EGU26-12584, updated on 14 Mar 2026
https://doi.org/10.5194/egusphere-egu26-12584
EGU General Assembly 2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
Poster | Thursday, 07 May, 14:00–15:45 (CEST), Display time Thursday, 07 May, 14:00–18:00
 
Hall X2, X2.89
The Africa-Eurasia transform plate boundary – Insights from the morphostructure of the Gloria Fault, NE Atlantic
Cristina Roque1,2, Sónia Manzoni3, João Duarte2,4, Susana Gonçalves1,5, Luis Batista2,5, and Miguel Souto1
Cristina Roque et al.
  • 1EMEPC, Paço de Arcos, Portugal (croque@emepc-portugal.org)
  • 2Instituto Dom Luiz (IDL), Faculty of Sciences, University of Lisbon, Campo Grande, Lisbon, Portugal
  • 3Agrupamento de Escolas de Alvalade, Lisbon, Portugal
  • 4Earth Sciences and Energy Department, Faculty of Sciences, University of Lisbon, Portugal
  • 5Instituto Português do Mar e da Atmosfera (IPMA), Lisbon, Portugal

The Azores-Gibraltar Plate Boundary (AGPB) materializes the present-day westernmost segment of the Africa (Nubia)-Eurasia plate boundary, and connects the Azores triple junction, at the west, to the Gibraltar orogenic arc, at the east. The Gloria Fault corresponds to its central and transform segment, trending E-W to WNW-ESE between 24° W and 14°30’W and showing dextral strike-slip motion. This feature corresponds to one of the rare examples of a ridge-transform fault-orogenic arc plate configuration worldwide. The Gloria Faults has also been the site of great-magnitude earthquakes, such as the 25 November 1941 (Mw8.4), the second-largest oceanic strike-slip event recorded worldwide. In spite of the studies carried out in this AGPB segment, the seismotectonics of the Gloria Fault is still poorly known. In this work we present a detailed morphostructural characterization of the Gloria Fault and discuss the relationship between the main morphostructures and seismicity, based on i) the geomorphological analysis of unpublished multibeam bathymetry collected in the scope of the Project of Extension of Continental Shelf; ii) correlation of the main morphostructures identified with instrumental seismicity and microseismicity records available from public catalogues (SHARE, USGS, IPMA) and published by several authors, and iii) profile gravity analysis based on SGG-UGM-2 satellite gravity data compilation.

Based on the morphostructural, seismotectonic and gravimetric analysis we propose the existence of a Gloria Fault Transform System, which includes the several morphological features relate to its transcurrent motion (e.g., central valley, transverse ridges, restraining bend, Western Gap, Eastern Ridge), and the two main seismically active structures in the area, located at north and south of the Gloria Fault. This suggests that, at present, the stress due to the motion of the Africa-Eurasia plates is accommodated by seafloor deformation along a wide E-W stripe.

This work is supported by FCT, I.P./MCTES through national funds (PIDDAC): LA/P/0068/2020 - https://doi.org/10.54499/LA/P/0068/2020 , UID/50019/2025, https://doi.org/10.54499/UID/PRR/50019/2025, UID/PRR2/50019/2025.

How to cite: Roque, C., Manzoni, S., Duarte, J., Gonçalves, S., Batista, L., and Souto, M.: The Africa-Eurasia transform plate boundary – Insights from the morphostructure of the Gloria Fault, NE Atlantic, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12584, https://doi.org/10.5194/egusphere-egu26-12584, 2026.