Monitoring Earthquake Activity At Marmara Region By Multidisciplinary Studies And Research On Probable Effects On Istanbul Coastal Zone/ Continental Shelf (MAZDDA)

The main objective of the project is to monitor earthquake activity in the Marmara Region by multi-disciplinary studies and to carry out research on the probable effects of a future earthquake on the Istanbul coastal zone/continental shelf.  In order to achieve this objective, Earth and Marine Sciences Institute (EMSI) will contribute to pre-disaster studies in collaboration with the financial supporter of the project, which is Istanbul Metropolitan Municipality (IMM), and will give information flow based on its scientific findings obtained, by the continuous geochemical and geophysical studies it carries within the region.  Figure 1 shows the study area in detail.

As a main target of the study, EMSI will focus on landslides/earthquakes in the land and coastal zone. In consequence to a future earthquake devastating Istanbul, submarine landslides may occur; there may be potential coastal zones affected as a result of submarine sediment flow or slide and these may be related to continental landslides. All these will be the subject of a pilot study that will be carried out by EMSI at the Avcilar-Zeytinburnu region within the scope of this project.

As a complementary study of on-going efforts of IMM, S wave velocities will be calculated within the region by microtremor array measurements approach (spatial autocorrelation method). The suitability of this method was already proven in studies carried out by EMSI both in Yalova and Kocaeli Provinces.

The project will be carried to include the following work packages.
•          To monitor micro seismic activity (earthquakes of magnitude 1 and larger) in Marmara and particularly in the vicinity of Istanbul by a network of micro-seismologic stations operated by EMSI, which are unique at national basis.  This information is not available by national observation centers because their magnitude threshold is larger than 2,5.

•          To prepare weekly monitoring, evaluation and interpretation reports on anomalies in content of soil radon gas, changes in physical and chemical characteristics of cold/hot spring water sources, along with micro-seismic activity, and to deliver them to IMM, to give information on any anomaly within the region so that disaster coordination and planning can be done to become on the alert.

•          To do study the basement properties of different geological units, EMSI will realize microtremor array measurements and will produce hazard maps and contribute to the micro-zoning studies at different geologic units.

•          To study the shallow sea area (0-100m) and mapping the sediment packets which are related with the possible landslides, between Silivri-Sarayburnu by geophysical methods, EMSI will collect seismic data, multi-beam and side scan sonar data sets.
•          To add deformation as an additional dimension in landslide studies in the coastal region bounded by Avcilar and Büyük Çekmece and to determine the areas affected beneath the sea, GPS surveys will be realized and the results will be combined with the outputs of the geophysical studies in the shallow sea.

Figure 1. Red and black lines show the location of seismic lines. On the land, red dots indicate the location of planned micro-tremor measurements and landslide monitoring sites.

Duration: 18.04.2007 – 28.11.2008