Article
Geography, Physical
Dag Ottesen, Christine L. Batchelor, Lilja R. Bjarnadottir, Daniel Hesjedal Wiberg, Julian A. Dowdeswell
Summary: The analysis of glacial landforms on continental margins provides insights into sedimentation processes beneath ice sheets and aids predictions of future ice sheet resilience. This study used high-resolution marine-geophysical data to map and interpret glacial landforms along the mid-Norwegian margin, revealing the dynamic behavior of the Scandinavian Ice Sheet during the last glacial-interglacial cycle. The geometry of the continental shelf played a key role in controlling the pattern of ice-sheet retreat.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
C. M. Darvill, B. Menounos, B. M. Goehring, A. J. Lesnek
Summary: This study reports 20 Be-10 exposure ages from glacial erratics and bedrock on the west coast of British Columbia, Canada, contributing to the existing chronologies of Cordilleran Ice Sheet retreat along approximately 600 km of coastal North America. The data show that the western ice limit reached the present coast by 18-16 ka then slowed its retreat for around 4,000 years until 14-13 ka. The initial retreat is attributed to destabilization and grounding line retreat caused by rising sea level and/or ocean warming in the northern Pacific. Despite increasing temperatures, the subsequent stability of the ice sheet at the present coastal margin is likely due to the transition from marine to terrestrial margins.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geography, Physical
Qing Yan, Ting Wei, Zhongshi Zhang
Summary: Investigation of Patagonian glaciers during the Last Glacial Maximum (gLGM) reveals the sensitivity of these glaciers to climate change. The study shows that temperature and precipitation have significant impacts on the total glacier area and equilibrium-line altitude of Patagonian glaciers. The modeled ice sheet extent and flow pattern during the gLGM match well with empirical reconstructions.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Geography, Physical
Jing Lei, Zhengguo Shi, Xiaoning Xie, Xinzhou Li
Summary: Based on climate model experiments, this study found that the precipitation during the Last Glacial Maximum (LGM) was significantly different from that of the preindustrial period in the terrestrial monsoon regions and arid regions of the Northern Hemisphere. The decrease in sea surface temperature and expansion of the ice sheet were the main contributors to lessening precipitation in the monsoon regions, while the decrease in precipitation in the arid regions can be mainly attributed to ice-sheet-induced albedo and topography changes.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Asmita Banerjee, Laurence Y. Yeung, Lee T. Murray, Xin Tie, Jessica E. Tierney, Allegra N. Legrande
Summary: Ice cores and other paleotemperature proxies provide information about past surface temperatures, but little is known about high-altitude temperatures. This study uses the clumped-isotope composition of molecular oxygen in ice cores to infer that the upper troposphere was 6-9 degrees C cooler during the Last Glacial Maximum than during the late preindustrial Holocene.
Article
Geosciences, Multidisciplinary
S. Wetterich, H. Meyer, M. Fritz, G. Mollenhauer, J. Rethemeyer, A. Kizyakov, L. Schirrmeister, T. Opel
Summary: Stable isotopes of wedge ice can help reconstruct past winter climate conditions. Records from Bol'shoy Lyakhovsky Island show that the LGM and MIS 3 had colder winter climates, while the moisture sources were similar during MIS 2.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Ming Zhang, Yonggang Liu, Jiang Zhu, Zhuoqun Wang, Zhengyu Liu
Summary: In this study, we investigated the changes in climate and Atlantic Meridional Overturning Circulation (AMOC) during the Last Glacial Maximum if there were no dust. Model simulations showed that the removal of dust resulted in a global cooling and weakening of AMOC. This cooling effect was opposite to that observed during the mid-Holocene and was amplified by a positive feedback between sea ice and AMOC.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Zhiang Xie, Li Dong, Kaijun Liu
Summary: The study investigates the changes in tropospheric stratification during the Last Glacial Maximum (LGM) using numerical simulations. The results show a decrease in stability in the tropics and an increase in stability in the extratropics during certain seasons. The increased stability over high-latitude ocean is driven by shifts in surface frozen lines, while the stability over ice sheet margins is due to the cooling effect of ice sheet slopes.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geography, Physical
Helen E. Dulfer, Martin Margold, Christopher M. Darvill, Arjen P. Stroeven
Summary: The study investigates the dynamics of the Cordilleran Ice Sheet (CIS) in northern British Columbia, Canada during the Last Glacial Maximum (LGM) and its subsequent retreat. By analyzing glacial landforms, the research identifies three stages of ice flow and reveals complex changes in ice dynamics over time. The study also provides insights into the post-LGM ice retreat and the re-growth of independent mountain glaciers in the Late Glacial period.
