Publication Date:
2017-04-04
Description:
The Gibraltar Orogenic Arc, in the Western Mediterranean, represents a complex region of active deformation related to the oblique Nubia-Eurasia convergence process. To increase the knowledge on the ongoing active processes in this region, we have used the most up-to-date and comprehensive geodetic crustal motion and stress fields. To this end, we analyzed both continuous and campaign-mode GPS data collected between 1999.00 and 2011.00 across the area and compiled a multidisciplinary dataset of well-constrained stress indicators to be compared with the geodetic results. The main results highlight the oblique nature of the Nubia-Eurasia convergence, which provides the largest component of the observed stress-pattern and is responsible for a significant strain-rate field along the Gibraltar Orogenic Arc. We discuss our findings with respect to available geological, seismological and geophysical data in order to verify their coherency compared to more relevant geodynamical models proposed in literature. According to previous studies, we confirmed how much of the secondary stress-pattern can be related to the gravitational potential energy field, which may also be responsible for some 2D stress - strain-rate angular discrepancies observed in large areas of the Betics. In addition, taking into account the sub-orthogonal azimuthal relationship between the SHmax and εhmin directions and the Fast Polarization Directions, we conjectured a deep dynamic process controlling both the crustal stress field and the surface deformation on large areas of the orogenic arc. Finally, although the models proposed to explain the geodynamic pattern of the Gibraltar Orogenic Arc are supported by a discrete number of geological and geophysical observations, it is only the back-arc extension and westward rollback model that is able to adequately account for the vast majority of the observations. Based on our findings and other evidences, we retain that this process could still be active beneath the Gibraltar Orogenic Arc.
Description:
This research has been supported by the Spanish MICINN projects PCI2006-A7-0660 and AYA2010-17448, an Ontario Early Researcher Award, and the NSERC Canada and Aon Benfield/ICLR IRC in Earthquake Hazard Assessment. This research is a contribution to the Moncloa Campus of International Excellence (UCM-UPM, CSIC).
Description:
Published
Description:
1071–1088
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
restricted
Keywords:
Gibraltar Orogenic Arc
;
Stress field
;
Geodesy
;
strain-rate field
;
delamination
;
Back-arc extension and rollback
;
slab break-off
;
crustal extrusion and lateral escaping
;
Plate tectonic
;
passive subduction
;
04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
