Tomography reveals buoyant asthenosphere accumulating beneath the Juan de Fuca plate.
Science
; 353(6306): 1406-1408, 2016 09 23.
Article
em En
| MEDLINE
| ID: mdl-27708032
ABSTRACT
The boundary between Earth's strong lithospheric plates and the underlying mantle asthenosphere corresponds to an abrupt seismic velocity decrease and electrical conductivity increase with depth, perhaps indicating a thin, weak layer that may strongly influence plate motion dynamics. The behavior of such a layer at subduction zones remains unexplored. We present a tomographic model, derived from on- and offshore seismic experiments, that reveals a strong low-velocity feature beneath the subducting Juan de Fuca slab along the entire Cascadia subduction zone. Through simple geodynamic arguments, we propose that this low-velocity feature is the accumulation of material from a thin, weak, buoyant layer present beneath the entire oceanic lithosphere. The presence of this feature could have major implications for our understanding of the asthenosphere and subduction zone dynamics.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Science
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos