Sedimentary responses to the climate changes in the Bay of Bengal since the last glaciation

2020 ◽  
Author(s):  
Jingrui Li ◽  
Xuefa Shi
Keyword(s):  
Sea Level ◽  
Bay Of Bengal ◽  
Climate Changes ◽  
North Atlantic Ocean ◽  
Last Deglaciation ◽  
Nutrient Inputs ◽  
The Holocene ◽  
Terrigenous Input ◽  
Last Glaciation ◽  
Holocene Period

<p>A sedimentary multi-index comprehensive study on a gravity core collected from the central Bay of Bengal (BoB) was presented with an attempt to understand the sedimentary processes and their responses to climate changes since the last glaciation. The sea level is suggested to be responsible for significant distinction of the terrigenous input between the last glaciation and the Holocene period through the depositional center transition in the BoB at the glacial-interglacial scale. The monsoon controlled terrigenous input at precession-related scales since it showed similar patterns with solar radiation and precipitation before 18 ka. Terrigenous input responses to the climate changes in the north Atlantic Ocean during the last deglaciation and early Holocene suggested at millennial scales. The paleoproductivity in the central BoB was at a roughly equivalent level during the last glaciation and the Holocene period, as indicated by the authigenic element accumulation rates. Different terrestrial nutrient inputs and ocean surface stratifications related to the Indian Summer Monsoon (ISM) were suggested to be responsible for this pattern. This study provides a brief understanding of the sedimentary response to the climate and emphasizes the different roles of the sea level and ISM in the central BoB.</p>

scholarly journals Applicability and Variability of Chemical Weathering Indicators and Their Monsoon-Controlled Mechanisms in the Bay of Bengal

2021 ◽  
Vol 9 ◽  
Author(s):  
Jingrui Li ◽  
Shengfa Liu ◽  
Xuefa Shi ◽  
Hui Zhang ◽  
Peng Cao ◽  
...  
Keyword(s):  
Bay Of Bengal ◽  
Chemical Weathering ◽  
Regional Climate ◽  
Source Area ◽  
Temperature Record ◽  
Last Deglaciation ◽  
Climate Conditions ◽  
The Holocene ◽  
Precipitation And Temperature ◽  
Holocene Period

To help understanding the potential relationship between chemical weathering and Indian summer monsoon (ISM) since the last glacial period a gravity core (BoB-56) was retrieved from the central Bay of Bengal (BoB). The data of chemical weathering indexes (CIA, WIP, and αAlNa) used in this study showed general synchronicity with the regional monsoon precipitation and temperature record on precessional scale, indicating existence of control from the ISM on weathering. Corresponding to alteration of warm/cold period during the last deglaciation, obvious simultaneously alteration of higher/lower values of the chemical weathering and terrestrial input proxies’ record support our hypothesis that the ISM driving chemical weathering on the millennial scale. However, a contradiction occurred during the Holocene period, when the ISM precipitation and temperature rose to a higher level, while the alternative indexes unanimously reflected a weaker chemical weathering conditions. In this study, we discussed the applicability of chemical weathering indexes in the BoB during the Holocene period. Besides the possible weakened monsoon during 6–3 ka, recorded by the stalagmite δ18O and Sea Surface Temperature (SST) reconstruction results in the northeastern Indian Ocean, other factors were responsible for this phenomenon, including the grain size effect and distinction between the mountain high land and floodplain low land. The chemical weathering records, during the last glaciation, indicated the presence of control from the ISM on weathering at precessional and millennial scales. While, during the Holocene, they failed to reflect the actual chemical weathering dynamics of the source area. Indeed, a mixture of physical erosion and chemical weathering seems to be representative of the chemical weathering dynamics in the area. Our findings emphasized on the tight connections between the chemical weathering evolution and global-regional climate conditions around the BoB, implying possible ISM-controlled mechanisms during different time scales.

scholarly journals Impact of relative sea level and rapid climate changes on the architecture and lithofacies of the Holocene Rhone subaqueous delta (Western Mediterranean Sea)

2014 ◽  
Vol 305 ◽  
pp. 35-53 ◽  
Author(s):  
Anne-Sophie Fanget ◽  
Serge Berné ◽  
Gwénaël Jouet ◽  
Maria-Angela Bassetti ◽  
Bernard Dennielou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Climate Changes ◽  
Western Mediterranean ◽  
Relative Sea Level ◽  
The Holocene ◽  
Western Mediterranean Sea

Circumpolar Distribution of Holocene Marine Fossils in Antarctic Beaches

1992 ◽  
Vol 37 (2) ◽  
pp. 256-260 ◽  
Author(s):  
Paul Arthur Berkman
Keyword(s):  
Sea Level ◽  
Climate Changes ◽  
Ice Sheet ◽  
Ice Cores ◽  
Marine Species ◽  
The Holocene ◽  
Antarctic Lakes ◽  
Circumpolar Distribution ◽  
Antarctic Marine ◽  
Marine Fossils

AbstractThe composite frequency of radiocarbon ages for Holocene marine fossils from beaches around Antarctica is significantly different than random. Variations in the frequency of fossil ages coincide with the timing of Holocene climate changes inferred from Antarctic ice cores, sub-Antarctic lakes, polar and alpine moraines, and sea level. Extant Antarctic marine species that occur as fossils in beaches may reflect coastal meltwater impacts associated with ice sheet marginal fluctuations that were circumpolar during the Holocene.

