The positive temperature anomaly as detected by Landsat TM data in the eastern Marmara Sea (Turkey): possible link with the 1999 Izmit earthquake

Abstract

A long (∼15 km) and narrow (∼4 km) offshore positive temperature anomaly (∼1.7° C) is observed in the Landsat Thematic Mapper (TM) thermal infrared (TIR) image acquired the day following the large İzmit earthquake (Mw 7.4) of 17 August 1999, in eastern Marmara Sea, Turkey. The earthquake was generated along the North Anatolian Fault, which ruptured for about 150 km, and the anomaly formed at the western termination of this rupture. Discussions of this anomaly may develop by processes different than the seismic activity and considerations on fault geometry and sea bathymetry characteristics suggest that the anomaly may result from aftershock activity near the western end of the earthquake fault. The formation of the anomaly requires the addition of a large quantity of hot waters to the sea. The ascent to the sea bottom of fault‐driven hot fluids (seismic pumping) and formation of thermal plumes may be the processes by which the sea surface temperature increased. Recent works and the present study suggest that TIR data analysis may be used as a tool in seismological studies.

Acknowledgments

The author is grateful to his colleagues Dr Onur Köse, from the Yüzüncü Yıl University, Van, Turkey, and Dr Kenan Tüfekçi, from MTA, for allowing him to use satellite data the Eurimage Company provided after the 1999 İzmit earthquake. Dr Orhan Gökdemir, from Hacettepe University, converted some satellite data to bitmaps. The author is grateful to his colleague Dr Yurdal Genç, from Hacettepe University, for his very constructive remarks and criticism. The author also would like to thank Professor Arun Saraf and two anonymous referees whose suggestions and comments improved the manuscript.