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The 1912 Earthquake
The 1912 Earthquake

The 9 August 1912 Mürefte earthquake (M>7) is one of the largest seismic events in the Balkan region in the 20th century. It caused significant damage in a wide area in NW Turkey and partly in Greece and Bulgaria. Today, our knowledge on this event is a key element to calculate accurately the dimensions of the approaching earthquake in the Marmara region.

The 9 August 1912 Mürefte earthquake occurred with an epicentre near the Mürefte village of the industrial city Tekirdağ and the size of the event is calculated as Ms 7.3 (Figure 1; Ambraseys and Finkel, 1987; Ambraseys and Jackson, 2000). The earthquake was accompanied with major surface faulting and co-seismic slip up to 5.5 m all along the onland section (Yaltırak and Alpar, 2002; Altınok et al., 2003; Altunel et al., 2004; Aksoy et al., 2010). The tremor caused also some considerable amount of land-sliding off the fault (Macovei, 1913; Mihailovic, 1927). The 9 August shock was followed on 13 September by a second large seismic shock (Ms 6.9) that occurred towards the west of the earlier shock.

 

Figure 1: The Ganos fault segment and its extension towards the Sea of Marmara and the Gulf of Saros. Roman numbers indicate MSK intensity of the second shock on 13 September 1912 (Aksoy et al., 2010). Inset isoseismals of the 9 August 1912 Mürefte earthquake (Ambraseys & Finkel, 1987)

The earthquake attracted interest of several scientists of that time and field investigations were carried out within a few days and weeks after the shock. The tremor was considered to be similar in size to the 28 December 1908 Messina- Italy earthquake (M 7.5) (Mihailovic 1918, 1923, 1927). Three key contemporaneous reports (i.e. Macovei, 1913; Mihailovic 1927; Sadi, 1912) provide ample descriptions of surface faulting and right-lateral offsets, landslides and detailed accounts of damage distribution. Observations are mainly localized in four regions; Mursallı, Ormanlı, Kirazlı and Saros. Additional information is available for Gaziköy, Güzelköy, and Gölcük areas. Surface faulting is evident at Gaziköy, Güzelköy, Mursallı, Gölcük and Saros, other localities experiencing landslides or lateral spreading. Photographs are available for some part of the fault and express typical strike-slip surface faulting morphology.

Figure 2: Surface ruptures of the 9 August 1912 Mürefte earthquake, nearby Mursallı Village. Photograph by Mihailovic (Ambraseys & Finkel, 1987).

The destruction and loss of life is described in many sources (Sadi, 1912; Macovei, 1912, 1913; Mihailovic, 1918, 1927, Agamennone, 1912, Mâmâcânyam, 19??). However estimations of the loss vary widely from one to another. The extensive study of Ambraseys & Finkel (1987) relay primarily on the observations of Mihailovic (1927). The damage was centred between Çanakkale (Dardanelles) and Tekirdağ, but also reached all the way to Istanbul, Edirne, Enez, Adapazarı, Ayvalık and Bursa (Ambraseys & Finkel, 1987; Mihailovic 1927). Heavy damage was recorded at Gaziköy, Hoşköy, Mürefte, Şarköy, Güzelköy, Mursallı, Yayaköy, Kavak, Gelibolu and Çanakkale. The maximum damage was localized between Tekirdağ and Mürefte which allowed to assigning a IX-X MSK maximum intensity near the Mürefte village (Figure 1).

The earthquake struck at 03:30 a.m. local time and affected an area containing 565,8000 people living in 122,400 houses (excluding Istanbul, Ambraseys & Finkel, 1987). The devastation of the shake killed 2800 and injured 7000 people. It totally destroyed 12600 houses, damaged 12100 beyond repair and caused serious damage to another 15,400 (Ambraseys & Finkel, 1987). The damage distribution is given in MSK scale in figure 1 and corresponds almost entirely to the 9 Aug. shock associated to a lesser degree to several fires which broke in the town and villages in the epicentral area.


