Active Tectonics and Paleoseismicity of the Eastern Issyk-Kul Basin (Kyrgyzstan, Tien Shan)

2021 ◽  
Vol 62 (03) ◽  
pp. 263-277
Author(s):  
A.M. Korzhenkov ◽  
E.V. Deev ◽  
I.V. Turova ◽  
S.V. Abdieva ◽  
S.S. Ivanov ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Late Quaternary ◽  
Active Tectonics ◽  
Historical Earthquakes ◽  
Strike Slip ◽  
Tien Shan ◽  
Quaternary Sediments ◽  
The South ◽  
Large Earthquakes ◽  
Tectonic Movements

Abstract —The Malyi Orgochor, Orgochor, Birbash, Sukhoi Ridge, Ichketosma, and Tosma uplifts in the eastern Issyk-Kul basin are fault-related anticlinal folds composed of Neogene and Quaternary sediments involved in tectonic movements. The folds have asymmetric transversal profiles, with low-angle southern limbs and steep northern limbs cut by segments of the South Issyk-Kul and Karkara reverse faults reactivated in the late Quaternary. The location and geometry of the two faults, which both show reverse and left-lateral strike slip components, correspond to neotectonic propagation of deformation from the Terskey-Ala-Too Range over almost the whole eastern Issyk-Kul basin. Judging by primary and secondary coseismic surface deformation in the area, the South Issyk-Kul and Karkara faults repeatedly generated large earthquakes (M ≥ 7, I ≥ 9) in the Late Pleistocene and Holocene. According to trenching results, the historical earthquakes that occurred in the first and 10–11th centuries accommodated motions on the South Issyk-Kul fault. The new seismotectonic and paleoseismicity data from the eastern Issyk-Kul basin provide updates to its seismic potential.

scholarly journals Slip‐rate on the Main Köpetdag (Kopeh Dagh) Strike‐slip fault, Turkmenistan, and the active tectonics of the South Caspian

Tectonics ◽  
2021 ◽  
Author(s):  
Richard Thomas Walker ◽  
Y. Bezmenov ◽  
G. Begenjev ◽  
S. Carolin ◽  
N. Dodds ◽  
...  
Keyword(s):  
Active Tectonics ◽  
Slip Rate ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
The South

scholarly journals Constraints on the precision of SAR in equivalent dose estimations close to saturation in quartz

2011 ◽  
Vol 38 (4) ◽  
pp. 413-423 ◽  
Author(s):  
Constantin Athanassas
Keyword(s):  
Growth Curve ◽  
Late Quaternary ◽  
Equivalent Dose ◽  
Curve Shape ◽  
Large Scatter ◽  
Dose Estimation ◽  
Quaternary Sediments ◽  
The South ◽  
Of Greece

Abstract Difficulties in evaluating accurate equivalent doses for Late Quaternary sediments from the south coasts of Greece arose in the course of SAR measurements. Large scatter among apparent equivalent doses perplexed the evaluation of accurate mean estimates in circumstances where very large doses were involved. Besides, dose recovery experiments revealed that when intersection of the natural signal occurs onto the saturating segment of the growth curve, a distinct relationship between De and growth curve shape occurs. At very low slope angles, SAR tends to overestimate the recovered dose. The mechanism which controls the spread in equivalent dose estimation is investigated.

scholarly journals Depositional Environments and History of Late Quaternary Sediments in Hudson Strait and Ungava Bay: Further Evidence from Seismic and Biostratigraphic Data

2007 ◽  
Vol 46 (3) ◽  
pp. 311-329 ◽  
Author(s):  
Brian MacLean ◽  
Gustav Vilks ◽  
Bhan Deonarine
Keyword(s):  
Late Quaternary ◽  
Depositional Environments ◽  
Quaternary Sediments ◽  
The South ◽  
Bay Area ◽  
South Central ◽  
History Of ◽  
Ams Dating ◽  
Seafloor Sediments ◽  
Glaciomarine Sediments

