Open AccessLithospheric strength and strain localization in continental extension from observations of the East African Rift
Author(s) -
Kogan L.,
Fisseha S.,
Bendick R.,
Reilinger R.,
McClusky S.,
King R.,
Solomon T.
Publication year - 2012
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011jb008516
Subject(s) - geology , lithosphere , rift , east african rift , mantle (geology) , triple junction , extensional definition , half graben , seismology , extensional tectonics , continental margin , continental crust , rift zone , geophysics , tectonics
GPS observations along three profiles across the Ethiopian Rift and Afar triple junction record differences in the length scale over which extension is accommodated. In the Afar region, where the mantle lithosphere is nearly or entirely absent, measurable extension occurs over ∼175 km; in the northern Ethiopian Rift, where the mantle lithosphere is anomalously thin and hot, extensional strain occurs over ∼85 km, extending beyond the structural rift valley; in the southern Ethiopian Rift, where the mantle lithosphere approaches standard continental thickness, extensional strain occurs over <10 km. This trend of increasingly distributed deformation contrasts with the standard model where continental rifts become mid‐ocean spreading centers through strain localization.