Article
Geography, Physical
Quentin Duboc, Patrick Lajeunesse, Guillaume St-Onge, Matthias Moros, Kerstin Perner
Summary: Constraining the final retreat of the Laurentide Ice Sheet is important for understanding the impacts of glacial retreat on landscapes, sedimentary processes, oceanography, and climate variations in Eastern North America. This paper investigates the deglacial sedimentary sequences from Nachvak and Saglek Fjords in Northern Labrador, revealing thick deglacial sequences and important mass-movement deposits. The results suggest that earthquakes, sediment export, and Labrador Sea waters influenced the deglacial and postglacial sedimentary dynamics of the fjords.
QUATERNARY SCIENCE REVIEWS
(2023)
Review
Geography, Physical
Nicolas E. Young, Jason P. Briner, Gifford H. Miller, Alia J. Lesnek, Sarah E. Crump, Simon L. Pendleton, Roseanne Schwartz, Joerg M. Schaefer
Summary: Beryllium-10 has become a primary cosmogenic nuclide for quantifying Earth-surface processes. By measuring Be-10 at a precision level of <= 2-3%, researchers can now compare Be-10-based records of glacier and ice-sheet change to independent records of climate variability. The Be-10 measurements over the last 10+ years have provided a detailed picture of ice-margin migration through the early Holocene, showing interruptions in deglaciation by ice-margin readvances or stillstands.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Multidisciplinary Sciences
Lars Max, Dirk Nuernberg, Cristiano M. Chiessi, Marlene M. Lenz, Stefan Mulitza
Summary: This study provides solid evidence for the rapid subsurface ocean warming preceding Heinrich Events in the subpolar Atlantic. The accumulation of ocean heat near the critical depth is identified as the trigger for the melting of marine-terminating portions of the Laurentide Ice Sheet. The study also suggests that weaker ocean circulation in the future may lead to accelerated interior-ocean warming, which is critical for the stability of modern Arctic glaciers and the freshwater budget of the North Atlantic.
NATURE COMMUNICATIONS
(2022)
Article
Geography, Physical
Anders E. Carlson, Alberto Reyes, Kaja Sillett, Klaus M. Wilcken, Dylan H. Rood
Summary: This study evaluated the behavior of the southwest Greenland ice sheet during the 8.2 ka cold event using new and existing glacial geological data. The research found that the southwest Greenland ice-sheet margin in the Kangerlussuaq region retreated 5-10 km during the 8.2 ka cold event.
QUATERNARY SCIENCE REVIEWS
(2021)
Review
Geosciences, Multidisciplinary
Jianghu Lan, Tianli Wang, Jibao Dong, Shugang Kang, Peng Cheng, Kang'en Zhou, Xingxing Liu, Yaqin Wang, Le Ma
Summary: This study reveals that the moisture conditions in northern Central Asia during the early Holocene were controlled by the position of the mid-latitude Westerlies, while persistent drought conditions during the middle Holocene were caused by the northward migration of these Westerlies. The recent southward movement has resulted in a relatively wetter Central Asia region.
EARTH-SCIENCE REVIEWS
(2021)
Article
Oceanography
D. G. Babb, S. Kirillov, R. J. Galley, F. Straneo, J. K. Ehn, S. E. L. Howell, M. Brady, N. A. Ridenour, D. G. Barber
Summary: Hudson Strait is the only part of the Canadian Arctic where winter shipping takes place, but little is known about the thickness and dynamics of the ice pack. Icebreakers often face besetting events during winter operations, which significantly slow down or immobilize vessels. By analyzing in situ observations of ice draft and drift collected from 2005 to 2009, this study provides insights into the processes that influence ice thickness and internal pressure within the unique winter shipping corridor.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
Hege Kilhavn, Isabelle Couchoud, Russell N. Drysdale, Carlos Rossi, John Hellstrom, Fabien Arnaud, Henri Wong
Summary: The 8.2 ka event is considered as the most significant climate anomaly of the Holocene. Through analyzing the speleothem record from El Soplao Cave in northern Spain, it is found that the event is synchronized with other archives in southwestern Europe. The event was triggered by a meltwater release to the North Atlantic and had impacts on the climate and circulation at that time.
CLIMATE OF THE PAST
(2022)
Article
Geography, Physical
Emma Ownsworth, David Selby, Jeremy Lloyd, Paul Knutz, Sonke Szidat, John Andrews, Colm O'Cofaigh
Summary: A new study investigates the sediment core from central Baffin Bay to reconstruct the ice sheet history and sediment fluxes. Two dominant sediment/discharge sources, detrital carbonate and radio-genic felsic, are identified. The study also provides updated age constraints and further supports the theory of an ice shelf in northern Baffin Bay.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geography, Physical
Pierre-Olivier Couette, Patrick Lajeunesse, Jean-Francois Ghienne, Boris Dorschel, Catalina Gebhardt, Dierk Hebbeln, Etienne Brouard
Summary: Multibeam bathymetric and seismostratigraphic data provide insights into the glacial landforms and depositional assemblages in the Clyde fjord-cross-shelf trough system. The maximal extent of the Laurentide Ice Sheet margin during the Last Glacial Maximum is identified, along with the patterns and controls on its subsequent retreat. The sediment cores and radiocarbon ages reveal the depositional processes and the episodic style of deglaciation in the early Holocene.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geography, Physical
G. A. Goss, A. D. Rooney
Summary: The reconstruction of Pleistocene glacial cycles through oxygen isotope records reveals significant changes in global climate and ice sheet size. The Mid-Pleistocene Transition (MPT) marks a major shift in global ice sheet behavior from symmetrical 41-thousand-year cycles to asymmetrical 100-thousand-year cycles. The causes of this transition, including cryosphere dynamics and changes in Earth's energy balance, are still debated. The Regolith Hypothesis suggests that fluctuations in the stability of the Laurentide Ice Sheet (LIS) during the MPT were driven by changes in the lithology of its subglacial substrate. In this study, variations in seawater osmium isotope values are used to empirically investigate this hypothesis, revealing a lithological shift beneath the LIS during the MPT and a significant impact on chemical weathering fluxes to the ocean.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geography, Physical
Graham Rush, Ed Garrett, Mark D. Bateman, Grant R. Bigg, Fiona D. Hibbert, David E. Smith, W. Roland Gehrels
Summary: This study presents new evidence about the 8.2 ka climate event based on a high-resolution relative sea-level record from Scotland. The results indicate a significant change in sea-level rise rates before the event, which is likely attributed to the partial melting of the Laurentide Ice Sheet and the collapse of the Hudson Bay Ice Saddle, leading to substantial freshwater input into the North Atlantic and a subsequent shift in the Atlantic Meridional Overturning Circulation.
QUATERNARY SCIENCE ADVANCES
(2023)
Article
Multidisciplinary Sciences
Asier Garcia-Escarzaga, Igor Gutierrez-Zugasti, Ana B. Marin-Arroyo, Ricardo Fernandes, Sara Nunez de la Fuente, David Cuenca-Solana, Eneko Iriarte, Carlos Simoes, Javier Martin-Chivelet, Manuel R. Gonzalez-Morales, Patrick Roberts
Summary: By reconstructing the δ18O values from the subfossil vegetation layer exploited by early human groups in El Mazo cave, southern Spain, we revealed the impact of changes in sea surface temperature during the 8.2 ka event on human exploitation of shellfish resources and their choice of Atlantic coastal areas as refugia during this cold event.
SCIENTIFIC REPORTS
(2022)
Article
Geography, Physical
Liming Ye, Xiaoguo Yu, Dong Xu, Weiguo Wang, Yeping Bian, Juan Xu, Linsen Dong, Rong Wang, Weiyan Zhang, Yanguang Liu, Lu Jin, Ying Yang
Summary: This study investigates the source, amount, and trajectory of icebergs in the western Arctic Ocean and their impact on Arctic ice sheet development and the Atlantic meridional overturning circulation (AMOC). The findings provide insights into the origins of icebergs in the North Atlantic Ocean and the mechanisms of AMOC instability, suggesting that the expansion of the East Siberian ice sheet may play a more significant role in triggering iceberg outbursts than the discharge of icebergs from the Laurentide ice sheet.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
Jinhwa Shin, Jinho Ahn, Jai Chowdhry Beeman, Hun-Gyu Lee, Jaemyeong Mango Seo, Edward J. Brook
Summary: A new high-resolution record of atmospheric CO2 from the Siple Dome ice core in Antarctica reveals natural CO2 variability on millennial timescales during the early Holocene (11.7-7.4 ka) under interglacial climate conditions. Atmospheric CO2 decreased by approximately 10 ppm between 11.3 and 7.3 ka, with local minima at 11.1, 10.1, 9.1, and 8.3 ka. These variations correlate with proxies for solar forcing and local climate in the southeast Atlantic polar front, eastern equatorial Pacific, and North Atlantic. Further measurements and modeling are needed to confirm these observations using higher-quality ice cores and carbon cycle models.
CLIMATE OF THE PAST
(2022)
Article
Geography, Physical
J. H. England, R. D. Coulthard, M. F. A. Furze, C. F. Dow
Summary: This study documents the deposition and chronological record of a massive ice shelf from the former Laurentide Ice Sheet. The ice shelf advanced and retreated over a span of about 400 years, and its catastrophic breakup coincided with rapid warming of the atmosphere and ocean. The findings suggest that current ice dynamics models may underestimate the sensitivity of similar margins in Antarctica to ongoing global warming, emphasizing the importance of this research for estimating future sea level rise.
QUATERNARY SCIENCE REVIEWS
(2022)