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DC Field | Value | Language |
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dc.contributor.author | Rebesco, Michele | - |
dc.contributor.author | Camerlenghi, Angelo | - |
dc.contributor.author | Munari, Vanni | - |
dc.contributor.author | Mosetti, Renzo | - |
dc.contributor.author | Ford, Jonathan | - |
dc.contributor.author | Micallef, Aaron | - |
dc.contributor.author | Facchin, Lorenzo | - |
dc.date.accessioned | 2022-01-18T08:48:55Z | - |
dc.date.available | 2022-01-18T08:48:55Z | - |
dc.date.issued | 2021 | - |
dc.identifier.citation | Rebesco, M., Camerlenghi, A., Munari, V., Mosetti, R., Ford, J., Micallef, A., & Facchin, L. (2021). Bottom current-controlled quaternary sedimentation at the foot of the Malta Escarpment (Ionian Basin, Mediterranean). Marine Geology, 441, 106596. | en_GB |
dc.identifier.uri | https://www.um.edu.mt/library/oar/handle/123456789/87134 | - |
dc.description.abstract | A better understanding of the evolution of bottom current circulation and associated deposits is significant for many applications including paleoclimatology and geological hazard. Besides the large contourite drifts, bottom currents may generate fields of large sediment waves that, depending on their height and velocity of migration, may pose severe risk for infrastructures. Conversely, the time span of their paleoceanographic record is generally relatively short. We use bathymetry data, sub-bottom and seismic reflection profiles and legacy oceanographic data to analyze the sediment waves occurring in a deep environment (from 2400 to 3800 m water depth at the foot of the Malta Escarpment in the Mediterranean Sea) to understand their evolution in time, their significance for paleoceanography, and their relation to present day hydrographic conditions. In the absence of direct stratigraphic information, we use the information from nearby studies and from ODP Site 964 and DSDP Site 374 to constrain the age of the sedimentary successions. We discover that these waves (about 2.5 km in wavelength, 50 m in height, with crest sub-perpendicular to the continental slope trend) have been steadily growing and migrating northward since about 500 ka, although an irregular growth and unsteady migration is distinguishable since about 1800 ka. The waves are generated by predominantly alongslope southward flowing bottom currents compatible with modern hydraulic conditions (mean flow speed of ~5 cm s−1, peaks of 15 cm s−1). The rate of crest migration (~ 2.0–3.2 mm a−1) and the average sedimentation rate (0.64–0.69 mm a−1) are unusually high for deep sea environments away from turbidity currents paths. We infer that the steady development of sediment waves is produced by a drastic increase in sediment input to the Ionian Basin resulting from the tectonic uplift in NE Sicily and Calabria and the onset of a relatively steady, low energy bottom current regime following the Mid-Pleistocene Transition. We attempt to extract information on orbital cyclicity preserved in the seismic record from the power spectra of virtual seismic traces from the well preserved succession of 5 visually discernible, regularly spaced sub-units consisting of alternation of high-amplitude and low-reflectivity packages within the last 500 ka. Peaks in the power spectra can be identified around orbital obliquity and precession periodicities, while eccentricity appears not to be recorded. We discuss the results of seismic cyclicity analysis relative to uncertainties of stratigraphic and petrophysical constraints. The sediment waves along the foot of the Malta escarpment are an excellent candidate for the extraction of a long, continuous and high resolution sedimentary record of the paleo circulation changes and climate cycles in the Mediterranean Sea since about 500 ka. | en_GB |
dc.language.iso | en | en_GB |
dc.publisher | Elsevier | en_GB |
dc.rights | info:eu-repo/semantics/openAccess | en_GB |
dc.subject | Sedimentary basins -- Mediterranean Region | en_GB |
dc.subject | Seismites -- Mediterranean Region | en_GB |
dc.subject | Marine geophysics -- Mediterranean Region | en_GB |
dc.subject | Oceanography -- Mediterranean Region | en_GB |
dc.title | Bottom current-controlled quaternary sedimentation at the foot of the Malta Escarpment (Ionian Basin, Mediterranean) | en_GB |
dc.type | article | en_GB |
dc.rights.holder | The copyright of this work belongs to the author(s)/publisher. The rights of this work are as defined by the appropriate Copyright Legislation or as modified by any successive legislation. Users may access this work and can make use of the information contained in accordance with the Copyright Legislation provided that the author must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the prior permission of the copyright holder. | en_GB |
dc.description.reviewed | peer-reviewed | en_GB |
dc.identifier.doi | 10.1016/j.margeo.2021.106596 | - |
dc.publication.title | Marine Geology | en_GB |
Appears in Collections: | Scholarly Works - FacSciGeo |
Files in This Item:
File | Description | Size | Format | |
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Bottom current-controlled quaternary sedimentation at the foot of the Malta Escarpment.pdf | 29.53 MB | Adobe PDF | View/Open |
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