|
|
|
|
|
| Davies, Siwan M.; Abbott, Peter M.; Meara, Rhian H.; Pearce, Nicholas J. G.; Austin, William E. N.; Chapman, Mark R.; Svensson, Anders; Bigler, Matthias; Rasmussen, Tine L.; Rasmussen, Sune O.; Farmer, Elizabeth J.. |
| Building chronological frameworks for proxy sequences spanning 130-60 ka b2k is plagued by difficulties and uncertainties. Recent developments in the North Atlantic region, however, affirm the potential offered by tephrochronology and specifically the search for cryptotephra. Here we review the potential offered by tephrostratigraphy for sequences spanning 130-60 ka b2k. We combine newly identified cryptotephra deposits from the NGRIP ice-core and a marine core from the Iceland Basin with previously published data from the ice and marine realms to construct the first tephrostratigraphical framework for this time-interval. Forty-three tephra or cryptotephra deposits are incorporated into this framework; twenty three tephra deposits are found in the... |
| Tipo: Text |
Palavras-chave: Tephra; Cryptotephra; Tephrostratigraphy; Greenland ice-cores; North Atlantic marine cores; Iceland; Tephra correlations; Glass-shard analysis; Rapid climate changes. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40029/39255.pdf |
| |
|
|
| Rasmussen, Tine L.; Thomsen, Erik. |
| The last deglaciation, 20,000–10,000 years ago, was a period of global warming and rapidly shrinking ice sheets. It was also climatically unstable and retreats were interrupted by re-advances. Retreat rates and timing relative to climatic changes have therefore been difficult to establish. We here study a suite of 12 marine sediment cores from Storfjorden and Storfjorden Trough, Svalbard. The purpose is to reconstruct retreat patterns and retreat rates of a high northern latitude marine-based ice stream from the Svalbard-Barents Sea Ice Sheet in relation to paleoceanographic and paleoclimatic changes. The study is based on abundance and composition of planktic and benthic foraminiferal assemblages, ice rafted debris (IRD), lithology, and 70 AMS-14C dates.... |
| Tipo: Text |
Palavras-chave: Ice retreat rates; Storfjorden ice stream; Paleoceanography; Paleoclimate; Paleotemperature. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00658/77019/78289.pdf |
| |
|
|
| Capron, Emilie; Govin, Aline; Stone, Emma J.; Masson-delmotte, Valerie; Mulitza, Stefan; Otto-bliesner, Bette; Rasmussen, Tine L.; Sime, Louise C.; Waelbroeck, Claire; Wolff, Eric W.. |
| The Last Interglacial (LIG, 129-116 thousand of years BP, ka) represents a test bed for climate model feedbacks in warmer-than-present high latitude regions. However, mainly because aligning different palaeoclimatic archives and from different parts of the world is not trivial, a spatio-temporal picture of LIG temperature changes is difficult to obtain. Here, we have selected 47 polar ice core and sub-polar marine sediment records and developed a strategy to align them onto the recent AICC2012 ice core chronology. We provide the first compilation of high-latitude temperature changes across the LIG associated with a coherent temporal framework built between ice core and marine sediment records. Our new data synthesis highlights non-synchronous maximum... |
| Tipo: Text |
Palavras-chave: Last Interglacial period; Marine sediment cores; Ice cores; Data synthesis; Climate model simulations. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40063/39166.pdf |
| |
|
|
| Hoff, Ulrike; Rasmussen, Tine L.; Stein, Ruediger; Ezat, Mohamed M.; Fahl, Kirsten. |
| In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold... |
| Tipo: Text |
|
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00496/60722/65265.pdf |
| |
|
|
| Griggs, Adam J.; Davies, Siwan M.; Abbott, Peter M.; Rasmussen, Tine L.; Palmer, Adrian P.. |
| Tephrochronology is central to the INTIMATE(1) goals for testing the degree of climatic synchroneity during abrupt climatic events that punctuated the last glacial period. Since their identification in North Atlantic marine sequences, the Faroe Marine Ash Zone II (FMAZ II), FMAZ III and FMAZ IV have received considerable attention due to their potential for high-precision synchronisation with the Greenland ice-cores. In order to optimise the use of these horizons as isochronous markers, a detailed re-investigation of their geochemical composition, sedimentology and the processes that deposited each ash zone is presented. Shard concentration profiles, geochemical homogeneity and micro-sedimentological structures are investigated for each ash zone preserved... |
| Tipo: Text |
Palavras-chave: North Atlantic; Tephra; Taphonomy; Synchronisation; Micromorphology. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00496/60734/65220.pdf |
| |
|
| |
|
|
|
