ESONET NoE - Marmara Sea Observatory

Transcription

1 The Marmara Sea is an intra-continental marine basin between the Aegean and Black seas. It is in a tectonically very active region located on the North Anatolian Fault (NAF) zone (Şengör, 1979; Barka, 1992; Straub et al., 1997; Okay et al., 1999, 2000; Le Pichon et al., 2001; Şengör et al., 2004). The NAF is a major transform-plate boundary that has produced devastating historical earthquakes along its 1600 km length (Ambraseys and Finkel, 1995). The most active northern branch of the NAF cuts across the Marmara in an E-W direction and continues westward into the NE Agean Sea (Fig. 19). The Marmara Sea has three ~1250 m-deep strike-slip basins between km-wide northern shelf and a 40 km-wide southern shelf. The deep basins are separated by -450 to -600 m deep, NEtrending transpressional ridges. The shelf break is at about -100 m water depth. The slopes leading to the deep basins are steep (>18º) and carry the scars of many paleo-landslides and submarine canyons (Fig.1). They also have some unstable areas near the shelf break and in the upper slope that may slide during future seismic events. The earthquake events along the NAF have a westward progression with sixty sequence of rupturing toward Istanbul, in which one event promoting the next. After the 1999 Izmit and Düzce earthquakes, the next large (Mw> 7) earthquake is expected in the Marmara Sea close to Istanbul, an important cultural centre and a mega-metropole with 15 million inhabitants (Parsons et al., 2000). There are also large faults with dip-slip component in the south, near the edge of the southern shelf and Imralı submarine platform which in the event of their rupture, would cause tsunamis in the Marmara Sea. The earthquake activity in the Marmara Sea has produced more than 30 tsunami events in the past two millennium, with heights up to about 6 m in the coastal areas (Yalçıner et al., 2002). Most of these tsunamis have probably been caused by submarine land slides. The coastal areas and freshwater reservoirs providing Istanbul with water are under tsunami risk. The Büyük Çekmece Lake on the northern coast of the Marmara Sea is in location particularly prone to tsunamis. This lake provides more than 15% of Istanbul s drinking water. ROV video surveys of the sea floor during the R/V Meteor Leg M44-1 (Halbach et al., 2000) and R/V Le Atalante (Armijo et al., 2005) have proven active venting of methane-rich fluids from the fault on the Western Ridge and the SE corner of the Tekirdağ Basin (Fig. 20). These sites are also characterized by black bacterial mats, chemosynthesis-dependent fauna consisting of mainly bivalves (abundant mytilids), echinids and crustacea and carbonate crusts (Fig. 20). The ROV video observations show that the deep basin floors are commonly marked with very densely distributed burrows, indicating a high benthic faunal activity. The Marmara Sea is also interesting in terms of its oceanographic setting. It is connected to the low salinity (S=18 ) Black Sea via the İstanbul (Bosphorus) Strait and to the normal marine (S=38.5 ) Aegean Sea via the Canakkale (Dardanelles) Strait; the two straits have sill depths of -65 and -35 m, respectively. There is a permanent two-layer flow in the straits and the Marmara Sea with the halocline located at -25 m (Ünlüata et al., 1990; Besiktepe et al., 2004). The Black Sea waters enters the Marmara Sea as a jet through the İIstanbul Strait and forms the upper layer (Besiktepe at al., 1994). The upper layer water circulates in the Marmara Sea as an anticyclonic gyre at velocities of cm/s Marmara Sea as an anticyclonic gyre at velocities of cm/s and flows out through the Marmara Sea as an anticyclonic gyre at velocities of cm/s and flows out through the Çanakkale Strait as the surface current. The Mediterranean water enters the Marmara Sea as an undercurrent and dips into the Tekirdağ Basin and forms the lower water layer with a potential temperature of 14.5 C (Ünlüata et al., 1990; Besiktepe et al., 1993). Its eastward flow towards the 1/10

