Premium
Shallow mantle velocities beneath the southern Appalachians from Pn phases
Author(s) -
MacDougall Julia G.,
Fischer Karen M.,
Forsyth Donald W.,
Hawman Robert B.,
Wagner Lara S.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062714
Subject(s) - geology , mantle (geology) , terrane , crust , seismology , oceanic crust , subduction , ridge , geophysics , paleontology , tectonics
To constrain mantle structure that might contribute to the topography of the southern Appalachian Mountains, Pn phases from regional earthquakes recorded in northern Georgia by EarthScope Southeastern Suture of the Appalachian Margin Experiment and Transportable Array stations were used to solve for shallow mantle P wave velocities. Mantle velocities vary laterally, with values of 7.6–7.8 km/s beneath the higher elevations of the Blue Ridge terrane and northwestern flank of the Inner Piedmont terranes and values of 8.3–8.5 km/s farther south where elevation is lower. The zone of low‐velocity mantle could represent a source of buoyancy that helps to support the higher elevations, in addition to the root of thickened crust that also exists beneath the mountains.