Document type
Journal articles
Document subtype
Full paper
Title
A sanity check for earthquake recurrence models used in PSHA of slowly deforming regions: the case of SW Iberia
Participants in the publication
Margarida Ramalho (Author)
Luis Matias (Author)
Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749–016, Lisboa, Portugal
Dep. Engenharia Geográfica, Geofísica e Energia
Marta Neres (Author)
Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749–016, Lisboa, Portugal
Michele M. C. Carafa (Author)
Alexandra Carvalho (Author)
Paula Teves-Costa (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749–016, Lisboa, Portugal
Summary
Probabilistic seismic hazard assessment (PSHA), despite its deep criticism, is still the most common tool used to decide on the acceptable seismic risk and corresponding mitigation measures. We propose two consistency tests to address the variability of earthquake generation models found in PSHA studies: (i) one rule-of-thumb test where the seismic moment release from the model is converted to an average slip on a typical fault and compared with known plate kinematics or GNSS deformation field and (ii) a test where using a neotectonic model the computed deformation is converted into seismic moment release and to a synthetic earthquake catalogue. We apply these tests to W and SW Iberia slowly deforming region, where two earthquake source areas are investigated: (1) the Lower Tagus Valley, one of the largest seismic risk zones of Portugal; and (2) the offshore SW Iberia area, considered to be the source for the 1 November 1755 event (M ∼ 8.7). Results show that some of the earthquake source models should be considered suspicious, given their high/low moment release when compared to the expected values from GNSS observations or neotectonic modelling. This analysis allowed for a downgrade of the weight of poorly compliant models in the PSHA analysis, and thus for a more realistic hazard assessment, and can be integrated in other studies of similar settings.
Date of Publication
2022-01-25
Where published
Natural Hazards and Earth System Sciences
Publication Identifiers
Publisher
Copernicus GmbH
Number of pages
22
Starting page
117
Last page
138
Document Identifiers
DOI -
https://doi.org/10.5194/nhess-22-117-2022
URL -
http://dx.doi.org/10.5194/nhess-22-117-2022
Rankings
SCIMAGO Q1 (2023) - 1.22 - Earth and Planetary Sciences