2 Istanbul Strait is somewhat hindered by the pressure ridges. The slow circulation, coupled with the microbial degradation of the organic matter, results in a gradual depletion of oxygen in the lowerlayer to 2-3 mg O2/l in the Çınarcık Basin. The renewal time of surface and the deep waters is estimated to be 4-5 months and 6-7 s, respectively (Ünlüata et al., 1990, Beşiktepe et al., 1993). The Sea of Marmara region is densely populated and industrialized with more than Turkey s 20% population and 50% industry located in its drainage basin. The municipal and industrial inputs from its drainage basin, together with nutrient and contaminate inputs from the Black Sea, have polluted the Marmara Sea in the last 40 s (Orhon et al., 1994; Polat and Turgut, 1995). Its high tectonic activity with catastrophic earthquakes, submarine landslides and resulting tsunamis, as well as its special oceanographic setting as a gateway between the Mediterranean and Black Seas, makes the Marmara Sea a natural laboratory for multidisciplinary scientific research and training area for young scientists. The significance of the Marmara Sea seismic gap for earthquake risk assessment and mitigation The westward progression of major ruptures along the NAF (Barka, 1996), culminating with the 1999 destructive earthquake events, leaves a 170 km long seismic gap along the Sea of Marmara capable of generating large earthquakes (Reilinger et al., 2000; Hubert-Ferrari et al., 2000).The last destructive earthquakes occurred at the western and eastern edges of the Marmara basin (i.e., 1912 Ganos and 1999 İzmit and Düzce earthquakes). It is likely that fault ruptures will fill this gap in the next decades (Toksöz et al., 1999; Pinar et al., 2001; Öncel and Wyss, 2000; Parsons et al., 2000; Atakan et al., 2002). The hazard facing Istanbul and adjacent areas varies widely depending on where and how the predicted Marmara seismic rupture will take place. This region of the North Anatolian Fault is thus critical to our understanding of fault interactions, stress build-up during seismic cycle and seismic hazard in the Istanbul area. Estimates of the slip rate, distribution of motion, microseismicity along the strands of the NAF, detection of fluid outflow and the analysis of how it relates to the seismic activity can help reach a realistic assessment of seismic hazards for this densely populated area of Turkey. Seafloor observatories would offer earth scientists and oceanographers working in this region unique new opportunities:. to study multiple, interrelated processes over time scales ranging from seconds to decades;. to conduct comparative studies of regional processes and spatial characteristics;. to map basin-scale structures using time-series measurements. Scientific objectives The overall objectives of the proposed activity in the Marmara region are mainly focused to conduct comparative studies of multiple, interrelated processes driven by fault movement. These studies should be carried out giving high priority to those areas which are more prone to seismic hazard. 2/10

3 Figure 1 : Morphotectonic map of the Marmara Sea, showing the location of the proposed observatory sites. Figure 2 : Cold fluid venting, carbonate mound, black bacterial mats and benthic fauna (mainly bivalves) as white shells from the SE Tekirdag Basin, proposed observatory site 2 (R/V Le Atalante cruise, Marmarascarps project; Armijo et al., 2005). The fish is 10 cm long. See Fig. 1 for location of the site. The lack of extensive, more-or-less continuous time-series measurements is probably one of the most serious limits to understanding of long-term trends and cyclic changes of fault behaviour, as well as episodic events such as major earthquakes or submarine landslides. The key point to address these issues will be obtaining time-series observations at different locations along the North 3/10

4 Anatolian fault system. The results of these observations could be integrated in theoretical models that will be used to predict fault behaviour and to guide new experiments. The science topics and themes that can be tackled using ocean observatory capabilities, span a wide range of studies. The following outlines a set of scientific issues and a selection of questions for which ocean observatories could enable major breakthroughs by using new technology and innovative experimental approaches: 1) Earthquake processes: As fault blocks move, they can lock and accumulate stress that can be released quickly in the form of earthquakes (seismic deformation) or as creeping motion (aseismic deformation). Monitoring the seismic and aseismic deformation over an extended period of time will enable scientists to understand how and when strain is released along the NAF system. These data will be used to assess and mitigate the geological risk. Observatories can facilitate contemporaneous measurements of different parameters over long time scales, which is essential to their characterization and understanding. 2) Sedimentation and sediment transport: normal hemi-pelagic sedimentation, and sedimentation triggered by storm events, floods, and earthquakes; 3) Water column studies; 4) Fluids, chemistry, and ecological characterization; 5) How often, and in what pattern and quantity, is fluid delivered from the fault to the sea? 6) What are the primary heat transfers, chemical and biological consequences of fluid outflow along the fault system? 7) To what degree does fluid venting influence the physical, chemical and biological character of the overlying water column? What is the relative importance of episodic vs. steady state outputs? Each question is an important research focus in its own right; taken together they encompass the major interactive processes operative along the global fault system. Significant observatory sites 1) Eastern edge of the Çınarcık Basin: the 1999 earthquake rupture extends up to here. The next earthquake rupture is expected to involve the fault segment in this basin and its westward extension at least all the way to the Central Basin (Le Pichon et al., 2001). This basin is also prone to submarine landslides and tsunamies. It is also the location where the deep waters Mediterranean origin move towards the Istanbul Strait on their way to the Black Sea, and where the pollutants and nutirents from the Istanbul Metropolitan area and the Black Sea begin affecting the deep basinal areas of the Marmara Sea. 2) Tekirdağ Basin: Tekirdağ Basin and the Western Ridge is intersected by the main Marmara fault with fresh scarps and a prominent deep furrow, where fluid escape, bacterial mats, mineral crusts and associated benthic life have been observed (Fig. 20) The western extension of the main Marmara fault in the Tekirdağ Basin connects with the onshore Ganos Fault, which ruptured during 1912 earthquake. The Tekirdağ Basin is also the first location where the waters of Mediterranean origin from the Çanakkale Strait (Dardanelles) descend into the deep Marmara basinal areas. 4/10

