sequence, the authors interpreted high-energy deposit as tsunami deposits and related to the earthquake of 557 AD. You can find more info at http://dx.doi.org/10.1016/j.quaint.2011.03.031.

Source: nautarch.tamu.edu

Ground-base LIDAR on the North Anatolian Fault

December 25, 2011

Copyright CSIRO 2003 ©

Karabacak et al. have published a study of the surface creep along the North Anatolian Fault in the EPSL. They used a ground-based light detection and ranging (LIDAR) system on an unreported site where three manmade walls across the fault were monitored for 3 yrs between 2007 and 2009. They found that 50–70% of the yearly slip accumulates on the faults creep section. Please find more info here doi:10.1016/j.epsl.2011.01.017

7.2M earthquake in the Eastern Turkey

October 24, 2011

A magnitude 7.2 earthquake occurred in eastern Turkey on 23 October 2011 on noon local time. CNN reports that several buildings have collapsed in Van Province.

http://edition.cnn.com/2011/10/23/world/europe/turkey-earthquake/?hpt=wo_c2

Source: USGS

Earthquakes cycles recorded in calcite veins

February 8, 2011

Uysal et al. 2011 have published a new study about long term seismic cycles recorded in southwest Anatolian calcite veins. The study appeared in the Journal of Earth and Planetary Science Letters. They conducted high-resolution micro-sampling, high-precision U-series dating and micro- chemical analysis on an extensional vein system in a tectonically active area. U/Th ages of the vein system is in between 23.9±0.2 ka and 11.8±0.2ka. Their study offers an innovative means of constraining the absolute timing of late Quaternary seismic and inter-seismic events in Anatolia, Turkey. For more information, please refer to doi:10.1016/j.epsl.2010.12.039

From Uysal et al. (2011) © 2010 Elsevier

Geological history of western Turkey

August 22, 2010

A new study has been published in the Earth and Planetary Science Letters by van Hinsbergen et al. about the geological history of the western part of Turkey. They used African-Europe convergence amounts calculated from the Atlantic plate circuits and seismic tomography images from the west Anatolian mantle structure, and revealed the geological history since Cretaceous times in a context of convergence, subduction, collision and slab break-off. For further details please refer to  doi:10.1016/j.epsl.2010.07.024

Earthquake damage scenarios for Istanbul

July 26, 2010

Ansal et al., from Bogazici University, published a research study about a methodology for seismic microzonation and earthquake damage scenarios.  A pilot study is carried out to evaluate seismic damage in a district in Istanbul, which showed the significance of site characterization and site response analysis. Their results can be found in the journal of Soil Dynamics and Earthquake Engineering. doi:10.1016/j.soildyn.2010.06.004

Photo by Enric Marti (AA)

A review on Menderes Massif’s extensional history

June 8, 2010

A review about the structure and metamorphism of the well-researched Menderes Massif in western Turkey has been published in the latest issue of Earth-Science Reviews by van Hinsbergen. Menderes massif is among the largest continental extensional provinces in the world, and its extension is generally considered to have occurred along extensional detachments with a NE-SW stretching direction. However, restorations of the Early Miocene history show that these extensional detachments can only explain part of the exhumation history of the Menderes Massif. In this paper, author explains these restoration efforts and their main implications to the Western Anatolia. doi:10.1016/j.earscirev.2010.05.005

Image credit: J. Descloitres, NASA, MODIS Land Rapid Response Team