Stratigraphical evidence of Late Holocene barrier breaching and extreme storms in lagoonal sediments of Ria Formosa, Algarve, Portugal

Andrade, César; Freitas, Maria Conceição; Moreno, João; Craveiro, S.C.

doi:10.1016/j.margeo.2004.05.016

Cited by 85 publications

(52 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The average precipitation in this zone for the last 75 years is 530 mm yr À1 and is concentrated between October and April. At present, the estuarine zone is sheltered behind the Cabanas Island from the Ria Formosa Barrier Island system that was initiated in the early Holocene (Andrade et al, 2004). At the second site, 20 km eastward, the Beliche River drains a basin of about 125 km 2 , which is placed exclusively on Carboniferous shales and greywackes.…”

Section: The Study Areamentioning

confidence: 99%

Chronology of the sedimentary processes during the postglacial sea level rise in two estuaries of the Algarve coast, Southern Portugal

Boski

Camacho

Moura

et al. 2008

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

Section: The Study Areamentioning

confidence: 99%

Chronology of the sedimentary processes during the postglacial sea level rise in two estuaries of the Algarve coast, Southern Portugal

Boski

Camacho

Moura

et al. 2008

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

“…There is no information on the Larache coast of Morocco, but it is also exposed to WNW and in consequence, is probably acted by a wave regime with intensity not much lower than the ones of the western coast of Portugal. At the sheltered, southwest facing AP coast, the wave energy input drops by an order of magnitude, and the southern coast of Algarve is acted by storms from SW and SE, and a medium energy wave regime (Andrade et al, 2004).…”

Section: F M S F Marques: Magnitude-frequency Of Sea Cliff Instabmentioning

confidence: 99%

Magnitude-frequency of sea cliff instabilities

Marques

2008

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. The magnitude-frequency relationship of sea cliff failures in strong, low retreat rate cliffs, was studied using systematic historical inventories carried out in the coasts of Portugal and Morocco, in different geological and geomorphological settings, covering a wide size scale, from small to comparatively large rockslides, topples and rockfalls, at different time and spatial scales. The magnitude-frequency expressed in terms of volume displaced and of horizontal area lost at the cliff top showed good fit by inverse power laws of the type p=a.x −b , with a values from 0.2 to 0.3, and exponents b close to 1.0, similar to those proposed for rockfall inventories. The proposed power laws address the magnitudefrequency for sea cliff failures, which is an important component of hazard assessment, to be completed with adequate models for space and time hazard components. Maximum local retreat at the cliff top provided acceptable fitting to inverse power laws only for failures wider than 2m, with a=4.0, and exponent b=2.3, which may be useful to assess the cliff retreat hazard for the use of areas located near the cliff top.

show abstract

“…The occurrence of sandy layers in the stratigraphic record of lakes and coastal areas is thus considered a proxy for past storminess (Andrade et al, 2004). Their formation and preservation is not common since it might depend on many factors, such as the disposability of sand from the coastal system, the burial rate, the bioturbation, the possible sand winnowing due to subsequent storm recurrence (Wheatcroft and Drake, 2003;Keen et al, 2004;Dawson et al, 2004a).…”

Section: Sea Storm Event Bedsmentioning

confidence: 99%

Sediment transport and deposition during extreme sea storm events at the Salerno Bay (Tyrrhenian Sea): comparison of field data with numerical model results

Budillon

Vicinanza²,

Ferrante³

et al. 2006

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Seismic stratigraphy and core litho-stratigraphy in the Salerno Bay inner shelf (Southern Tyrrhenian Sea) reveal significant storm deposition episodes over the last 1 ky. Three major events are preserved as decimetre thick silt/sand layers bounded at their base by erosional surfaces and sealed in the muddy marine sequences between 25 and 60 m of depth. Geochronology and chrono-stratigraphy on core sediment point towards a recurrence of major sea storms between 0.1 and 0.3 ky and put the last significant event in the 19th century, when no local meteorological time series is available. A modelling of extreme sea-storms with a return period of about 0.1 ky is here proposed based on historical hindcast and aims at explaining the occurrence of such unusual deep and thick sand deposits in the northern sector of the bay. Results highlight the vulnerability of the northern coast of the Salerno Bay to the south western sea storms which can drive waves up to about 8 m high and wave period of about 13 s. With these conditions an intense combined flow current is formed and might account for winnowing fine sand down to the depth of 40 m at least. The numerical model thus confirms a possible sand transport in the bottom boundary layer due to wave-current interaction and could corroborate the interpretation of the most recent sand layers, included in the cores, as being generated under extreme sea storm conditions.

show abstract

Stratigraphical evidence of Late Holocene barrier breaching and extreme storms in lagoonal sediments of Ria Formosa, Algarve, Portugal

Cited by 85 publications

References 13 publications

Chronology of the sedimentary processes during the postglacial sea level rise in two estuaries of the Algarve coast, Southern Portugal

Chronology of the sedimentary processes during the postglacial sea level rise in two estuaries of the Algarve coast, Southern Portugal

Magnitude-frequency of sea cliff instabilities

Sediment transport and deposition during extreme sea storm events at the Salerno Bay (Tyrrhenian Sea): comparison of field data with numerical model results

Contact Info

Product

Resources

About