5 3) The Eastern Ridge: this ridge separates the Çınarcık and Central Basins and constitutes a part of the seismic gap in the Marmara Sea. Here, it is important to monitor micro-seismic activity, with a view to determine if the fault segment is locked or creeping. The main objectives in these locations are to monitor: 1) micro-seismic activity, 2) fluid escape and its relation to sesimic activity, benthic organic activity and ecology, 3) sedimentary processes related to seismic activity, submarine landslides, resulting tsunamis and turbidity currents, and 4) to obtain time-series oceanographic data (T, salinity, dip currents, turbidity, oxygen content), which are important for understanding the deep circulation dynamics and for monitoring ecological changes and effects of pollution in the deep Marmara Sea. Existing national and international programs on the Marmara Sea There are no sea-floor observatory programmes presently being carried out in the Marmara Sea. However, there are several ongoing collaborative international research projects, related to mainly the earthquake geology and geophysics. 1) MARMARASCARPS project: IPGP, CNRS, IFREMER, ITU, IFREMER and other French Groups ) MARMARA VT project: CNRS (CEREGE, PEPS), COLLEGE DE FRANCE, ITU, IFREMER, CNRS FUB, GEOMAR, PEPS ) Inception, geometry and evolution of a major continental transform: the North Anatolian Fault in the Sea of Marmara and the surrounding regions : Italian Ministry of Education, Univ. and Research. ISMAR, ITU, Bologna, Rome and Trieste Univ. (Italy) ) Earthquake risk assessment in the Marmara Sea: ITU-EMCOL, ISMAR, Istanbul Metropolitan Municipality, ) EMCOL (Eastern Mediterranean Centr for Oceanography and Limnology): ITU, EC-FP-6 project ) MARNAUT (investigation of cold seeps and potential landslide areas with Nautile submersible) CNRS (CEREGE, PEPS), College de France, ITU, MAM, IFREMER, FUB, GEOMAR, ) Sediment Geochemistry Atlas of the Marmara Sea, ITU supported by TUBITAK, Project no.103y053. Participants ITU-EMCOL (Turkey) ISMAR (Italy) COLLEGE DE FRANCE 5/10

6 Financial support Financial support from the City Council of Istanbul and Istanbul Metropolitan Municipality is possible. 6/10

