Morphological Features of Major Submarine Landslides of Marmara Sea Using Multibeam Data

Gazioğlu, Cem; Yücel, Zeki; Doğan, Emine

doi:10.2112/03-0060.1

Cited by 33 publications

(26 citation statements)

References 26 publications

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“…These features indicate brittle behavior of the seafl oor sediments. The morphologic appearance of such slump mass surfaces is similar to the crescent-shaped bedforms described herein (e.g., Gardner et al, 1999;Gazioglu et al, 2005).…”

Section: Formation Of Large Crescent-shaped Bedformssupporting

confidence: 67%

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

et al. 2010

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Crescent-shaped bedforms with wavelengths from 20 to 80 m, amplitudes to 2.5 m, and concave down-canyon crests occur in the axial channel of Monterey Canyon (offshore California, USA) in water depths from 11 to more than 350 m. The existence of these features may be an important new clue as to how sediment moves through submarine canyons. Three complementary studies were initiated in 2007 to understand the origin and evolution of these bedforms. (1) Vibracoring. Three transects of closely spaced remotely operated vehicle-collected vibracores were obtained across these bedforms. The seafl oor underneath these features is composed of gravity-fl ow deposits. (2) Acoustic array. Three boulder-sized concrete monuments containing acoustic beacons were buried just below the surface of the canyon fl oor in ~290 m water depth and their locations were redetermined on 17 subsequent occasions. Although the beacons became more deeply buried >0.6 m below the seafl oor, they still could be tracked acoustically. Over a 26-month period the position of 1 or more of the beacons moved down-canyon during at least 6 discrete transport events for a total displacement of 994-1676 m. The movement and burial of the monuments suggest that the seabed was mobilized to >1 m depth during gravity-fl ow events. (3) Autonomous underwater vehicle (AUV) repeat mapping. AUV-acquired high-resolution multibeam mapping , and CHIRP (compressed highintensity radar pulse) subbottom profi ling surveys of the seafl oor in the active channel were repeated four times in the fi rst half of 2007. In addition, the movement of large instrument frames deployed in 2001-2003 within the axis of Monterey Canyon in the area now known to be associated with the crescent-shaped bedforms is documented.The fate of the frames has helped elucidate the frequency, transport potential, and processes occurring within the axis of Monterey Canyon associated with these bedforms. The crescent-shaped bedforms appear to be produced during brief gravity-fl ow events that occur multiple times each year, commonly coincident with times of large signifi cant wave heights. Whether the bedforms are generated by erosion associated with cyclic steps in turbidity fl ows or internal deformation associated with slumping during gravity-fl ow events remains unclear.

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Section: Formation Of Large Crescent-shaped Bedformssupporting

confidence: 67%

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

et al. 2010

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“… Fault model showing the segmentation and right and left step‐over of the NAF, in eastern and western parts of the Sea of Marmara, respectively. The morphological map of the Sea bottom is prepared by Gazioğlu et al (2002). The abbreviations are as follows: GF, Ganos fault; NAF, North Anatolian fault; IF, Izmit fault; PI, Princes' Island fault; HSF, heterogenious stress field region.…”

Section: Discussionmentioning

confidence: 99%

Moment tensor inversion of recent small to moderate sized earthquakes: implications for seismic hazard and active tectonics beneath the Sea of Marmara

