Seismotectonic characteristics of the northern flank and axial part of the Tajik Depression (the Garm Geodynamic Research Area)

Lukk, A. A.; Leonova, V. G.; Шевченко, В. И.

doi:10.1134/s1069351308120021

Cited by 11 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…During our observation period, the seismogenic interface likely associated with the Vakhsh thrust hosted the largest crustal earthquakes. Thus, we propose that it accommodates most of the today's northwesterly motion of the Pamir, both in shortening and dextral shear (Lukk et al, , ). The events with subhorizontal fault planes in the center of the Peter I. range could then indicate sliding along a basal décollement either at the base of the sediments or in the basement rocks (e.g., Hamburger et al, ; Lukk et al, ).…”

Section: Interpretation and Discussionmentioning

confidence: 91%

Seismotectonics of the Tajik Basin and Surrounding Mountain Ranges

et al. 2018

View full text Add to dashboard Cite

Seismologic and geologic fault-slip data characterize the active deformation of the intramontane Tajik basin and its margins, the Tian Shan, Pamir, and Hindu Kush at the northwestern tip of the India-Asia collision zone. Within this complexly deforming region, the Tajik basin lithosphere forms the backstop for the north-dipping Indian-slab subduction beneath the Hindu Kush but itself delaminates and retreats west and northward beneath the Pamir. Herein, we link crustal deformation to these lithosphere-scale processes, using data from recently deployed seismic networks and geologic observations. Transpressive strike-slip deformation dominates the bounding fault zones along the basin's northern and eastern margins. Seismicity is most intense in the Garm region/Peter I. range of the northeastern basin, where these bounding faults converge and gain a dominant thrust component. Within the basin, seismically and geologically derived P axes align with the~W-trending GPS velocity vectors. Seismicity is concentrated in and at the base of a southward deepening, ∼9-15-km-thick wedge. Seismic deformation at the basin's southern margin occurs beneath the Afghan platform, where deep crustal earthquakes likely trace the western end of the Hindu Kush subduction zone. Roughly NNE-striking sinistral strike-slip events outline the Hindu Kush-Pamir transfer system, a zone of distributed shear in the crust overlying the transition of the two oppositely dipping slabs at subcrustal depths. Our observations suggest that crustal deformation in the Pamir and Hindu Kush links with lithosphere-scale processes, whereas deformation in the basin is controlled by the westward gravitational collapse of the Pamir and the resultant basin inversion.

show abstract

Section: Interpretation and Discussionmentioning

confidence: 91%

Seismotectonics of the Tajik Basin and Surrounding Mountain Ranges

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Pamir Thrust (MPT) further east (Hamburger et al 1992;Strecker et al 2003;Lukk et al 2008;Evans et al 2009;Lou et al 2009;Yuan et al 2013). The region is thus marked by several shallow to intermediate zones of high seismic activity along these fault systems, which are reflected by a high peak ground acceleration (PGA) of > 3.2 to > 4.8 m/s 2 for a return period of 475 years, where 0.8 m/s 2 suffices to trigger landslides (Hamburger et al 1992;Lukk et al 1995;Lou et al 2009;Fan et al 2019) (Earthquake Model Central Asia (http://www.emca-gem.org/), accessed 25 November 2020).…”

Section: Original Papermentioning

confidence: 99%

Active landslides in the Rogun Catchment, Tajikistan, and their river damming hazard potential

Jones

Manconi

Strom³

2021

Landslides

View full text Add to dashboard Cite

The region of Tajikistan where the Rogun Hydropower Project is currently under construction has experienced large and catastrophic slope failures in the past, often triggered by earthquakes. Co-seismic slope failures are thus common and pose a high hazard potential; however, to date, no specific analysis of slope activity in this area has been presented in international journals. Here, we present an inventory of active landslides identified through satellite imagery analysis and in particular by exploiting space-borne differential radar interferometry. Surface displacements provide the basis for the detection of active slope instabilities, which are then further classified by using geomorphological indicators visible in optical satellite imagery. Additionally, the proximity of active landslides to tectonic lineaments, as well as regional seismicity, is analysed to investigate potential relationships and to provide an integrated river damming hazard potential. The results show that approximately 31% of all detected landslides would have a high damming hazard potential upon catastrophic failure, highlighting the importance of such phenomena for efficient long-term land use planning and management of hydropower plants.

