Topic > Probable causes of intraplate earthquakes

The probable causes and determining factors related to the occurrence and distribution of intraplate earthquakes have proven to be very subtle. Different researchers have tried to explain this earthquake with different perceptions and to date several models have been proposed. In a global context, intraplate earthquakes have been found to occur along pre-existing zones of weakness within areas affected by the last major orogeny (Sykes 1978). Some of the models that explain the occurrence of intraplate earthquakes are intersecting faults (Talwani 1988, 1999); local stress concentration around the destabilized breaches (Campbell 1978); weak ductile zones in the lower crust (Zoback 1983), presence of fluids in the lower crust of ancient rift zones (Vinnik 1989), stress perturbations arising from buried rift pillows (Zoback and Richardson 1996), a weak zone in the lower crust ( Kenner and Segall 2000), rift crust (Johnston and Kanter 1990; Johnston et al. 1994; Schulte and Mooney 2005), craton edges (Mooney et al. 2012), areas of high heat flux (Liu and Zoback 1997), and lateral density variations (Stein et al. 1989). Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay In these models, mainly the upper crust satisfies seismogenic earthquakes which are governed by the forces generated by the plates. However, as the lower crust is weakened due to higher temperatures, the strength of the lithosphere decreases, resulting in moderate-magnitude earthquakes. Long (1988) proposed that seismicity due to intraplate earthquakes is a transient phenomenon caused by a perturbation of crustal strength due to disturbance of the hydraulic or thermal properties of the lower crust. Further models suggest that intraplate seismicity is due to perturbation of the regional stress field by forces associated with lithospheric bending after deglaciation, gravitational forces at structural boundaries, or sediment loading (Stein et al. 1979; Quinlan 1984; Grollimund & Zoback 2001; Goodacre & Hasegawa 1980; Chandrasekhar & Mishra 2002; Zoback (1992) suggested that large intraplate earthquakes occur due to the compressive stress field within the plate, which is a combination of the strength of the main plate and the local stress field associated with specific tectonic or geologic conditions. characteristics (such as lateral density contrasts, lateral force contrasts, and lithospheric bending). Recent data studies on the global stress model reveal that the stress field can have broader wavelengths extending from the plate scale to regional and local scales (Heidbach et al. 2010). Talwani (2014) and Khan et al. (2016) attempted to combine all these various models into one embedded model for intraplate earthquakes. They proposed that intraplate earthquakes occur in some geological areas where local stress is concentrated which supports the accumulation of local stresses, and this accumulated local stress field interacts with the regional tectonic stress field and ultimately leads to an earthquake. Sometimes, acclimatization of deformations can also allow the accumulation of a greater amount of stress field with transformation of the rheology of the constituent rocks and a failure can occur sufficient to generate earthquakes..