7 Regional consortium of users TURKEY User Name User Category User Interest ITU-EMCOL Reserch and 12, 9, educational 18 Istanbul Metropol. Municipality (IBB) Coordination Centre for Disaster Mitig. (AKOM) SHOD (Dept. Nav. Hydrog. Oceanogr. Kandilli Observ. Boğaziçi Univ. Ins. of Marine Sci. Mid. East Tech. Univ. Inst. Marine Sci.&Tech. 9 Eylül Univ. Inst. Marine Sci.&Manag. Istanbul Univ. Marmara Research Centre, TÜBİTAK General Direct. Disaster Mitigation MTA General Directorate Ministry of Environment Turkish Research (TUDAV) Marine Found... Research Reseach Research Research Research Public 5, 8, 12, 18 5, 12, 17 10, 12, maritim e safety Parameter Location Real time Forecast Timescale Audio-visual displays, near real time Marmara 1 day to data, all aspects of seismic, phys. s and chem. and biological observations Audio-visual displays, near real time Marmara Months to data, Audio-visual displays, near real time data, seismic data Audio-visual displays, near real time data, all aspects of physical and chemical observations 12, 13 All aspects of seismic, physical, 2, 9, 4, All aspects of seismic, physical 13 4, 12, 13 All aspects of seismic, physical, 4, 12,13 All aspects of seismic, physical, 4, 12 All aspects of seismic, physical, 12 All aspects of seismic, physical, 12 All aspects of seismic, physical and chemical observations 2, 4, 5, All aspects of seismic, physical, 6,7, 10,12, 17, 18 4, 5, 7, 8, 17, 18 All aspects of seismic, physical, s Marmara Days to months Marmara 1 day to months Marmara 1day to one month Marmara 1 day to month Marmara Month to Marmara Month to Marmara Month to Marmara 1 day to month Marmara Month to Marmara Month to Marmara Month to Statistic Comments Geohazards, climate change, environmental pollution Earthquake risk mitigation, environmental protection, water quality Earthquake risk mitigation, environmental protection Oceanography and geophysical research Earthquake seismology Oceanography and geophysical research Oceanography and geophysical research Oceanography and geophysical research Marine environmental pollution and geophysical research Earthquake risk mitigation Marine geological and geophysical research Environmental protection, water quality, fisheries, biodiversity, pollution Environmental protection, biodiversity and nature protection, oil and other contaminated pollution 7/10

8 Selected References for Node description and participants: Ambraseys, N.N., Finkel, C.F. (1995). The seismicity of Turkey and adjacent areas, a historical review, , 240pp, Eren, İstanbul. Armijo, R., Pondard, N., Meyer, B. and Uçarkuş, G., Mercier de Le pinay, B., Malavieille, J., Dominguez, S., Gustcher, M-A., Schmidt, S., Beck, C., Çağatay, N. Çakır, Z., Caner, I., Eris, K and Natalin, B., Ozalaybey, S., Tolun, L. (2005). Submarine fault scarps in the Sea of Marmara pull-apart (North Anatolian Fault): Implications for seismic hazard in Istanbul. Geochemistry, Geophysics, Geosystems, 6: Atakan K., A. Ojeda, M. Meghraoui, A.A. Barka, M. Erdik, A. Bodare, Seismic Hazard in Istanbul following the 17 August 1999 İzmit and 12 November 1999 Düzce Earthquakes, Bulletin of the Seismological Society of America, 92 (2002) Barka, A.,1992. The North Anatolian Fault Zone. Ann. Tecton., 6: Barka, A.,1996. Slip distribution along the North Anatolion Fault associated with large earthquakes of the period 1939 to 1967, Bull. Seismol. Soc. Am Barka, A.A and Kadinsky Cade, K. (1988). Strike-slip fault geometry in Turkey and its influence on earthquake activity, Tectonics 7, Becel, A.P., Charvis, P., de Voogd, B., Galv, A.,Hirn, A., Laigle, M., Lepine, J., Murai, Y., Ozalaybey, S.,Sapin, M., Shmamura, H., Singh, S., and Taymaz, T. (2004). Seismic structure and activity of North Anatolian Faut in the Sea of Marmara from the Seismarmara Leg 1 Seismic Survey. EOS Trans., 85(47), Fall Meetng., Suppl., Abstract S52A-04. Beşiktepe, S., Özsoy, E., Ünlüata, Ü. (1993). Filling of the Marmara Sea by the Daradanelles lower layer inflow. Deep-Sea Research., 49(9): Beşiktepe, S., Sur, H.İ., Özsoy, E., Latif, M.A., Oğuz, T., Ünlüata, Ü. (1994). Circulation and hydrography of the Marmara Sea. Prog. Oceanography, 34: Çagatay, M.N., Görür, N., Algan, O., Eastoe, C.S., Tchapalyga, A., Ongan, D., Kuhn, T. Kuşcu, İ., Late Glacial-Holocene palaeoceanography of the Sea of Marmara: timing of connections with the Mediterranean and the Black Sea. Marine Geology, 167(3-4): Çağatay, M.N., Görür, N. Polonia, A., Demirbağ, E., Sakınç, M.. Cormier, M.-H., Capotondi, L., McHugh, C., Emre, Ö., Eriş, K. (2003). Sea level changes and depositional environments in the İzmit Gulf, eastern Marmara Sea, during the late glacial-holocene period. Marine Geology, 202, Çağatay, M.N., Özcan, M., Güngör, E. (2004). Pore water and sediment geochemistry in the Marmara Sea (Turkey): early diagenesis and diffusive fluxes. Geochemistry: Exploration, Environment, Analysis (Geol. Soc. London), 4: Gökaşan, E., Ustaömer, T., Gazioğlu, C., Yücel, Z.Y., Öztürk, K., Tur, H., Ecevitoğlu, B., and Tok, B., (2003): Active tectonics of the Marmara Sea: Morpho-tectonic evolution of the Marmara Sea inferred from multi-beam bathymetric and seismic data, Geo-Marine Letters 23, Görür, N., Çağatay, N.,Sakinç, M., Sumengen, M., Şentürk, K., Yaltirak, C., Tchpalyga, A. (1997): Origin of the Sea of Marmara as deduced from Neogene to Quaternary paleogeographic evolution of its frame, Inter. Geol. Review 39, Görür, N.and Çağatay, M.N. (2000) The Sea of Marmara: A deep intracontinental basin formed by North Anatolian Fault activity. In: H. Gökçekuş (ed.), Proceedings of the International Conference on Earthquake Hazard and Risk in the Mediterranean Region, Near East Univ. Northern Republic of Northern Cyprus,Lefkoşa, vol. 1, pp October marmara-observatory 8/10