ABSTRACT Regional ship-borne investigations of seafloor sediments provide further information on late Quaternary depositional environments and history in the Hudson Strait-Ungava Bay region. Greatest sediment thicknesses, up to 130 m, occur in the large basin in eastern Hudson Strait and in the western Hudson Strait basin north of Charles Island. Significant deposits are also present in basins southwest of Charles Island, along the south central part of the Strait, and in the southern part of Ungava Bay. Glacial drift deposits are widespread, but glaciomarine and postglacial sediments mainly occur in the basinal areas, with glaciomarine sediments generally predominating. Glaciomarine sediments are laterally transitional to glacial drift in the south central part of the Strait, and at many other basin margins. AMS dating of the deepest shells found within three cores from the glaciomarine sequences in the Wakeham Bay-Baie Héricart region of south central Hudson Strait yielded ages of 8390 ± 70,8420 ± 80, and 8520 ± 80 BP. Sequences underlying the dated intervals may contain time equivalents of glaciomarine sediments 1000-2000 years older found onshore in the Deception Bay area by Gray, Bruneau, and others.

The role of the remarkable Seram-Kumawa strike-slip fault in the tectonic process of the northern Banda Arc system

2020 ◽  
Author(s):  
Xiaodong Yang ◽  
Satish C. Singh ◽  
Ian Deighton
Keyword(s):  
Subduction Zones ◽  
Surface Deformation ◽  
Active Tectonics ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Benioff Zone ◽  
Accretionary Wedge ◽  
Geophysical Research ◽  
Fault Plane Solutions ◽  
Banda Arc

<p><span>The Banda Arc system is sited in a junction of </span>convergence between the Eurasian, Indo-Australian, Philippine and Pacific plates<span>. It </span>has a remarkable 180° curve in the Benioff zone<span>. Two fundamental ideas have been invoked to explain this significant subduction-arc orientation change: (1) bent subduction zone around the Banda Sea (Hamilton, 1979; Spakman and Hall, 2010; Hall, 2012)</span>, or (2) oppositely dipping subduction zones (Cardwell and Isacks, 1978; McCaffrey, 1989), b<span>ut no general agreement exists as to the cause of this curvature. However, a WNW-trending strike-slip fault, i.e. Seram-Kumawa fault, is observed at the north-eastern end of the Arc, cutting through the Seram accretionary wedge, prism and trench and seems to continue on the subducting plate (Hall et al., 2017). This fault is either inactive or locked temporarily at the present day, because there are very few strike-slip events along its trend while there are many thrust earthquakes on its north and northwest side. A few essential questions remain unanswered about this fault in relation to the evolution of the Banda Arc. For instance, what is the origin of this fault, what role does it play in the tectonic processes and large earthquakes along the Banda Arc. Could this fault eventually break-up the Banda Arc? What is its tectonic implication on the evolution of other highly curved subduction-arc systems? To address these questions, we will carry out a comprehensive investigation into active tectonics and seismicity occurrence along the northeast Banda Arc using high-resolution bathymetry, 2D marine seismic profiles and earthquake data. </span></p><p><strong>Reference:</strong></p><p><span><span>Cardwell, R.K. and Isacks, B.L., 1978. Geometry of the subducted lithosphere beneath the Banda Sea in eastern Indonesia from seismicity and fault plane solutions. Journal of Geophysical Research: Solid Earth, 83(B6): 2825-2838.</span></span></p><p><span>Hall, R., 2012. Late Jurassic–Cenozoic reconstructions of the Indonesian region and the Indian Ocean. Tectonophysics, 570: 1-41.</span></p><p><span>Hall, R., Patria, A., Adhitama, R., Pownall, J.M. and White, L.T., 2017. Seram, the Seram Trough, the Aru Trough, the Tanimbar Trough and the Weber Deep: A new look at major structures in the eastern Banda Arc.</span></p><p><span>Hamilton, W.B., 1979. Tectonics of the Indonesian region. US Govt. Print. Off.</span></p><p><span>McCaffrey, R., 1989. Seismological constraints and speculations on Banda Arc tectonics. Netherlands Journal of Sea Research, 24(2-3): 141-152.</span></p><p><span>Spakman, W. and Hall, R., 2010. Surface deformation and slab–mantle interaction during Banda arc subduction rollback. Nature Geoscience, 3(8): 562.</span></p><p> </p>

scholarly journals The Dzhungarian fault: Late Quaternary tectonics and slip rate of a major right-lateral strike-slip fault in the northern Tien Shan region