Figure 3: Damage at Mürefte; minaret of a collapsed and burned mosque (a) and a view from Hoşköy showing the total destruction (b) caused by the 9 August shock. Photograph by Mihailovic.


 

Figure 4: Damage at Şarköy and villagers. Photograph by Sadi 1912.

 

 

Especially since the 1999 İzmit earthquake, the 1912 earthquake segment has been of major interest to today’s researchers. Prior to 1999, Rockwell et al., 2001 opened paleoseismic trenches on the western section of the Ganos fault and documented the presence of the 1912 rupture at this site. Further trenching studies have been performed on the eastern and central sections of the onland 1912 rupture (Aksoy, 2009; Meghraoui et al., submitted). The co-seismic displacement distribution has been documented in detail for the first time by Altunel et al., 2004. The rupture dimension of the 1912 earthquake has always been one of the major discussions on the event.  Several rupture length have been proposed in recent studies (Altınok et al., 2003a; Altunel et al., 2004; Armijo et al., 2005; Aksoy et al., 2010).

Onshore studies documented traces of tsunami events related to the 1912 tremor (Altınok., 2003b). Several scientific cruises performed high resolution bathymetric surveys and expeditions using ROV’s in the Sea of Marmara and also in the Saros Bay – Aegean Sea. Remarkable structures of active faulting and recent surface ruptures have been documented in both seas; the Sea of Marmara and Saros bay (Le Pichon, et al., 2003; Armijo et al., 2005; McHugh et al., 2006; McNeil et al., 2004; Ustaömer, et al., 2008; Gasperini et al., 2011).

In addition, over 70 historical seismograms have been collected for the 9 August 1912 Mürefte earthquake. Digitization and analysis are still underway and will shed light on the geophysical characteristics of the event. 

Today, the 1912 Mürefte earthquake is becoming one of the most extensively studied seismic events along the North Anatolian fault. The commemoration of the 100th year of the Mürefte earthquake in the PANAF meeting will give the occasion to exhibit recent findings about the 1912 earthquake and related Ganos fault segment.

REFERENCES:

Aksoy, M.E., 2009, Active Tectonics and Paleoseismology of the Ganos Fault Segment and Seismıc Characteristics of The 9 August 1912 Mürefte Earthquake of the North Anatolian Fault (Western Turkey): Istanbul, Istanbul Technical University.

Aksoy, M.E., Meghraoui, M., Vallee, M., and Cakir, Z., 2010, Rupture characteristics of the A.D. 1912 Murefte (Ganos) earthquake segment of the North Anatolian fault (western Turkey): Geology, v. 38, p. 991-994.

Altınok, Y., Alpar, B., and Yaltırak, C., 2003a, Şarköy - Mürefte 1912 Earthquake's Tsunami, extension of the associated faulting in the Marmara Sea, Turkey: Journal of Seismology, v. 7, p. 329-346.

Altınok, Y., Alpar, B., and Yaltırak, C., 2003b, Tsunami of Şarköy-Mürefte 1912 earthquake: Western Marmara, Turkey, in Yalçıner, A.C., Pelinovsky, E.N., Okal, E., and Synolakis, C.E., eds., Submarine Landslides and Tsunamis: Dordrecht, Kluwer Academic Publisher.

Altunel, E., Meghraoui, M., Akyüz, H.S., and Dikbaş, A., 2004, Characteristics of the 1912 co-seismic rupture along the North Anatolian Fault Zone (Turkey): implications for the expected Marmara earthquake: Terra Nova, v. 16, p. 198-204.

Ambraseys, N.N., and Finkel, C.F., 1987, The Saros-Marmara earthquake of 9 August 1912: Earthquake engineering & structural dynamics, v. 15, p. 189-211.

Ambraseys, N.N., and Jackson, J.A., 2000, Seismicity of the Sea of Marmara (Turkey) since 1500: Geophysical Journal International, v. 141, p. F1-F6.