9 ESONET NoE Annex I Description of Work / APPENDIXES Halbach, P. et al. (2000). Report and preliminary results of METEOR Cruise M44/1. In: Östliches Marmara Meer-Nörtliches Rotes Meer 1999, Cruise No. 44. METEOR Berichte, University of Hamburg, pp. Hubert-Ferrari A., A. Barka, E. Jacques, S.S. Nalbant, B. Meyer, R. Armijo, P. Tapponier, G.C.P. King, Seismic hazard in the Marmara Sea region following the 17 August 1999 Izmit earthquake, Nature 404 (2000) İmren, C., Le Pichon, X., Rangin, C., Demirbağ, E., Ecevitoğlu, B., Görür, N.,(2001): The North Anatolian Fault within the Sea of Marmara: a new interpretation based on multi channel seismic and multi beam batymetry data. Earth and Planetary Science Letter 186, Le Pıchon, X., Chamot-Rooka, N., Noomen, R., Veis, G., Cinematique de I'Anatolie- Egee par rapport a I Europe a partir d une combinasion des mesures de triangulation geodesique sur 80 ans aux measures de type satellite Laser Ranging (SLR) resentes C.R. acad des Sci. 318 Ser.II Le Pıchon, X., Şengör, A.M.C., Demirbağ, E., Rangın, C., İmren, C., Armıjo, R., Görür, N., Çağatay, N., Mercıer De Lepınay, B., Meyer, B., Saatçiler, R., Tok, B., (2001): The active main Marmara Fault, Earth and Planetary Science Letters. 192, Le Pichon, X, Şengör, A.M.C., Demirbağ, E., Rangin, C., İmren, C. (2000). Marine Atlas of the Sea of Marmara. Ifremer. McClusky, S., Ballassanian, S., Barka, A., Demir, C., Ergintav, S., Georgiev, I., Gürkan, O., Hamburger, M., Hurst, K., Kahle, H., Kastens, K., Kekelidze, K., King, R., Kotzev, V., Lenk, O., Mahmoud, S., Mishin, A., Nadariya, M., Ouzounis, A., Paradissis, D., Peter, Y., Prilepin, M., Reilinger, R., Sanlı, I., Seeger, H., Tealeb, A., Toksöz, M.N.; Veis, G. (2000). Global positioning system constraints on plate kinematics and dynamics in the Eastern Mediterranean and Caucasus, J. Geophys. Res. 105: McKenzie, D.P., Active tectonics of Mediterranean region. Geophys. J. R. Ast. Soc. 30, Orhon, D., Uslu, O. Meriç, S., Salihoğlu, I., Filibeli, (1994). Waste-water management for Istanbul: basis for treatment and disposal. Environ. Pollut., 84: Öncel O. and M. Wyss, The major asperities of the 1999 M w = 7.4 Izmit earthquake defined by the microseismicity of the two decades before it, Geophysical Journal International 143 (2000) Parsons, T., Shinji, T., Stein, R.S., Barka, A., Dieterich, J.H., Heightened odds of large earthquakes near Istanbul: an interaction based probability calculation. Science, 288: Pinar A., Y. Honkura, K. Kuge, Seismic activity triggered by the 1999 Izmit earthquake and its implications for the assessment of future seismic risk, Geophysical Journal International 146 (2001) F1-F7. Piper, D. J. W., Shor, A. N. Ve Hughes Clarke, J. E. (1988): The 1929 Grand Banks eartquake, slump and turbidity current. Clifton, H. E. (Ed) Sedimentologic consequences of convilsive geologic events. Geological. Society of American Special papers, 229, Polat, Ç. ve Tuğrul, S. (1995). Quantitative comparison of the influxes of nutrients and organic carbon into the Sea of Marmara. Wat. Sci. Tech. 2: Polonia A., Gasperini L., Amorosi A., Bonatti E., Çağatay, N., Capotondi L., Cormier M.- H., Görür N., McHugh C., Seeber L., Holocene Slip Rate of the North Anatolian Fault beneath the Sea of Marmara. Earth and Planet. Sci.Letters, 227: October marmara-observatory 9/10

