102 research outputs found
Gas and seismicity within the Istanbul seismic gap
Understanding micro-seismicity is a critical question for earthquake hazard
assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the
seismicity along the submerged section of North Anatolian Fault within the Sea
of Marmara (comprising the âIstanbul seismic gapâ) has been extensively
studied in order to infer its mechanical behaviour (creeping vs locked). So
far, the seismicity has been interpreted only in terms of being tectonic-
driven, although the Main Marmara Fault (MMF) is known to strike across
multiple hydrocarbon gas sources. Here, we show that a large number of the
aftershocks that followed the M 5.1 earthquake of July, 25th 2011 in the
western Sea of Marmara, occurred within a zone of gas overpressuring in the
1.5â5âkm depth range, from where pressurized gas is expected to migrate along
the MMF, up to the surface sediment layers. Hence, gas-related processes
should also be considered for a complete interpretation of the micro-
seismicity (~Mâ<â3) within the Istanbul offshore domain
Tajik Basin: A composite record of sedimentary basin evolution in response to tectonics in the Pamir
Investigation of a >6âkmâthick succession of Cretaceous to Cenozoic sedimentary rocks in the Tajik Basin reveals that this depocentre consists of three stacked basin systems that are interpreted to reflect different mechanisms of subsidence associated with tectonics in the Pamir Mountains: a Lower to midâCretaceous succession, an Upper CretaceousâLower Eocene succession and an EoceneâNeogene succession. The Lower to midâCretaceous succession consists of fluvial deposits that were primarily derived from the Triassic KarakulâMazar subductionâaccretion complex in the northern Pamir. This succession is characterized by a convexâup (accelerating) subsidence curve, thickens towards the Pamir and is interpreted as a retroarc foreland basin system associated with northward subduction of Tethyan oceanic lithosphere. The Upper Cretaceous to early Eocene succession consists of fineâgrained, marginal marine and sabkha deposits. The succession is characterized by a concaveâup subsidence curve. Regionally extensive limestone beds in the succession are consistent with late stage thermal relaxation and relative seaâlevel rise following lithospheric extension, potentially in response to Tethyan slab rollback/foundering. The Upper Cretaceousâearly Eocene succession is capped by a middle Eocene to early Oligocene (ca. 50â30 Ma) disconformity, which is interpreted to record the passage of a flexural forebulge. The disconformity is represented by a depositional hiatus, which is 10â30 Myr younger than estimates for the initiation of IndiaâAsia collision and overlaps in age with the start of prograde metamorphism recorded in the Pamir gneiss domes. Overlying the disconformity, a >4âkmâthick upper EoceneâNeogene succession displays a classic, coarsening upward unroofing sequence characterized by accelerating subsidence, which is interpreted as a retroâforeland basin associated with crustal thickening of the Pamir during IndiaâAsia collision. Thus, the Tajik Basin provides an example of a longâlived composite basin in a retrowedge position that displays a sensitivity to plate margin processes. Subsidence, sediment accumulation and basinâforming mechanisms are influenced by subduction dynamics, including periods of slabâshallowing and retreat
Kinematics of the East Anatolian Fault Zone between Turkoglu (Kahramanmaras) and Celikhan (Adiyaman), eastern Turkey
Investigating P- and S-wave velocity structure beneath the Marmara region (Turkey) and the surrounding area from local earthquake tomography
26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15â20 July 2017
This work was produced as part of the activities of FAPESP Research,\ud
Disseminations and Innovation Center for Neuromathematics (grant\ud
2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud
FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud
supported by a CNPq fellowship (grant 306251/2014-0)
Tectonic evolution of Tethyan tectonic field, formation of Northern Margin basin and explorative perspective of natural gas in Tarim Basin
The Palaeo-Tethyan suture: A line of demarcation between two fundamentally different architectural styles in the structure of Asia
Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea
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