Towards permanent, multi-disciplinary seafloor observatories in the Sea of Marmara: Results from the Marmara Demonstration Mission of ESONET/NoE

The Marmara Demonstration Mission (april 2008 to september 2010) was conducted within the EU-funded ESONET Network of Excellence programme: i) to characterize the temporal and spatial relations between fluid expulsion, fluid chemistry and seismic activity in the SoM; ii) to test the relevance of permanent seafloor observatories for an innovative monitoring of earthquake related hazards, appropriate to the Marmara Sea specific environment; and iii) to conduct a feasibility study to optimize the submarine infrastructure options (fiber optic cable, buoys with a wireless meshed network, autonomous mobile stations with wireless messenger). A total of 6 cruises were conducted, allowing the selection of the optimum sites for the future multi-parameters sea-floor observatories: i) on the Istanbul-Silivri segment, located in the seismic gap immediately south of Istanbul where intense bubbling is observed; ii) on the Western High, where gas hydrates, oil and gas seeps from the Thrace Basin were found; and iii) at the entrance of Izmit Gulf near the western end of the surface rupture associated with the 1999 Izmit earthquake. A significant research effort has also been made during Marmara-DM for testing innovative sensors for monitoring variations in the geochemical and geophysical properties of gas emissions. The list of the sensors and the design of the observatories is described in a companion presentation, by Çagatay et al, [2011]. The results of the Marmara-DM demonstration mission support the necessity to monitor gas emission activity along with seismicity.