2013 ◽  
Vol 118 (10) ◽  
pp. 5681-5698 ◽  
Author(s):  
G. E. Campbell ◽  
R. T. Walker ◽  
K. Abdrakhmatov ◽  
JL. Schwenninger ◽  
J. Jackson ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Slip Rate ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Tien Shan ◽  
Lateral Strike Slip ◽  
Northern Tien Shan

scholarly journals Palaeo-earthquake magnitudes on the Dzhungarian fault, N. Tien shan, and implications for the rupture processes of intraplate strike-slip faults

2020 ◽  
Author(s):  
Chia-Hsin Tsai ◽  
Richard Walker ◽  
Simon Daout ◽  
Kanatbek Abdrakhmatov ◽  
Aidyn Mukambayev ◽  
...  
Keyword(s):  
Kinematic Model ◽  
Strike Slip ◽  
Tien Shan ◽  
High Mountain ◽  
Short Term ◽  
Lithospheric Deformation ◽  
Large Earthquakes ◽  
Northern Tien Shan ◽  
Fault Length

<p>Long-term and present-day crustal deformation in the northern Tien Shan is poorly known, but is a key to understanding the mode of lithospheric deformation deep within the continental interiors, as well as the hazards posed by the slow-moving intraplate faults. Driven by the India-Asia collision, the NW-SE strike-slip faults and the E-W range-front thrust faults in the interior of Tien Shan together accommodate about 15-20 mm/yr of shortening. Here we focus on the NW-SE striking Dzhungarian fault (DZF) and the E-W striking Lepsy fault (LPF), which are large oblique strike-slip faults bounding the Dzhungarian Alatau, northern Tien Shan. Two large historical earthquakes in ~1716 and 1812 (Mw 8) were recorded in this region, and clear fault traces as well as scarps are visible from satellite images along some of the main faults. However, their geometries, slip rates, mode of deformation, expected earthquake magnitudes and recurrence interval have not been studied in details. A previous study suggested that the LPF ruptured in a seismic event around 400 yrBP that might be the 1716 earthquake known from historical records. Offsets of over 15 m were found over a fault length of 120 km, indicating a magnitude in the range Mw 7.5-8.2. The slip to length ratio for the LPF is unusally high, suggesting either that faults in this region are capable of generating very large earthquakes for a given fault length, or that the rupture length is underestimated.</p><p>Using a combination of high-resolution digital elevation models (DEMs) and orthophotos from High Mountain Asia (NASA), Pleiades optical imagery (CNES), drone photos and multi-temporal interferometric synthetic-aperture radar (InSAR) from the Sentinel-1 satellites, we identify the geomorphic signatures and quantify the long-term and short-term strain accumulation along the faults. The ~400 km DZF shows evidence for relatively ‘fresh’ rupturing along much of its length. We calculate an average lateral slip per event of 9.9 m from offset stacking analysis, which underlines the potential future large earthquakes on this fault. The proximity of the DZF and LPF ruptures and equivalent level of preservation opens the possibility that they were formed in a single earthquake event, with a moment-magnitude greater than 8. We also present estimates of long-term and short-term rates of slip across the DZF in order to estimate average recurrence intervals and to build a kinematic model of the faulting in the Northern Tien Shan.</p>

scholarly journals Seismic intensity assignments for the 2008 Andravida (NW Peloponnese, Greece) strike-slip event (June 8, Mw=6.4) based on the application of the Environmental Seismic Intensity scale (ESI 2007) and the European Macroseismic scale (EMS-98)

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Spyridon D. Mavroulis ◽  
Ioannis G. Fountoulis ◽  
Emmanuel N. Skourtsos ◽  
Efthymis L. Lekkas ◽  
Ioannis D. Papanikolaou
Keyword(s):  
Structural Damage ◽  
Surface Deformation ◽  
Active Tectonics ◽  
Geological Structure ◽  
Seismic Intensity ◽  
Strike Slip ◽  
Masonry Buildings ◽  
Small Surface ◽  
Geotechnical Characteristics ◽  
Slip Event

