Deformation of Central Anatolia: GPS implications

Aktuğ, Bahadır; Parmaksiz, Erdem; Kurt, Mustafa; Lenk, Onur; Kılıçoǧlu, Ali; Gürdal, Mehmet A.; Özdemir, Soner Mehmet

doi:10.1016/j.jog.2012.05.008

Cited by 83 publications

(75 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Earthquake moment tensors show significant number of earthquakes within Anatolia (Figure b), several with normal faulting mechanisms, implying that there is ongoing internal deformation within Anatolia. Aktuğ et al [] also found significant ongoing deformation within Anatolia from detailed analysis of GNSS velocities in central Anatolia, which were more consistent with east‐west elastic elongation rather than a rigid‐body rotation [ Reilinger et al , ; McClusky et al , ] or simple transport [ Reilinger et al , ].…”

Section: Discussionmentioning

confidence: 95%

Interseismic strain accumulation across the central North Anatolian Fault from iteratively unwrapped InSAR measurements

et al. 2016

View full text Add to dashboard Cite

The North Anatolian Fault (NAF) is a major tectonic feature in the Middle East and is the most active fault in Turkey. The central portion of the NAF is a region of Global Navigation Satellite Systems (GNSS) scarcity. Previous studies of interseismic deformation have focused on the aseismic creep near the town of Ismetpasa using radar data acquired in a single line‐of‐sight direction, requiring several modeling assumptions. We have measured interseismic deformation across the NAF using both ascending and descending data from the Envisat satellite mission acquired between 2003 and 2010. Rather than rejecting incorrectly unwrapped areas in the interferograms, we develop a new iterative unwrapping procedure for small baseline interferometric synthetic aperture radar (InSAR) processing that expands the spatial coverage. Our method corrects unwrapping errors iteratively and increases the robustness of the unwrapping procedure. We remove long wavelength trends from the InSAR data using GNSS observations and deconvolve the InSAR velocities into fault‐parallel motion. Profiles of fault‐parallel velocity reveal a systematic eastward decrease in fault slip rate from 30 mm/yr (25–34, 95% confidence interval (CI)) to 21 mm/yr (14–27, 95% CI) over a distance of ∼200 km. Direct offset measurements across the fault reveal fault creep along a ∼130 km section of the central NAF, with an average creep rate of 8 ± 2 mm/yr and a maximum creep rate of 14 ± 2 mm/yr located ∼30 km east of Ismetpasa. As fault creep is releasing only 30–40% of the long‐term strain in the shallow crust, the fault is still capable of producing large, damaging earthquakes in this region.

show abstract

Section: Discussionmentioning

confidence: 95%

Interseismic strain accumulation across the central North Anatolian Fault from iteratively unwrapped InSAR measurements

et al. 2016

View full text Add to dashboard Cite

show abstract

“…These are considerably fewer than the 872 velocities used by Özeren and Holt [], but that data set contained many sites reported by two or more publications, and many sites that we have excluded by the criteria of number and duration of occupations. We therefore expect that the data set we use, in addition to having more information in Anatolia [ Aktuğ et al , , ; Ozener et al , ; Tatar et al , ; Yavaşoğlu et al , ], is appreciably less influenced by measurement error. The mean spacing between sites is about 50 km, though sites within the Aegean Sea are separated by up to 100 km.…”

Section: Gps Observationsmentioning

confidence: 99%

“…Although the large‐scale motions of Anatolia and the Aegean relative to Eurasia can be described approximately by a rigid‐body rotation with a pole near the Nile delta [ Le Pichon and Kreemer , ; Reilinger et al , ], active faults pervade the region and GPS velocities increase systematically by 20 mm/yr from east to west [e.g., Aktuğ et al , , ; Floyd et al , ; Goldsworthy and Jackson , , ; Goldsworthy et al , ; Jackson , ; Jackson and McKenzie , ; Reilinger et al , ; Şaroglu et al , ; Shaw and Jackson , ; Taymaz et al , ] (see Figures , and b). This deformation results in widespread large shallow earthquakes (Figure b) whose focal mechanisms vary from thrust and reverse faulting along the western and southern margins of the region to normal faulting throughout mainland Greece and western Turkey, to normal‐plus‐strike‐slip faulting in the northern Aegean, and to strike‐slip faulting on the north and southeastern margins of Anatolia.…”

