Search results for "Last Glacial Maximum"

Seismic stratigraphy of upper Quaternary shallow-water contourite drifts in the Gulf of Taranto (Ionian Sea, southern Italy)

2018

Abstract The occurrence of articulated seafloor morphology over continental shelf-upper slope environments, may result in a significant change in the patterns and intensity of basin-scale thermohaline circulation during eustatic sea-level fluctuations. These changes may cause, in turn, erosion, deposition and/or transport of sediments at the seafloor, to form shallow-water contourite drifts. Here we investigate this process in the NW sector of the Gulf of Taranto (Ionian Sea) during and following the Last Glacial Maximum (LGM), by integrating multibeam bathymetric data, ultra-high resolution seismic-reflection data and gravity core data. Sea level fall caused subaerial exposure of the summi…

MIS 5.5 highstand and future sea level flooding at 2100 and 2300 in tectonically stable areas of central mediterranean sea: Sardinia and the pontina …

2021

Areas of the Mediterranean Sea are dynamic habitats in which human activities have been conducted for centuries and which feature micro-tidal environments with about 0.40 m of range. For this reason, human settlements are still concentrated along a narrow coastline strip, where any change in the sea level and coastal dynamics may impact anthropic activities. We analyzed light detection and ranging (LiDAR) and Copernicus Earth observation data. The aim of this research is to provide estimates and detailed maps (in three coastal plain of Sardinia (Italy) and in the Pontina Plain (southern Latium, Italy) of: (i) the past marine transgression occurred during MIS 5.5 highstand 119 kyrss BP

How complex is the evolution of small mammal communities during the Late Glacial in southwest France?

2016

11 pages; International audience; The Late Glacial was a slow gradual warming associated with short, cold events that occurred between 18.0 and 11.7 ka cal. BP. Pollen analyses from deep-sea and lacustrine cores have well documented the evolution of floral communities in western Europe and suggest that climatic fluctuations influenced the evolution of terrestrial ecosystems. However, the exact impact of these climate changes on small faunal communities in southwest France is still poorly documented. Peyrazet Cave is an archaeological site located in the Lot (France) that has been excavated since 2008 and has yielded a Late Glacial sequence dated between 15.5 and 11.1 ka cal. BP. Thousands o…

Integrating species distribution models (SDMs) and phylogeography for two species of AlpinePrimula

2012

The major intention of the present study was to investigate whether an approach combining the use of niche-based palaeodistribution modeling and phylo-geography would support or modify hypotheses about the Quaternary distributional history derived from phylogeographic methods alone. Our study system comprised two closely related species of Alpine Primula. We used species distribution models based on the extant distribution of the species and last glacial maximum (LGM) climate models to predict the distribution of the two species during the LGM. Phylogeographic data were generated using amplified fragment length polymorphisms (AFLPs). In Primula hirsuta, models of past distribution and phylo…

Tracking the ice: Subterranean harvestmen distribution matches ancient glacier margins

2019

Biogeographic studies often underline the role of glacial dynamism during Pleistocene (1.806-0.011 Mya) in shaping the distribution of subterranean species. Accordingly, it is presumed that present-day distribution of most specialized cold-adapted (cryophilic) cave-dwelling species should bear the signatures of past climatic events. To test this idea, we modelled the distribution of specialized cold-adapted subterranean alpine harvestmen (Arachnida: Opiliones: Ischyropsalididae: Ischyropsalis). We found that the distance from the glacier margins during Last Glacial Maximum (LGM; about 22,000 years ago) was the most important predictor of their present-day distribution. In particular, the pe…

2020

Abstract. A compilation of the published literature on dust content in terrestrial and marine sediment cores was synchronized with pollen data and speleothem growth phases on the Greenland Ice Core Chronology 2005 (GICC05) time axis. Aridity patterns for eight key areas of the global climate system have been reconstructed for the last 60 000 years. These records have different time resolutions and different dating methods, i.e. different types of stratigraphy. Nevertheless, all regions analysed in this study show humid conditions during early Marine Isotope Stage 3 (MIS3) and the early Holocene or deglaciation, but not always at the same time. Such discrepancies have been interpreted as reg…

Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

2023

Acknowledgements: The authors thank G. Marciani and O. Jöris for comments on archaeology; C. Jeong, M. Spyrou and K. Prüfer for comments on genetics; M. O’Reilly for graphical support for Fig. 5 and Extended Data Fig. 9; the entire IT and laboratory teams at the Department of Archaeogenetics of MPI-SHH for technical assistance; M. Meyer and S. Nagel for support with single-stranded library preparation; K. Post, P. van Es, J. Glimmerveen, M. Medendorp, M. Sier, S. Dikstra, M. Dikstra, R. van Eerden, D. Duineveld and A. Hoekman for providing access to human specimens from the North Sea (The Netherlands); M. D. Garralda and A. Estalrrich for providing access to human specimens from La Riera (S…

Seasonal changes in glacial polynya activity inferred from Weddell Sea varves

2013

Abstract. The Weddell Sea and the associated Filchner–Rønne Ice Shelf constitute key regions for global bottom-water production today. However, little is known about bottom-water production under different climate and ice-sheet conditions. Therefore, we studied core PS1795, which consists primarily of fine-grained siliciclastic varves that were deposited on contourite ridges in the southeastern Weddell Sea during the Last Glacial Maximum (LGM). We conducted high-resolution X-ray fluorescence (XRF) analysis and grain-size measurements with the RADIUS tool (Seelos and Sirocko, 2005) using thin sections to characterize the two seasonal components of the varves at sub-mm resolution to distingui…

Pattern and rate of post-20 ka verticaltectonic motion around Capo Vaticanopromontory (W Calabria, Italy) based onoffshore geomorphological indicators

2013

The magnitude and rate of Late Pleistocene – Holocene vertical tectonic movements offshore Capo Vaticano (western Calabria) have been quantified on the basis of the depths of infralittoral prograding wedges (IPWs) and associated abrasion platforms formed during the stillstand of the Last Glacial Maximum (LGM). These features were identified on high-resolution reflection seismic profiles acquired along the continental shelf and upper slope around the promontory. The pattern of vertical movements of the Capo Vaticano promontory is characterized by a marked asymmetry associated with a NE-directed tilt. Removal of the non tectonic component of vertical changes using an ice-volume equivalent eus…

Measuring magnitude and rate of vertical movements in the offshore Capo Vaticano (W Calabria) using lowstand coastal prisms and wave-built terraces

2012

The magnitude and rate of vertical movements have been measured in the offshore Capo Vaticano (western Calabria) for the Late Pleistocene - Holocene on the basis of the depth of submerged coastal prism and associated wave-built terrace formed during the sea-level lowstand of the Last Glacial Maximum (LGM). Uplifted and submerged terraces have proved to be valuable recorders of vertical motion in many locations around the world (e.g. DICKINSON, 2001; WEBSTER et alii, 2004) as the depth of their tops appear to be controlled by the sea-level. In the eastern Tyrrhenian margins, depending on the hydraulic energy conditions (i.e. waves and wind-induced currents), the average water depth of terrac…