On June 8, 2008, a strike-slip earthquake (Mw=6.4) was generated NE of the Andravida town (NW Peloponnese, western Greece) due to the activation of the previously unknown western Achaia strike-slip fault zone (WAFZ). Extensive structural damage and earthquake environmental effects (EEE) were induced in the NW Peloponnese, offering the opportunity to test and compare the ESI 2007 and the EMS-98 intensity scales in a moderate strike-slip event. No primary EEE were induced, while secondary EEE including seismic fractures, liquefaction phenomena, slope movements and hydrological anomalies were widely observed covering an area of about 800 km<sup>2</sup>. The lack of primary effects and the relatively small surface deformation with respect to the earthquake magnitude is due to the thick Gavrovo flysch layer in the affected area that isolated and absorbed the subsurface deformation from the surface. According to the application of the EMS-98 scale, damage to masonry buildings ranged from grade 3 to 5, while damage in most of R/C buildings ranged from grade 1 to 3. A maximum ESI 2007 intensity VIII-IX is recorded, while the maximum EMS-98 intensity is IX. For all the sites where intensity VIII has been recorded the ESI 2007 and the EMS-98 agree, but for others the ESI 2007 intensities values are lower by one or two degrees than the corresponding EMS-98 ones, as it is clearly concluded from the comparison of the produced isoseismals. An exception to this rule is the Valmi village, where considerable structural damage occurs (IX<sub>EMS-98</sub>) along with the lack of significant EEE (V<sub>ESI 2007</sub>). This variability between the ESI 2007 and the EMS-98 intensity values is predominantly attributed to the vulnerability of old masonry buildings constructed with no seismic resistance design. Correlation of all existing data shows that the geological structure, the active tectonics, and the geotechnical characteristics of the alpine and post-alpine formations along with the construction type of buildings were of decisive importance in the damage and the EEE distribution.

scholarly journals Recent Tectonics in the Nepal Himalayas: A Synthesis

1995 ◽  
Vol 11 ◽  
Author(s):  
K. Kizaki
Keyword(s):  
Late Quaternary ◽  
Compressive Strain ◽  
Active Faults ◽  
The South ◽  
Main Central Thrust ◽  
River Terraces ◽  
Main Boundary Thrust ◽  
Recent Tectonics ◽  
Tectonic Movements ◽  
Different Parts

Geodetic surveys were earned out across the Main Central Thrust (MCT) at Dana (Kali Gandaki valley), and the Main Boundary Thrust (MBT) near Kerabari (SW of Pokhara) to obtain quantitative data on the tectonic movements along these boundary thrusts. The results have revealed that the MCT is no longer active, although the surveyed area near the MCT showed a 6 mm tilting to the south in four years. At the same time the surveyed points moved 3-4 cm to the west, indicating that the maximum compressive strain around the MCT in the area surveyed is acting along the NE-SW direction instead of the commonly assumed N-S direction. The measurements across the MBT, on the other hand, showed that the MBT is still quite active with an upliftment of 3 mm in four years. A northward tilt of the area just to the south of the MBT was also recorded. The study of river terraces in the Pokhara area indicated that the overlap of the older Ghachok Terrace by the younger Pokhara Terrace was due to tectonic movements and that the whole area between Pokhara and the upper reaches of the Seti River (north of Pokhara) has tilted to the south since the deposition of the Ghachok Formation or before. The study of river terraces along the Kali Gandaki valley showed that different parts of its N-S section were uplifted at different rates and the most upheaved sections of the terraces were found around Dana (near the MCT) and in the Mahabharat and Siwalik zones since the late Quaternary. The significance of the active faults in the understanding of Recent tectonics in the Nepal Himalayas is also discussed.

scholarly journals Recent and Late Quaternary dinoflagellate cysts from the area of the Greenland –Iceland –Faeroe –Scotland Ridge

1984 ◽  
Vol 3 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Rex Harland
Keyword(s):  
Continental Shelf ◽  
Late Quaternary ◽  
Dinoflagellate Cysts ◽  
Quaternary Sediments ◽  
The South ◽  
Northern Flank ◽  
Dinoflagellate Cyst ◽  
Southern Area

Abstract. Dinoflagellate cyst assemblages are described from Recent and Late Quaternary sediments recovered from Vema cores taken in the area of the Greenland – Iceland – Faeroe – Scotland Ridge. The dinoflagellate assemblage interpreted as indicating the Flandrian, “climatic” amelioration occurred in the sediments on the northern flank of the ridge whereas no evidence was found for this amelioration in the cores to the south. In the southern area, cyst assemblages proved an older climatic amelioration possibly of Eemian age. The potential for using dinoflagellate cysts to correlate oceanic and continental shelf areas is stressed.

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