Articolele autorului Liviu Giosan
Link la profilul stiintific al lui Liviu Giosan

Evolution of Chilia lobes of the Danube delta: Reorganization of deltaic processes under cultural pressures

The growth of Chilia deltaic lobes reflects a drastic reorganization of the Danube delta that accompanied its rapid expansion in the late Holocene. Using new cores collected at the apices of the two older Chilia lobes, together with historical maps and satellite photos, we find that a partial avulsion since ∼1500 years BP led to a gradual rejuvenation of the Chilia distributary. This process led to the successive infilling of a lake and a lagoon

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Branched glycerol dialkyl glycerol tetraethers in Arctic lake sediments: Sources and implications for paleothermometry at high latitudes

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are analyzed in different lakes of the Mackenzie (Canadian Arctic) and Kolyma (Siberian Arctic) River basins to evaluate their sources and the implications for brGDGT-based paleothermometry in high latitude lakes. Comparison of brGDGT distributions and concentrations in the lakes with those in river suspended particulate matter (SPM), riverbank sediments, and permafrost material indicates that

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Varna Lake (north-eastern Bulgaria): vegetation history and human impact during the last 8000 years
Long-timescale variation in bulk and clay mineral composition of Indian continental margin sediments in the Bay of Bengal, Arabian Sea, and Andaman Sea

This study documents X-ray diffraction results from bulk powders and oriented clay-size aggregates using samples from sites drilled and cored during the Indian National Gas Hydrate Expedition 01 (NGHP01). These sites are located in the Krishna–Godavari Basin, Mahanadi Basin, and Andaman accretionary wedge of the Bay of Bengal, and the Kerala-Konkan Basin of the Arabian Sea. Calcite is more abundant at the pelagic sites of the Andaman Sea and Kerala-Konkan

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Sedimentation rates from calcareous nannofossil and planktonic foraminifera biostratigraphy in the Andaman Sea, northern Bay of Bengal, and eastern Arabian Sea

In this study we determined calcareous nannofossil and planktonic foraminifera events in sediments recovered during the 2006 Indian National Gas Hydrate Program (NGHP) Expedition-01. Selected bioevents permitted the assignment of orbitally calibrated ages, derivative sedimentation rate estimates, and identification of sedimentary discontinuities. In the Andaman Sea at Hole NGHP-01-17A, a late Miocene to recent record was recovered, but with a significant

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Anomalous porosity preservation and preferential accumulation of gas hydrate in the Andaman Accretionary Wedge, NGHP-01 Site 17A

In addition to well established properties that control the presence or absence of the hydrate stability zone, such as pressure, temperature, and salinity, additional parameters appear to influence the concentration of gas hydrate in host sediments. The stratigraphic record at Site 17A in the Andaman Sea, eastern Indian Ocean, illustrates the need to better understand the role pore-scale phenomena play in the distribution and presence of marine gas

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The role of North Brazil Current transport in the paleoclimate of the Brazilian Nordeste margin and paleoceanography of the western tropical Atlantic during the late Quaternary

Reconstructions of surface paleoceanographic conditions of the western equatorial Atlantic and past climates of the adjacent Northeast Brazilian (the "Nordeste") continental margin were undertaken by analyzing sediments from a piston core and associated gravity and box cores recovered from 3107 meter water depth at 0° 20’ N on the equatorial Brazilian continental slope. The record is dated by radiocarbon analysis and oxygen isotopic stratigraphy

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Sediment fluxes and buffering in the post-glacial Indus Basin

The Indus drainage has experienced major variations in climate since the Last Glacial Maximum (LGM) that have affected the volumes and compositions of the sediment reaching the ocean since that time. We here present a comprehensive first-order source-to-sink budget spanning the time since the LGM. We show that buffering of sediment in the floodplain accounts for ca. 20–25% of the mass flux. Sedimentation rates have varied greatly and must have

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Vegetation development in the central part of the Bulgarian Black Sea coast during the last 13 000 years
Using what we have: Optimizing sediment management in Mississippi River delta restoration to improve the economic viability of the nation

Management practices on the Mississippi River have reduced the amount of sediment in the river by approximately half. Some have questioned whether the current sediment load in the river is sufficient for restoration of the delta. The Mississippi River does not now, nor has it ever supplied enough sediment to continuously sustain the entire Mississippi Delta coastline. Nevertheless, the available sediment supply is still huge, and so we must use this

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