: Impact of sea-level rise on earthquake and landslide triggering offshore the Alentejo margin (SW Iberia)
Share
Metadata
Show full item recordDate
2016-12-01Type
articleKeywords
SEA-LEVELEARTHQUAKE
LANDSLIDE
ALENTEJO MARGIN
Abstract
Abstract Earthquakes and submarine landslides are recurrent and widespread manifestations of fault activity offshore SW Iberia. The present work tests the effects of sea-level rise on offshore fault systems using Coulomb stress change calculations across the Alentejo margin. Large-scale faults capable of generating large earthquakes and tsunamis in the region, especially NE–SW trending thrusts and WNW–ESE trending dextral strike-slip faults imaged at basement depths, are either blocked or unaffected by flexural effects related to sealevel changes. Large-magnitude earthquakes occurring along these structures may, therefore, be less frequent during periods of sea-level rise. In contrast, sea-level rise
promotes shallow fault ruptures within the sedimentary sequence along the continental slope and upper rise within distances of <100 km from the coast. The results suggest that the occurrence of continental slope failures may either increase (if triggered by shallow fault ruptures) or decrease ...