10 ESONET NoE Annex I Description of Work / APPENDIXES Polonia, A. Cormier, M.-H., Çağatay, N., G. Burtoluzi, E. Bonatti, N. Görür, et al. (2002). Exploring submarine earthquake geology in the Marmara Sea. EOS AGU Transactions, 83 (21), pp.229 and Prior, D. B., Suhayda, J. N., Lu, N. Z., Bornhold, B. D., Keller, G. H., Wiseman, W. J., Wright, L. D., Yang, Z-S.,1989. Storm wave reactivation of a submarine landslide. Nature 341: Reilinger R., N. Toksoz, S. McKlusky, A. Barka, 1999 Izmit, Turkey earthquake was no surprise, GSA Today, 10 (2000) 1-6. Seeber, L. Emre, O. Cormier, M.-H. Sorlien C.C., McHugh, C.M.G., Polonia, A. Ozer, N., Çağatay, N. and The team of the 2000 R/V Urania Cruise in the Marmara Sea (2004). Uplift and subsidence from oblique slip: the Ganos Marmara bend of the North Anatolian Transform, western Turkey.Tectonophysics, 391: Shiki, T., Kumon, F., Inouchi, Y., Kontani, Y., Sakamoto, T., Tateishi, M., Matsubara, H., Fukuyama, K. (2000): Sedimentary features of the seismo-turbidites, Lake Biwa, Japan. Sedimentary Geology 135, Siani, G., Paterne, M., Arnold, M., Bard, E., Metivier, B., Tisnerat, N., Bassinot, F., (2000): Radiocarbon reservoir ages in the Mediterranean Sea and Black Sea. Radiocarbon, 42, Straub, C. and Kahle, H. G.(1994): Actual crustal deformation in the Marmara Sea region. Abstract. Spring Meeting American Geophysical Union (AGU). EOS, Supplement, April 19, p Straub, C., Kahle, H.-G.,Schindler, C. (1997). GPS and geologic estimates of the tectonic activity in the Marmara region, NW Anatolia. J. Geophys. Res., 102, Şengör, A.M.C., The North Anatolian Transform Fault. : its age, offset and tectonic significance. J. Geol. Soc. London, 136: Şengör, A.M.C., Görür, N., Şaroğlu, F. (1985): Strike slip, faulting and related basin formation in zones of tectonic escape: Turkey as a case study, In Bıddle, K.T. ve Christie- Blick(eds.), Strike-slip faulting and basin formation, Society of Econ. Paleont. Min. Spec. Pub., 37. Şengör, A.M.C., Tüysüz, O., Imren, C., Sakinç, M., Eyidoğan, H., Görür, N., Le Pichon, X., Rangin, C. (2004). The North Anatolian Fault. A new look. Ann. Rev. Earth Planet. Sci. 33: Toksöz M. N., R.E. Reilinger, C.G. Doll, A.A. Barka, N. Yalcin, Izmit (Turkey) earthquake of 17 August 1999: first report, Seismological Research Letters 70 (1999) Ünlüata, Ü., Oğuz, T., Latif M.A., Özsoy, E. (1990). On the physical oceanography of the Turkish Straits. In. Pratt, L.J. (ed.), The Physical Oceanography of the Sea Straits. NATO/ASI Series, Kluwer, Dordrecht, pp Yalçıner, A.C., Alpar, B., Altınok, Y.Özbay, İ., F. Umamura, F. (2002). Tsunamis in the Sea of Marmara. Marine Geology, 190: October marmara-observatory 10/10