Archive for the ‘Glaciers of Turkey’ category

Remarkably extensive glaciation in Turkey near the Pleistocene-Holocene boundary

December 26, 2011

A new paper was published in GSA’s Journal of Geology by Zreda and others in November 2011. This is their media paragraph published in the journal’s web site: “Looking at how climate changed in the geological past can provide a useful perspective for studying modern climate change and for predicting climate changes in the next century. Dr Marek Zreda of the University of Arizona and his colleagues used mountain moraines to reconstruct the former glaciers and to determine climatic changes in Turkey at the beginning of the Holocene, the current interglacial epoch. They found that the glaciers were unusually large for that time, with snow lines lower than today by more than 1400 meters, implying a temperature 9°C lower than modern long-term average temperature. The main glacier melting phase lasted 500 years during which the ice margin retreated at the average rate of 1700 m per century, which is higher than modern gracier retreat rates computed over comparable time. This corresponds to the temperature increase at the rate of 1.4°C per century, which exceeds the global warming trend of the past century, 0.6°C, showing that natural causes can lead to fast and large climate changes, and that the magnitude and the rate of climate change observed in the past century are not unprecedented.” Please see more details and the paper here doi:10.1130/G32097.1

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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

Climate change during and after the LGM in Central Turkey

August 22, 2010

Dogan from Ankara University published a new paper in the Journal of Quaternary International about the fluvial responses of Kizilirmak terraces to Late Quaternary climatic changes. A numerical chronology was established by AMS dating of fluvial sediments and Ar–Ar dating of a basalt sample capping the youngest terrace (Late Pleistocene terrace), indicating that the main incision phase was completed at the end of the LGM (Last Glacial Maximum, ~21,000 years ago). It appears that the major climatic transition from the LGM to the Late Glacial gave rise to aggradation in the fluvial system, and this event seems to be consistent with the timing of the regression phase of pluvial lakes and the termination of paleoglacier advances in the high mountains of Anatolia. doi:10.1016/j.quaint.2009.08.004

Loss of ice cap on Mount Agri (Ararat) – Updated

June 8, 2010

Mount Agri (also known as Ararat) is the highest mountain of Turkey with a peak elevation of 5137 m. Today, it bears the only ice cap of the country. However, it is melting continuously! A recent study published in the Journal of Asian Earth Science showed that the Mount Agri ice cap has been lost its surface area by 29% since 1976 based on multi-temporal Landsat and ASTER satellite imagery. According to the author, the retreat rate is about 7 hectare per year. In the paper, it argued that there is a strong evidence that this retreat is mostly because of the current warming trend revealed from the meteorological stations from the region. It is added that similar shrinking trends are also evident from other Turkish glaciers. For more information, please refer to http://dx.doi.org/10.1016/j.jseaes.2011.12.009

Photo by Behesnilian