Pınar

Kuge²,

Honkura³

2003

Geophysical Journal International

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SUMMARY We retrieve the moment tensors of 64 small to moderate sized events that occurred mostly beneath the Sea of Marmara using near‐field data recorded at strong‐motion and broad‐band seismic stations. The near‐field displacement records are inverted to their sources utilizing Kuge's method where the best fit between the synthetic and observed seismograms is achieved through searching a centroid moment tensor (CMT) point in a grid scheme. We also analyse the stress fields acting in the eastern and western parts of the Sea of Marmara by inverting the P‐ and T‐axes of the focal mechanisms obtained. Significant biases in the stress tensors are obtained. The nearly horizontal maximum compressive axis σ1 in the western part is rotated 16° counter‐clockwise compared with σ1 in the eastern part. The σ2‐axis is close to vertical (shear tectonic regime) in the east and the plunge of σ2‐axis in the west is 36° (transpressive tectonic regime). Changes in the σ3‐axis are also observed, that is, it is close to horizontal in the east and dips 49° in the west. The spatial distribution of the focal mechanisms suggests that the stress field in the eastern part of the Sea of Marmara is homogenous compared with the western part, and we identify five distinct subsidiary faults. (1) a WNW–ESE‐striking, right‐lateral strike‐slip fault located a few kilometres SW of the Princes' Islands, (2) a WSW–ENE‐striking, right‐lateral strike‐slip fault named the Yalova–Hersek fault, (3) an E–W‐striking normal fault located onshore between Yalova and Çinarcik, (4) a NNW–SSE‐striking, left‐lateral strike‐slip fault located NE of the Princes' Islands and (5) minor thrust faults located in the Central High of the Sea of Marmara and in the vicinity of the Hersek Delta. The locations and the sense of motion of these five shear zones are explained by a very simple deformation model that requires a major E–W‐striking right‐lateral strike‐slip fault, namely the North Anatolian Fault (NAF), within a stress field with maximum compression, σ1, in the NW–SE direction and minimum compression, σ3, in the NE–SW direction, as was derived from the stress tensor analysis. The mechanisms of the events occurring in the western part of the Sea of Marmara reveal a heterogeneous stress field that may result from the change in the strike of NAF from nearly E–W to WSW. The western Marmara Sea events are consistent with a deformation model that requires a major right‐lateral strike‐slip fault striking ENE–WSW with a stress field with maximum principal stress axis, σ1, oriented ESE and minimum principal stress axis, σ3, oriented NNE.

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“…The 1999 earthquake triggered rapid mass movements and gas/fl uid release and/or remobilization in the Gulf of Izmit (Kuşçu et al, 2005;Cormier et al, 2006). Catastrophic slope failure also occurs elsewhere in Marmara (e.g., in east Çınarcık and west Tekirdağ basins; Gazioğlu et al, 2005) (Fig. 1B), particularly in areas where subsidence and uplift are most rapid (e.g., Seeber et al, 2004).…”

Section: Tectonics and Stratigraphy In Marmaramentioning

confidence: 99%

Evidence for widespread creep on the flanks of the Sea of Marmara transform basin from marine geophysical data

Shillington

Seeber

Sorlien

et al. 2012

Geology

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aboard the R/V K. Piri Reis, which is operated by Dokuz Eylül University (Izmir, Turkey) (Fig. 1A). MCS data were acquired on a 450 m streamer in 2008, and on a 700 m or 1500 m streamer in 2010. The common midpoint (CMP) spacing was 3.125 m, streamer depth was 3-4 m, and ABSTRACT"Wave" fi elds have long been recognized in marine sediments on the fl anks of basins and oceans in both tectonically active and inactive environments. The origin of "waves" (hereafter called undulations) is controversial; competing models ascribe them to depositional processes, gravity-driven downslope creep or collapse, and/or tectonic shortening. Here we analyze pervasive undulation fi elds identifi ed in swath bathymetry and new high-resolution multichannel seismic (MCS) refl ection data from the Sea of Marmara, Turkey. Although they exhibit some of the classical features of sediment waves, the following distinctive characteristics exclude a purely depositional origin: (1) parallelism between the crests of the undulations and bathymetric contours over a wide range of orientations, (2) steep fl anks of the undulations (up to ~40°), and (3) increases in undulations amplitude with depth. We argue that the undulations are folds formed by gravity-driven downslope creep that have been augmented by depositional processes. These creep folds develop over long time periods (≥0.5 m.y.) and stand in contrast to geologically instantaneous collapse. Stratigraphic growth on the upslope limbs indicates that deposition contributes to the formation and upslope migration of the folds. The temporal and spatial evolution of the creep folds is clearly related to rapid tilting in this tectonically active transform basin.on June 2, 2015 geology.gsapubs.org Downloaded from (TUBITAK)-BİDEB supported a six-month research visit for Kurt to LDEO and the University of Missouri. We thank the captains and crew of the R/V K. Piri Reis, who made the acquisition of these data possible despite challenging conditions. We thank Hydroscience Technologies Inc. for supporting the seismic systems of R/V K. Piri Reis, Landmark for ProMAX software, and Seismic

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Morphological Features of Major Submarine Landslides of Marmara Sea Using Multibeam Data

Cited by 33 publications

References 26 publications

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

Origins of large crescent-shaped bedforms within the axial channel of Monterey Canyon, offshore California

Moment tensor inversion of recent small to moderate sized earthquakes: implications for seismic hazard and active tectonics beneath the Sea of Marmara

Evidence for widespread creep on the flanks of the Sea of Marmara transform basin from marine geophysical data

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