Focal Mechanisms for Subcrustal Earthquakes Beneath the Gibraltar Arc

Santos-Bueno, N. (Universidad de Zaragoza) ; Fernández-García, C. ; Stich, D. ; Mancilla, F.D.L. ; Martín, R. ; Molina-Aguilera, A. ; Morales, J.

Resumen: Intermediate deep earthquakes are usually associated with active subduction, and show mostly dip-slip faulting mechanisms aligned with the downgoing oceanic lithosphere. Forty-two new focal mechanisms from 50- to 100-km depth beneath the Gibraltar Arc and Alboran Sea show different characteristics. The most abundant solutions are strike-slip mechanisms, in agreement with relative plate motion between Nubia and Eurasia. Additional reverse faulting mechanisms indicate compression in direction of absolute plate motion, reproducing the basal drag of the mantle on the hanging lithosphere. In turn, no signature of ongoing subduction was found. Migrated sections of P wave receiver functions suggest that a significant part of intermediate deep seismicity is produced within the stalled remnants of Jurassic age, oceanic lithosphere that once formed the connection between the Alpine Tethys and the central Atlantic and later has been buried beneath the Gibraltar Arc.

Idioma: Inglés

DOI: 10.1029/2018GL081587

Año: 2019

Publicado en: GEOPHYSICAL RESEARCH LETTERS 46, 5 (2019), 2534-2543
ISSN: 0094-8276

Factor impacto JCR: 4.497 (2019)

Categ. JCR: GEOSCIENCES, MULTIDISCIPLINARY rank: 17 / 198 = 0.086 (2019) - Q1 - T1

Factor impacto SCIMAGO: 2.442 - Geophysics (Q1) - Earth and Planetary Sciences (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/CGL2015-67130-C2-2-R

Tipo y forma: Article (Published version)

Área (Departamento): Área Estratigrafía (Dpto. Ciencias de la Tierra)