The last deglaciation simulated with a coupled atmosphere/ocean/ice sheet/solid earth model

2021 ◽  
Author(s):  
Uwe Mikolajewicz ◽  
Olga Erokhina ◽  
Marie-Luise Kapsch ◽  
Clemens Schannwell ◽  
Florian Ziemen
Keyword(s):  
Deep Water ◽  
Climate Changes ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Earth Model ◽  
Last Deglaciation ◽  
The Holocene ◽  
Simulated Climate ◽  
The Last Deglaciation

<p>It is challenging to model the last deglaciation, as it is characterized by abrupt millennial scale climate events, such as ice-sheet surges, that are superimposed on long-term climate changes, such as a global warming and the decay of a substantial part of the glacial ice sheets. Within PMIP, several groups have simulated the last deglaciation with CMIP-type models prescribing ice sheets from reconstructions. Whereas this type of simulations accounts for the effects of ice-sheet changes including meltwater release on climate, the prescribed ice sheet evolution is typically not consistent with the simulated climate evolution. Here we present a set of deglacial simulations that include fully interactive ice sheets that respond to changes in the climate. The setup also allows for feedbacks between ice sheets and climate and , hence, allows for a more realistic representation of the mechanisms of the last deglaciation, as the simulated climate and ice sheet changes are fully consistent..</p><p>The model consists of the coarse resolution set-up of MPI-ESM coupled to the ice sheet model mPISM (Northern Hemisphere and Antarctica) and the solid earth model VILMA. The model includes interactive icebergs and an automated calculation of the land-sea mask and river routing directions. A set of synchronously coupled simulations were started from an asynchronously coupled spin-up at 26ky and integrated throughout the deglaciation into the Holocene. The only prescribed external forcing are atmospheric concentrations of greenhouse gases and earth orbital parameters. One goal of this ensemble was to find the optimal combination of model parameters for the simulation of the deglaciation.</p><p>The model simulates the decay of the ice sheets, the rise of sea level, the flooding of shelf seas and the opening of passages. A large fraction of the ice sheet retreat is due to dynamical events (e.g. the final decay of the ice sheets on Barents Shelf or the Hudson Bay). Superimposed on the relatively slow glacial/interglacial transition are abrupt climate changes, triggered for example by recurrent ice sheet surges. These surges correspond to Heinrich Events tand result in a weakening of the AMOC. Three source regions for ice sheet surges occur during these simulations: from the Laurentide ice sheet through Hudson Strait, from the Laurentide ice sheet northward directly to the Arctic ocean, and from the Fennoscandian ice sheet into the Norwegian Sea. The characteristic climate response shows a large dependence on the surge location.</p><p>The simulated changes in strength of the AMOC are except for millennial-scale reduction events only moderate. However, during glacial periods, brine release is the central process for deep water formation in both hemispheres, in contrast to the Holocene. dDuring the deglaciation the ventilation of the deep ocean is strongly reduced, leading to a strong increase of the simulated deep water ages. This effect lasts longest in the deep North Pacific and extends in some simulations into the Holocene.</p>

The Similarity of Malay Architecture Terminology: Perahu and House

2017 ◽  
Vol 14 (1) ◽  
pp. 33
Author(s):  
Mohamad Hanif Abdul Wahab ◽  
Azizi Bahauddin
Keyword(s):  
Literature Review ◽  
Sea Level ◽  
Housing Construction ◽  
Way Of Life ◽  
The Holocene ◽  
Review Analysis ◽  
Holocene Period

The perahu also known as boat was used by the Malay community during the Holocene period when the rise of the sea level altered the Malay world and it became islands and a peninsula. The perahu became important, not only as a navigational vessel but served as a shelter during the journey. As sailing is a part of Malay way of life, many perahu manifestations are often seen in housing construction. The objectives of this paper are to outline the features of perahu used around Negeri Sembilan traditional house – architecture with kajang perahu analogy – and to raise questions on what are the similarities between the terminology perahu and house. The questions look through literature review analysis and identify elements and components related to the house. Keywords: Malay, architecture, terminology, perahu, house

CORRELATION OF THE BLACK, MARMARA AND AEGEAN SEAS DURING THE HOLOCENE

2017 ◽  
Author(s):  
Nikolay Esin ◽  
Nikolay Esin ◽  
Vladimir Ocherednik ◽  
Vladimir Ocherednik
Keyword(s):  
Mathematical Model ◽  
Sea Level ◽  
Black Sea ◽  
Aegean Sea ◽  
The Black Sea ◽  
Sea Level Changes ◽  
The Holocene

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.

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