show abstract

“…These include the low-angle Vakhsh Thrust and Petrovsky Thrust which link to the Main Pamir Thrust (MPT) further east (fig. 3;Hamburger et al 1992, Lukk et al 2008, Lou et al 2009, Evans et al 2009. Thrusting typically occurs along relatively weak Jurassic gypsum-rich layers as these are often observed on the fault hanging walls, implying a regional décollement horizon (Hamburger et al 1992).…”

Section: Tectonics and Geologymentioning

confidence: 99%

Slope Activity Analysis in the Rogun Catchment Area, Tajikistan, using Remote Sensing Techniques

Jones¹,

Manconi²,

Strom³

2020

Preprint

View full text Add to dashboard Cite

<p>The stability and lifetime of construction projects in mountain areas are strongly dependent on local slope activity. Hydropower projects in particular are often affected and endangered by landslide damming and flood wave generation due to slope failures, and thus extensive studies of ground surface instability are vital to assess associated hazards. The Rogun Hydropower Project HPP located in Tajikistan in the Vakhsh &#8211; Surkhob River network is currently under construction. The site lies within the seismically active Tien Shan and Pamir Mountain ranges of Central Asia and in particular the Peter the First Range. This region is marked by extreme topography, steep slopes and extensive valley networks and has experienced large and catastrophic slope failures in the past, of which a multitude have been triggered by earthquakes of magnitude M&#8805;4. Co-seismic failures are thus common in the area and present a high geotechnical hazard; however, to date no information on active slope instabilities in its catchment area exists.</p><p>Here we present an inventory of slope instabilities in the Rogun Dam catchment area based on optical and synthetic aperture radar differential interferometry (DInSAR) remote sensing techniques. Sentinel-1 multi&#8211;temporal differential interferograms are generated for summer periods of 2016 &#8211; 2018 to detect surface displacements. Slope velocities are estimated based on a comparison between differential interferograms, while landslide types are identified based on a geomorphological classification. A likelihood analysis is developed to understand the state of activity of slopes and provide a semi-quantitative confidence thereof. The collected data is subsequently integrated to perform spatial and statistical analyses in order to perform a proximity analysis, assess a co-seismic link and evaluate the damming hazard potential to the Rogun HPP. Results show that a clear majority of detected features are located within 10 km of major faults and in zones of high peak ground acceleration, indicating a potential seismic influence or triggering. Some active slopes show an increase in surface displacement after a particular earthquake event and equally suggest a potential link. Moreover, we developed a damming hazard analysis for slopes detected as active in Sentinel-1 differential interferograms, considering the likelihood of movements, their distance to rivers and faults, as well as estimated volume and velocity per year. The results indicate that a total of 29.6 % of all features constitute a high damming hazard potential in case of catastrophic failure, with 4.5 % located within 1 km of the Rogun Dam reservoir. Although many potential sites are not directly on the slopes rising above the future reservoir, hazardous locations in the catchment upstream pose a threat due to possibility of significant outburst floods in case of the dammed lake outburst.</p>

show abstract

Seismotectonic characteristics of the northern flank and axial part of the Tajik Depression (the Garm Geodynamic Research Area)

Cited by 11 publications

References 6 publications

Seismotectonics of the Tajik Basin and Surrounding Mountain Ranges

Seismotectonics of the Tajik Basin and Surrounding Mountain Ranges

Active landslides in the Rogun Catchment, Tajikistan, and their river damming hazard potential

Slope Activity Analysis in the Rogun Catchment Area, Tajikistan, using Remote Sensing Techniques

Contact Info

Product

Resources

About