Elemental concentration of U, Th and K in tectonically active regions of Khari River basin, Kachchh, Western India

2011 ◽  
Vol 290 (1) ◽  
pp. 191-196 ◽  
Author(s):  
Himansu Kumar Kundu ◽  
M. G. Thakkar
Keyword(s):  
River Basin ◽  
Elemental Concentration ◽  
Active Regions ◽  
Western India ◽  
Tectonically Active

scholarly journals Estimation of absolute stress in the hypocentral region of the 2019 Ridgecrest, California, earthquakes

2020 ◽  
Author(s):  
Yuri Fialko
Keyword(s):  
Seismic Data ◽  
Plate Tectonics ◽  
Active Faults ◽  
Active Regions ◽  
Seismogenic Zone ◽  
Shear Stresses ◽  
Strong Earthquakes ◽  
Frictional Strength ◽  
Tectonically Active ◽  
Weak Fault

Abstract Strength of the upper brittle part of the Earth's lithosphere controls deformation styles in tectonically active regions, surface topography, seismicity, and the occurrence of plate tectonics, yet it remains one of the least constrained and most debated quantities in geophysics. Seismic data (in particular, earthquake focal mechanisms) have been used to infer orientation of the principal stress axes. Here I show that the focal mechanism data can be combined with information from precise earthquake locations to place robust constraints not only on the orientation, but also on the magnitude of absolute stress at depth. The proposed method uses machine learning to identify quasi-linear clusters of seismicity associated with active faults. A distribution of the relative attitudes of conjugate faults carries information about the amplitude and spatial heterogeneity of the deviatoric stress and frictional strength in the seismogenic zone. The observed diversity of dihedral angles between conjugate faults in the Ridgecrest (California, USA) area that hosted a recent sequence of strong earthquakes suggests the effective coefficient of friction of 0.4-0.6, and depth-averaged shear stresses on the order of 25-40 MPa, intermediate between predictions of the "strong" and "weak" fault theories.

scholarly journals Moment magnitude estimates for Central Anatolian earthquakes using coda waves

2019 ◽  
Author(s):  
Tuna Eken
Keyword(s):  
Empirical Relation ◽  
Active Regions ◽  
Moment Magnitude ◽  
Central Anatolia ◽  
Coda Wave ◽  
Seismic Experiment ◽  
Tectonically Active ◽  
Passive Seismic ◽  
Passive Seismic Experiment ◽  
Good Agreement

Abstract. Proper estimate of moment magnitude that is a physical measure of the energy released at earthquake source is essential for better seismic hazard assessments in tectonically active regions. Here a coda wave modeling approach that enables the source displacement spectrum modeling of examined event was used to estimate moment magnitude of central Anatolia earthquakes. To achieve this aim, three component waveforms of local earthquakes with magnitudes 2.0 ≤ ML ≤ 5.2 recorded at 72 seismic stations which have been operated between 2013 and 2015 within the framework of the CD-CAT passive seismic experiment. An inversion on the coda wave traces of each selected single event in our database was performed in five different frequency bands between 0.75 and 12 Hz. Our resultant moment magnitudes (MW-coda) exhibit a good agreement with routinely reported local magnitude (ML) estimates for study area. Finally, we present an empirical relation between MW-coda and ML for central Anatolian earthquakes.

scholarly journals The origins and implications of paleochannels in hyperarid, tectonically active regions: The northern Atacama Desert, Chile

2020 ◽  
Vol 185 ◽  
pp. 103083 ◽  
Author(s):  
S.A. Binnie ◽  
K.R. Reicherter ◽  
P. Victor ◽  
G. González ◽  
A. Binnie ◽  
...  
Keyword(s):  
Atacama Desert ◽  
Active Regions ◽  
Tectonically Active

Influence of hydro-geochemical processes on groundwater quality through geostatistical techniques in Kadava River basin, Western India

2018 ◽  
Vol 12 (1) ◽  
Author(s):  
Vasant Madhav Wagh ◽  
Dipak Baburao Panaskar ◽  
James A. Jacobs ◽  
Shrikant Vitthal Mukate ◽  
Aniket Avinash Muley ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
River Basin ◽  
Western India ◽  
Geochemical Processes ◽  
Geostatistical Techniques

scholarly journals Optical Dating of Sediments in Khari River Basin and Slip Rate Along Katrol Hill Fault (KHF), Kachchh, India

2010 ◽  
Vol 37 (-1) ◽  
pp. 21-28 ◽  
Author(s):  
Himansu Kundu ◽  
M. Thakkar ◽  
R. Biswas ◽  
A. Singhvi
Keyword(s):  
Lower Bound ◽  
River Basin ◽  
Central Region ◽  
Late Quaternary ◽  
Slip Rate ◽  
Western India ◽  
Fluvial Sediments ◽  
Optical Dating ◽  
The Past ◽  
The Future

Optical Dating of Sediments in Khari River Basin and Slip Rate Along Katrol Hill Fault (KHF), Kachchh, India In the central region of Mainland Kachchh, Western India, the Katrol Hill Fault (KHF) is one of the major E-W trending faults. An understanding of the episodes of reactivation during the past has a bearing on the future seismicity in the region. These reactivations are manifested by offset of elevation of fluvial sediments and scarp-derived colluvium in the Khari River basin, SE of Bharasar (23°11'36.5"N, 69°35'22.6"E). Stratigraphic offsets of the sediments at this site suggest three episodes of reactivation of the KHF during the late Quaternary. Optical dating of samples from sediment strata and top layer of scarp-derived colluvium using Natural Sensitivity Corrected - Single Aliquot Regenerative (NCF-SAR) protocol suggested that these events occurred during the past ~30 ka, with the most recent historic episode around 3.0 ka. Given that a part of the slip recorded in the form of sediments offset, was lost due to erosion after faulting, a lower bound to the time averaged slip rate of the segment of KHF, is inferred to be > 0.23 mm/a during the past 30 ka.

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