Occurrences of large-magnitude earthquakes in the Kachchh region, Gujarat, western India: Tectonic implications

Earthquake Shocks Around Delhi-NCR and the Adjoining Himalayan Front: A Seismotectonic Perspective

“…In addition to the earthquakes in the Kachchh region, two other events (1969 M w 5.3 Mt. Abu and 2009 M w 5.1 Barmer at 15 and 39 km depth, respectively) were also reported along regional fault systems demarcating the area (Khan et al, 2016).…”

“…The 2001 M w 7.6 Bhuj earthquake was considered to be the result of stress propagation from the Himalayas (Copley et al, 2011) or the Suleiman Range (Stein et al, 2002;Khan et al, 2016). The analysis of Khan et al (2016) indicates that the far-field stress generated by the collision resistance between the Indian and Eurasian plates and anticlockwise rotation of the Indian plate are the main factors behind the stress accumulation in the western India and its periodic release through earthquakes. In addition to the earthquakes in the Kachchh region, two other events (1969 M w 5.3 Mt.…”

“…The enormity of deformation of the orogenic process has resulted in the development of unconformity in the floor of the Bay of Bengal, folding and faulting in the equatorial Indian Ocean, and the evolution of basins and ridges near the foothills of the Himalayas-all in response to tectonic processes in the orogen that evolved during Miocene-Pliocene time (Cochran, 1990;Curray, 2005;Gordon, 2009). Thus, the active resistance to the under thrusting distributes and perturbs the stress fields up to the Indian Ocean, and accounts for occasional incidents of great intraplate earthquakes Aggarwal et al, 2016;Khan et al, 2016;Khan et al, 2020). Further, the excess weight of the orogeny is supported in parts by the strength of the Indian plate, which distributes the load by flexing down along the ∼1000 km laterally extended and isostatically over-compensated Indo-Gangetic Plains (e.g., Lyon-Caen and Molnar, 1983;Tandon et al, 2014).…”

“…The faultbound 2001 Bhuj earthquake occurred at the shallow-level of the lower crust caused widespread damage with a toll of ∼20,000 human lives. Small-to-moderate magnitude aftershocks were recorded in different parts of northern Gujarat till the end of 2014 (Khan et al, 2016;Aggarwal et al, 2016). In addition, the incidences of historical major earthquakes (1819 M w 7.8 Allahbund and 1956 M w 6.0 Anjar, Figure 1C) in the Bhuj region had rattled the basic tenet of intraplate origin of damaging earthquakes (Chung and Gao, 1995).…”

Change of stress patterns during 2004 MW 9.3 off‐Sumatra mega‐event: Insights from ridge–trench interaction for plate margin deformation

“…The development of the deformation zone in the north‐eastern Indian Ocean is reported to have been initiated in the Early Miocene at 18–14 Ma (Bull, DeMets, Krishna, Sanderson, & Merkouriev, ; Krishna et al, ). The active resistance during underthrusting of the Indo‐Australian Plate along the Himalayan boundary initiated the reverse transmission of a compressive stress field within the plate interior, which accounts for the occasional incidences of great intraplate earthquakes (Aggarwal, Khan, Mohanty, & Roumelioti, ; Khan, Ansari, & Mohanty, ; Khan, Mohanty, Sinha, & Singh, ) and the neotectonic activities (Biswas, ). The deformation of the Indo‐Australian lithosphere, unconformity in the floor of the Bay of Bengal, concomitant folding and faulting in the equatorial Indian Ocean, and the lateral evolutions of basins and ridges near the foothills of the Himalayas are the tectonic responses that evolved during the Oligocene‐Miocene time (Ansari & Khan, ; Cochran, ; Curray, ; Gordon, , and references therein).…”