Section: Introductionmentioning

confidence: 99%

Constraints from GPS measurements on the dynamics of deformation in Anatolia and the Aegean

2016

View full text Add to dashboard Cite

We estimate the strength of the lithosphere in Anatolia and the Aegean, and the boundary forces acting upon it, using a dynamical model that treats the lithosphere as a thin fluid sheet deforming in response to variations in gravitational potential energy. This model has one free material parameter, the power law exponent, n, of the vertically averaged rheology of the lithosphere, and two parameters that specify the forces per unit length applied to its edges. Solutions to this model that best fit the velocities of 346 reliable GPS sites require an effective viscosity of the lithosphere of 1022 to 1021 Pa s at strain rates of 10 to 100 nanostrain per year. The best‐fitting force at the Arabia‐Anatolia boundary is consistent with the lithostatic pressure due to the high topography there, and the force at the Nubia‐Aegean boundary is consistent with the contrast in lithostatic pressure across that boundary. No additional force, from “slab rollback” or basal tractions due to convection in the mantle, is required to explain the observations. These results are supported by scaling relations derived from approximate analytical solutions. The inverse relationship between the viscosity of the lithosphere and deviatoric stress produces strong slowly deforming regions in the Southern Aegean and Central Anatolia whose motions resemble those of microplates. The distribution of geodetic strain rates within the region, and the partitioning between normal and strike‐slip faulting, are explained by the interplay between boundary conditions, internal variations in gravitational potential energy, and the power law rheology of the lithosphere.

show abstract

“…The regional motion between the two plates has been investigated by several researches and is thought to range from 22 to 28 mm/year (Aktuğ et al, 2013;Meade et al, 2002;Reilinger et al, 2006); it has caused a series of earthquakes along NAF. The regional motion between the two plates has been investigated by several researches and is thought to range from 22 to 28 mm/year (Aktuğ et al, 2013;Meade et al, 2002;Reilinger et al, 2006); it has caused a series of earthquakes along NAF.…”

Section: Introductionmentioning

confidence: 99%

Seafloor Geodesy Revealed Partial Creep of the North Anatolian Fault Submerged in the Sea of Marmara

Yamamoto

Kido

Ohta

et al. 2019

Geophysical Research Letters

View full text Add to dashboard Cite

In this study, the creep rate across the North Anatolian Fault was directly measured in the western Sea of Marmara using the seafloor acoustic ranging technique; the data reveal coupling conditions on the fault interface and stress accumulation with implications for regional seismic risk evaluation. Continuous measurements over a period of 3.5 years at a site in the Western High clearly indicate right‐lateral displacement at a rate of 10.7 ± 4.7 mm/year (95% confidence level); approximately half of the regional block motion at this location is released by this steady motion. A simple model of three elastic layers—a partially creeping sedimentary layer (8 km) at the top with the observed rate, a locked (3 km) and fully creeping layer in the middle, and a bottom layer—assumed from seismicity, reasonably explains onshore Global Navigation Satellite System data for the surrounding region.

show abstract

Deformation of Central Anatolia: GPS implications

Cited by 83 publications

References 56 publications

Interseismic strain accumulation across the central North Anatolian Fault from iteratively unwrapped InSAR measurements

Interseismic strain accumulation across the central North Anatolian Fault from iteratively unwrapped InSAR measurements

Constraints from GPS measurements on the dynamics of deformation in Anatolia and the Aegean

Seafloor Geodesy Revealed Partial Creep of the North Anatolian Fault Submerged in the Sea of Marmara

Contact Info

Product

Resources

About