Armijo, R., Pondard, N., Meyer, B., Uçarkus, G., Lepinay, B.M.d., Malavieille, J., Dominguez, S., Gustcher, M.-A., Schmidt, S., Beck, C., Çagatay, N., Çakir, Z., Imren, C., Eriş, K., Natalin, B., Özalaybey, S., Tolun, L., Lefevre, I., Seeber, L., Gasperini, L., Rangin, C., Emre, O., and Sarikavak, K., 2005, Submarine fault scarps in the Sea of Marmara pull-apart (North Anatolian Fault): Implications for seismic hazard in Istanbul: Geochemistry Geophysics Geosystems, v. 6, p. Q06009.

Gasperini, L., Polonia, A., Çağatay, M.N., Bortoluzzi, G., and Ferrante, V., 2011, Geological slip rates along the North Anatolian Fault in the Marmara region: Tectonics, v. 30, TC6001, p. 1-14.

Le Pichon, X., Chamot-Rooke, C., Rangin, N., and Şengör, A.M.C., 2003, The North Anatolian fault in the Sea of Marmara: J. Geophys. Res., v. 108, p. 2179.

Macovei, G., 1913, Aspura Cutremurului de Pamant dela Mare de Marmara dela 9 August 1912: Academia Romana, Publicatiunile Adamachi V., v. 33, p. 260-273.

McNeill, L.C., Mille, A., Minshull, T.A., Bull, J.M., Kenyon, N.H., and Ivanov, M., 2004, Extension of the North Anatolian Fault into the North Aegean Trough: Evidence for transtension, strain partitioning, and analogues for Sea of Marmara basin models: Tectonics, v. 23, p. 12.

Meghraoui M., Aksoy, Akyüz, S., M.E., Ferry, M., Dikbaş. A., Altunel., E., (submitted), Paleoseismology of the North Anatolian Fault at Güzelköy  (Ganos segment, Turkey): Size and recurrence time of earthquake ruptures west of the Sea of Marmara, G3 (in review)

Mihailovic, J., 1918, Resultats des études sur le tremblement de terre d’aout et de septembre 1912 sur la mer de Marmara, Volume 166: Paris, C.R. Acad. Scien. Paris, p. 784 - 787.

Mihailovic, J., 1923, Le  mecanisme  des  mouvements  sismiques  dans la  mer  de  Marmara: Bulletin de  l'Academie royale des Sciences de Serbie, Belgrad, v. 108, p. 54-63.

Mihailovic, J., 1927, Trusne katastrofe na Mramornome moru sa narocitim pogledom na opstu seizmicnost Mramornoga mora i njegovih obala, Srpska kraljevska akademija, posebna izdanja, knj. LXV - Prirodnjacki i matematicki spisi, knj. 16, 303 str., 78 sl., 46 skica, 6 dijagrama, 1 karta, Volume 65: Belgrade, p. 1-303.

Rockwell, T.K., Barka, A., Dawson, T., Akyüz, S., and Thorup, K., 2001, Paleoseismology of the Gazikoy-Saros segment of the North Anatolia fault, northwestern Turkey: Comparison of the historical and paleoseismic records, implications of regional seismic hazard, and models of earthquake recurrence: Journal of Seismology, v. 5, p. 433-448.

Sadi, D.Y., 1912, Marmara Havzasının 26-27 Temmuz Hareket-i Arzı 15 Eylül 1328: Resimli Kitap Matbaası, İstanbul, p. 45.

Ustaömer, T., Gökaşan, E., Tur, H., Görüm, T., Batuk, F., Kalafat, D., Alp, H., Ecevitoğlu, B., and Birkan, H., 2008, Faulting, mass-wasting and deposition in an active dextral shear zone, the Gulf of Saros and the NE Aegean Sea, NW Turkey: Geo-Marine Letters, v. 28, p. 171-193.

Yaltırak, C., and Alpar, B., 2002, Kinematics and evolution of the northern branch of the North Anatolian Fault (Ganos Fault) between the Sea of Marmara and the Gulf of Saros: Marine Geology, v. 190, no. 1-2, p. 351-366.