Present-day crustal motion around the Pamir Plateau from GPS measurements

Zhou, Yun; He, Jun; Oimahmadov, Ilhomjon; Gadoev, Mustafo; Pan, Zaifa; Wang, Weimin; Abdulov, Sherzod; Rajabov, Negmat

doi:10.1016/j.gr.2016.03.011

Cited by 33 publications

(45 citation statements)

References 64 publications

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“…The GPS velocities (Figures and and Table S1) show ongoing convergence between India and Eurasia, with the steepest velocity gradients localized near the northern margin of the Pamir, consistent with other GPS results (Ischuk et al, ; Reigber et al, ; Zhou et al, ; Zubovich et al, ). The shortening rate on and adjacent to the Main Pamir Fault system is 18–22 mm/year (65–80% of the total India‐Eurasia relative rate of 28 ± 4 mm/year, measured from Karachi; Mohadjer et al, ), increasing along strike eastward (Figures and ).…”

Section: Kinematic Resultssupporting

confidence: 88%

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

Perry

Kakar

Ischuk

et al. 2019

Geophysical Research Letters

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Geodetically derived velocities from Central Asia show that Northern Afghanistan, the Tajik Pamir, and northwestern Pakistan all move northward with comparable large velocities toward Eurasia. Steep velocity gradients, hence high strain rates, occur only across the Main Pamir Fault zone and with lesser magnitude between the northernmost Hindu Kush and the south and southeast margins of the Tajik Depression. Localized shortening is not apparent on any active India‐Hindu Kush crustal boundary; hence, crustal convergence between India and Eurasia in Central Asia is absorbed primarily on the northern and western margins of the Pamir. This concentrated strain on the Pamir margins is consistent with one, geometrically complex, interface between subducting Asian lithosphere and the Pamir. That interface might curve westward such that the Hindu Kush seismic zone is a continuation of the Pamir seismic zone, or alternatively, Hindu Kush earthquakes might occur in convectively unstable mantle lithosphere mechanically detached from surface faults.

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Section: Kinematic Resultssupporting

confidence: 88%

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

Perry

Kakar

Ischuk

et al. 2019

Geophysical Research Letters

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“…The high recent shortening rates across the Pamir thrust system cause frequent thrust earthquakes with the 2008 M w 6.7 Nura (Sippl et al, ; Teshebaeva et al, ) and 2016 M w 6.4 Sary Tash (USGS, ) earthquakes being the most recent. In the Pamir interior, thrusting has ceased and the displacement field is composed of bulk northward movement combined with E‐W extension (Ischuk et al, ; Zhou et al, ). The latter is driven by westward gravitational collapse of thickened Pamir plateau crust into the Tajik basin, where it causes approximately E‐W shortening of the sedimentary strata of the Tajik basin above an evaporitic décollement (Nikolaev, ; Schurr et al, ; Stübner et al, ) (Figure c).…”

Section: Tectonic Settingmentioning

confidence: 99%

The 2015 M_w7.2 Sarez Strike‐Slip Earthquake in the Pamir Interior: Response to the Underthrusting of India's Western Promontory

et al. 2017

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The Pamir orogen, Central Asia, is the result of the ongoing northward advance of the Indian continent causing shortening inside Asia. Geodetic and seismic data place the most intense deformation along the northern rim of the Pamir, but the recent 7 December 2015, Mw7.2 Sarez earthquake occurred in the Pamir's interior. We present a distributed slip model of this earthquake using coseismic geodetic data and postseismic field observations. The earthquake ruptured an ∼80 km long, subvertical, sinistral fault consisting of three right‐stepping segments from the surface to ∼30 km depth with a maximum slip of three meters in the upper 10 km of the crust. The coseismic slip model agrees well with en échelon secondary surface breaks that are partly influenced by liquefaction‐induced mass movements. These structures reveal up to 2 m of sinistral offset along the northern, low‐offset segment of modeled rupture. The 2015 event initiated close to the presumed epicenter of the 1911 Mw∼7.3 Lake Sarez earthquake, which had a similar strike‐slip mechanism. These earthquakes highlight the importance of NE trending sinistral faults in the active tectonics of the Pamir. Strike‐slip deformation accommodates shear between the rapidly northward moving eastern Pamir and the Tajik basin in the west and is part of the westward (lateral) extrusion of thickened Pamir plateau crust into the Tajik basin. The Sarez‐Karakul fault system and the two large Sarez earthquakes likely are crustal expressions of the underthrusting of the northwestern leading edge of the Indian mantle lithosphere beneath the Pamir.

