Abrupt changes in high-latitude nutrient supply to the Atlantic during the last glacial cycle

Geology ◽  
2012 ◽  
Vol 40 (2) ◽  
pp. 123-126 ◽  
Author(s):  
K.R. Hendry ◽  
L.F. Robinson ◽  
M.P. Meredith ◽  
S. Mulitza ◽  
C.M. Chiessi ◽  
...  
Keyword(s):  
High Latitude ◽  
Nutrient Supply ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Abrupt Changes ◽  
The Last Glacial

Effects of glaciation on karst hydrology and sedimentology during the Last Glacial Cycle: The case of Granito cave, Central Pyrenees (Spain)

CATENA ◽  
2021 ◽  
Vol 206 ◽  
pp. 105252
Author(s):  
Miguel Bartolomé ◽  
Carlos Sancho ◽  
Gerardo Benito ◽  
Alicia Medialdea ◽  
Mikel Calle ◽  
...  
Keyword(s):  
Karst Hydrology ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Central Pyrenees ◽  
The Last Glacial

scholarly journals Drivers of river reactivation in North Africa during the last glacial cycle

2021 ◽  
Vol 14 (2) ◽  
pp. 97-103
Author(s):  
Cécile L. Blanchet ◽  
Anne H. Osborne ◽  
Rik Tjallingii ◽  
Werner Ehrmann ◽  
Tobias Friedrich ◽  
...  
Keyword(s):  
North Africa ◽  
Glacial Cycle ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle

2018 ◽  
Vol 14 (11) ◽  
pp. 1819-1850 ◽  
Author(s):  
Olivier Cartapanis ◽  
Eric D. Galbraith ◽  
Daniele Bianchi ◽  
Samuel L. Jaccard
Keyword(s):  
Marine Sediments ◽  
Active Carbon ◽  
Deep Sea ◽  
Dissolved Inorganic Carbon ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Carbon Burial ◽  
Order Constraint ◽  
The Last Glacial ◽  
Carbon Inventory

Abstract. Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the “active” carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual buildup of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the δ13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity concentrations of the ocean by more than 100 µM, confirming that carbon burial fluxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1 PgC yr−1 prior to the rapid input of carbon during the industrial period.

scholarly journals Investigating the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle

2009 ◽  
Vol 5 (3) ◽  
pp. 329-345 ◽  
Author(s):  
S. Bonelli ◽  
S. Charbit ◽  
M. Kageyama ◽  
M.-N. Woillez ◽  
G. Ramstein ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Climate Model ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Atmospheric Co2 Concentration ◽  
The Last Glacial

Abstract. A 2.5-dimensional climate model of intermediate complexity, CLIMBER-2, fully coupled with the GREMLINS 3-D thermo-mechanical ice sheet model is used to simulate the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle and to investigate the ice sheets responses to both insolation and atmospheric CO2 concentration. This model reproduces the main phases of advance and retreat of Northern Hemisphere ice sheets during the last glacial cycle, although the amplitude of these variations is less pronounced than those based on sea level reconstructions. At the last glacial maximum, the simulated ice volume is 52.5×1015 m3 and the spatial distribution of both the American and Eurasian ice complexes is in reasonable agreement with observations, with the exception of the marine parts of these former ice sheets. A set of sensitivity studies has also been performed to assess the sensitivity of the Northern Hemisphere ice sheets to both insolation and atmospheric CO2. Our results suggest that the decrease of summer insolation is the main factor responsible for the early build up of the North American ice sheet around 120 kyr BP, in agreement with benthic foraminifera δ18O signals. In contrast, low insolation and low atmospheric CO2 concentration are both necessary to trigger a long-lasting glaciation over Eurasia.

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