Simplified map of the Southwest Iberia segment of the Africa–Eurasia plate boundary (IMAGE)
Caption
To the west, it is possible to recognize two main structures: the Gloria Fault, which is generally considered the main trace of the present-day plate boundary, and the seemingly less active Tydeman Fracture Zone (although this segment of the plate boundary is often referred to as diffuse1,48). Both these structures have experienced high-magnitude earthquakes. To the east, their linear morphological traces gradually give way to thrust fault systems that uplift the seafloor, forming two major bathymetric highs, the Coral Patch Seamount and the Gorringe Bank, that delimit the Horseshoe Abyssal Plain (see also Extended Data Fig. 1). This region has unleashed some of the major historical and instrumental earthquakes in the Atlantic region. Although the precise location of the historical earthquakes is unknown, probable locations are given. For the instrumental earthquakes, the circles roughly correspond to the uncertainties in their locations1,4,5,6,7,16. A more detailed structural map of the Horseshoe Abyssal Plain and surrounding areas is provided in Extended Data Fig. 2. The black arrow indicates the Africa–Eurasia convergence direction in the SW Iberia region for a fixed Eurasian plate48. The West Iberian margin is a classic example of a hyperextended magma-poor margin in which the continental and oceanic crusts are separated by a stripe of exhumed serpentinized mantle (light green)12,24,49. The projection of the seismic anomaly of Fig. 2a is depicted in darker green. Basemap created with the ArcGIS® software by Esri using data available from GEBCO (https://www.gebco.net/). Seismicity data are available at http://www.isc.ac.uk.
Credit
Duarte, J.C., Riel, N., Civiero, C. et al.
Usage Restrictions
Credit must be given to the creator.
License
CC BY