Yellowstone hot spot: Contemporary tectonics and crustal properties from earthquake and aeromagnetic data

Abstract

A compilation of aeromagnetic and new earthquake data is used to characterize the current tectonic activity and crustal properties of the Yellowstone hot spot. Earthquakes located during detailed surveys from 1972 to 1976 occurred west and northeast of the Yellowstone caldera along east‐west zones and south of the caldera in north‐south zones. The change in trend suggests that Yellowstone is at a vertex of the contemporary tectonic patterns. Seismicity showed variations of maximum focal depths from ∼20 km outside the Yellowstone caldera to ∼5 km inside the caldera. The frequency of earthquake occurrence was markedly lower within the caldera. Fault plane solutions showed general north‐south extension west of the caldera, a suggestion of radial compression near the western caldera rim, and northeast to southeast extension south of the caldera. Spectral analyses of aeromagnetic data indicate the Curie isotherm to be 10±3 km below sea level at the periphery of the caldera. These data support the hypothesis of a magma source within the crust for the Yellowstone hydrothermal activity, but they do not bear on the definition of a deep mantle source for the Yellowstone hot spot.

Regional variations of the cutoff depth of seismicity in the crust and their relation to heat flow and large inland-earthquakes.

“…Depth sections of seismicity similar to that for the Izu-Oshima volcano have been obtained by observational networks for several active volcanoes: for example, the Sakurajima (Nishi, 1978), Aso (Sudo et al, 1984), Unzen (Matsuo, 1985), and Kirishima (Ida et al, 1986) volcanoes. Smith et al (1977) noted similar features in the focal-depth distribution and thermal structure of the Yellowstone hot spot. Shallow cutoff depths of seismicity can also be seen in many geothermal areas (e.g., NEDO, 1983).…”

Estimating depth to the bottom of magnetic sources at Wikki Warm Spring region, northeastern Nigeria, using fractal distribution of sources approach

“…One of the methods for examining the thermal structure of the crust is the estimation of the CPD using aeromagnetic data (Smith et al, 1977;Okubo et al, 1985Okubo et al, , 1989Okubo et al, , 1994Okubo et al, , 2003Tsokas et al, 1998;Tanaka et al, 1999;Stampolidis and Tsokas, 2002;Dolmaz et al, 2005;Ates et al, 2005;Aydin et al, 2005;Qingqing et al, 2008;Li et al, 2010;Li, 2011;Bilim, 2011;Manea and Manea, 2011;Abd El Nabi, 2012;Hisarli et al, 2012;Saleh et al, 2013;Sayed et al, 2013;Abraham et al, 2014;Obande et al, 2014;Starostenko et al, 2014). Various studies have shown correlations between Curie temperature depths and average crustal temperatures, leading to viable conclusions regarding lithospheric thermal conditions in a number of regions around the world (Ross et al, 2006;Rajaram, 2007;Bouligand et al, 2009).…”

Curie Point Depths of Macedonia and Thrace, N. Greece

“…Aeromagnetic data have been used at various parts of the world in order to estimate Curie point depths (e.g., VACQUIER and AFFLECK, 1941;SERSON and HANNAFORD, 1957;BHATTACHARYYA and MORLEY, 1965;SCHELLINGER, 1972;DEMENITSKAYA et al, 1973;SMITH et al, 1974SMITH et al, , 1977LEU, 1975, 1977;BYERLY and STOLT, 1977;SHUEY et al, 1977;WASILEWSKI et al, 1979;BLAKELY and HASSANZADEH, 1981;CONNARD et al, 1983;HUPPUNEN, 1983;MAYHEW, 1982MAYHEW, , 1985OKUBO et al, 1985OKUBO et al, , 1989TSELENTIS and DRAKOPOULOS, 1988;BLAKELY, 1988;SMITH et al, 1994;TSO¨KAS et al, 1998).…”