Geomorphological analysis on the Alentejo Margin: features and processes

Autor:	Teixeira, Manuel, Rodrigues, Sara, Roque, Cristina, Terrinha, Pedro, Ercilla, Gemma, Casas, David
Přispěvatelé:	Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Economía y Competitividad (España), British Petroleum, Instituto Dom Luiz, University of London, Sociedad Geológica de España
Rok vydání:	2018
Předmět:	landslide margen continental slope instability Geomorphological features Contourite features Along-slope processes Alentejo congreso contourite feature Slope instability Gravity-driven processes geomorphological feature Landslides gravity-driven process along-slope process
Zdroj:	Digital.CSIC. Repositorio Institucional del CSIC instname Digital.CSIC: Repositorio Institucional del CSIC Consejo Superior de Investigaciones Científicas (CSIC)
Popis:	Simposio sobre el Margen Ibérico Atlántico (9º. 2018. Coimbra, Portugal) The Alentejo Margin is a geomorphological complex area, where the interaction of bottom-currents with the irregular seafloor and gravitational processes creates a set of different along-slope and downslope-driven sedimentary features, such as drifts, moats, sediment waves, gullies and landslides scars and debris flow deposits. These features have been identified through the analysis of multibeam bathymetry and multichannel seismic data. Several landslide scars appear in the area, mostly in the western side of the contourite drift near the steep-slope Pereira de Sousa Fault scarp, with areas ranging from 0.15 to 40.3 km2, and volumes ranging from 0.01 to 6.34 km3. Thick debris flow deposits accumulate in the Lebre Basin (LB), downstream the scars, being fed by gullies coming from upstream with ~30 to ~120 m depth and ~2 km to ~20 km length. A ~2311-km2 contourite drift, with a ~84-km length moat, eastwards, is deposited by the Mediterranean Outflow Water (MOW), which creates sediment waves with varied extensions (~9 to 32 km) on this drift. The geomorphology of the Alentejo margin reflects a complex multi-process interaction, including bottom-current circulation, gravity-driven processes and tectonics. The interaction between these processes favoured active slope instability. Instituto Dom Luiz, Portugal Instituto Português do Mar e da Atmosfera, Portugal Estrutura de Missão para a Extensão da Plataforma Continental, Portugal Instituto de Ciencias del Mar, España Instituto Geológico y Minero de España, España
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::19a47d36d043d9a97fb19e0efc666aac http://hdl.handle.net/20.500.12468/1290 Zobrazit plný text záznamu