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“…Extensional fault systems are highlighted in yellow area. (b) Major Cenozoic structures, GPS velocities (Zhou et al, 2016), earthquakes, and major focal mechanisms associated with major active structures (U.S. Geological Survey seismic catalog, http://earthquake.usgs.gov/earthquakes/) in the northeastern Pamir and adjacent areas (location shown by white corners in Figure 1a). (c) GPS velocities (Zhou et al, 2016) 2015; Schurr et al, 2014;Sippl et al, 2013;Sobel et al, 2011Sobel et al, , 2013Thiede et al, 2013;Zubovich et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…(b) Major Cenozoic structures, GPS velocities (Zhou et al, 2016), earthquakes, and major focal mechanisms associated with major active structures (U.S. Geological Survey seismic catalog, http://earthquake.usgs.gov/earthquakes/) in the northeastern Pamir and adjacent areas (location shown by white corners in Figure 1a). (c) GPS velocities (Zhou et al, 2016) 2015; Schurr et al, 2014;Sippl et al, 2013;Sobel et al, 2011Sobel et al, , 2013Thiede et al, 2013;Zubovich et al, 2010). This tectonic deformation is proposed to result from radial thrusting along the orogen margin (e.g., Cowgill, 2010;Pan et al, 2018;Strecker et al, 1995), gravitational collapse and westward extrusion of orogenic material (Jay et al, 2017;Kufner et al, 2018;Schurr et al, 2014;Thiede et al, 2013), oroclinal bending of the entire Pamir-Western Himalayan region (Yin et al, 2001), clockwise rotation of the rigid Tarim basin , and/o thermal and density effects related to a lithospheric tear fault Thiede et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Cumulative and Coseismic (During the 2016 M_w6.6 Aketao Earthquake) Deformation of the Dextral‐Slip Muji Fault, Northeastern Pamir Orogen

Schoenbohm

Chen

et al. 2019

Tectonics

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Located at the northwestern syntaxis of the India‐Asia convergence zone, the Pamir orogen is characterized by complicated and strong active deformation. Constraining the detailed geometry and kinematics of major active structures is important both for understanding modern tectonic processes and for evaluating potential seismic hazards of the region. Our work focuses on the Muji Fault in the northeastern Pamir. Based on cumulative deformation recorded by landforms and coseismic deformation during the 2016 Mw 6.6 Aketao earthquake, we determine the spatial extent, slip motion, fault‐plane geometry, and slip rate of the fault, on the basis of which we clarify its role in the modern tectonics of the Pamir and investigate its seismic behavior and associated seismic hazards. Our study indicates that (i) the Muji Fault, along with the Kongur Extensional System to its south, acts as a boundary fault that accommodates a relative divergence rate of 1.4–2.0°/Ma between the central‐western and eastern Pamir; (ii) geometric discontinuities along the fault exerted an important control on seismic rupture termination and slip gap formation during the Aketao earthquake; and (iii) the cumulative surface‐faulting deformation cannot be formed coseismically by repetitions of the Aketao earthquake, implying significant aseismic (postseismic and/or interseismic) creeping or possibly larger (approximately Mw 7.2), surface‐faulting earthquakes. Our study highlights the usefulness of correlating cumulative and coseismic deformation patterns in active tectonic investigations and regional seismic hazard evaluations.

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Present-day crustal motion around the Pamir Plateau from GPS measurements

Cited by 33 publications

References 64 publications

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

The 2015 M_w7.2 Sarez Strike‐Slip Earthquake in the Pamir Interior: Response to the Underthrusting of India's Western Promontory

Cumulative and Coseismic (During the 2016 M_w6.6 Aketao Earthquake) Deformation of the Dextral‐Slip Muji Fault, Northeastern Pamir Orogen

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Present-day crustal motion around the Pamir Plateau from GPS measurements

Cited by 33 publications

References 64 publications

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

Little Geodetic Evidence for Localized Indian Subduction in the Pamir‐Hindu Kush of Central Asia

The 2015 Mw7.2 Sarez Strike‐Slip Earthquake in the Pamir Interior: Response to the Underthrusting of India's Western Promontory

Cumulative and Coseismic (During the 2016 Mw6.6 Aketao Earthquake) Deformation of the Dextral‐Slip Muji Fault, Northeastern Pamir Orogen

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The 2015 M_w7.2 Sarez Strike‐Slip Earthquake in the Pamir Interior: Response to the Underthrusting of India's Western Promontory

Cumulative and Coseismic (During the 2016 M_w6.6 Aketao Earthquake) Deformation of the Dextral‐Slip Muji Fault, Northeastern Pamir Orogen