QUATERNARY SCIENCE REVIEWS
(2022)
Review
Geography, Physical
Linda Pan, Glenn A. Milne, Konstantin Latychev, Samuel L. Goldberg, Jacqueline Austermann, Mark J. Hoggard, Jerry X. Mitrovica
Summary: This study investigates the impact of lateral variations in Earth structure on predicting far-field sea level and global ice volume estimates at the Last Glacial Maximum. The findings suggest that different Earth model parameters significantly affect the estimates at far-field sites, but no consistent signal is found to reconcile the differences in ice volume estimates.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Environmental Sciences
Stephen C. C. Dobbs, Charles K. K. Paull, Eve M. M. Lundsten, Roberto Gwiazda, David W. W. Caress, Mary McGann, Marianne M. M. Coholich, Maureen A. L. Walton, Nora M. M. Nieminski, Tim McHargue, Stephan A. A. Graham
Summary: A high-resolution multibeam survey in the San Simeon Channel identified recurring troughs and ridges adjacent to meander bends. Through an integrated study, it was concluded that turbidity current event frequency was higher in the late Pleistocene due to sea-level rise and sediment sequestration on the shelf during the Holocene. This study highlights the significant decrease in sediment gravity flows in the region compared to times of continental shelf subaerial exposure.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Ting Wang, Na Wang, Dabang Jiang
Summary: We investigate changes in the intertropical convergence zone (ITCZ) during the last glacial maximum (LGM) using multiple simulations. Most models show that the LGM ITCZ shifts southward, narrows, and weakens on a global scale. Regionally, the central and eastern Pacific show the largest position and intensity changes, while the Indian Ocean-western Pacific experience the most obvious width changes. The September-October-November and June-July-August seasons contribute the most to the annual ITCZ changes globally and in most regions.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geochemistry & Geophysics
Mohamed S. Elhebiry, Mohamed Sultan, Abotalib Z. Abotalib, Alan E. Kehew, Peter J. Voice, Ibrahim Abu El-Leil
Summary: This study provides evidence for a Late Ordovician glacial origin of streamlined landforms in Arabia and reconstructs the Late Ordovician ice sheet. The results support the existence of a significant and dynamic ice sheet during the Late Ordovician period and provide new morphological constraints for paleo-climate models.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
J. M. Lora, C. B. Skinner, W. D. Rush, S. H. Baek
Summary: Proxy reconstructions and model simulations show that the hydroclimate during the Last Glacial Maximum was mainly influenced by ice sheets, causing reductions in moisture transport and precipitation globally, except for increases in precipitation over Patagonia, Iberia, and southwestern North America.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geography, Physical
Tancrede P. M. Leger, Andrew S. Hein, Robert G. Bingham, Angel Rodes, Derek Fabel, Rachel K. Smedley
Summary: The study reveals a detailed chronology of the Last Glacial Maximum expansions of the Rio Corcovado glacier in northern Patagonia, showing that the glacier's expansion was coeval with global Last Glacial Maximum and climatic signals, but out of phase with local summer insolation intensity. Additionally, it is observed that local ice sheet deglaciation occurred 1-2 ka earlier than other regions.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geochemistry & Geophysics
Julie Heggdal Velle, Maureen H. Walczak, Brendan Reilly, Guillaume St-Onge, Joseph S. Stoner, Stewart Fallon, Alan C. Mix, Christina Belanger, Matthias Forwick
Summary: The study investigated high-resolution paleomagnetic records of sediments from the south Alaska continental slope, suggesting that Site U1419 provides the ability to study paleomagnetic secular variation. Due to various factors, sediments at this site are not suitable for paleointensity studies, but the inclination record is deemed reliable to some extent and offers insights into regional geomagnetic variations.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Brandon Shuck, Sean P. S. Gulick, Harm J. A. Van Avendonk, Michael Gurnis, Rupert Sutherland, Joann Stock, Erin Hightower
Summary: This study reveals the spatial-temporal evolution of stress during subduction initiation and suggests an accelerated transition to self-sustaining subduction. In contrast to previous hypotheses, the study proposes a four-dimensional evolution where horizontal forces initially dominate but vertical forces accelerate over time and facilitate the development of self-sustaining subduction.
Article
Geosciences, Multidisciplinary
Maureen A. L. Walton, Sean P. S. Gulick, Peter J. Haeussler
Summary: This study presents an improved tectonic framework for the Yakutat area in southeastern Alaska, based on marine geophysical data collected in 2012. By combining various data sources, the researchers were able to update the fault map, develop a structural model of Yakutat Bay, and assess the uncertainties of previous geologic coseismic uplift measurements. The results provide valuable insights into earthquake hazards in the region.
Article
Multidisciplinary Sciences
Francisco J. Rodriguez-Tovar, Pim Kaskes, Jens Ormo, Sean P. S. Gulick, Michael T. Whalen, Heather L. Jones, Christopher M. Lowery, Timothy J. Bralower, Jan Smit, David T. King, Steven Goderis, Philippe Claeys
Summary: Researchers have reconstructed the macrobenthic tracemaker community and marine paleoenvironment in the Chicxulub impact area prior to the large impact event using paleoichnology and micropaleontology. The study shows that the K-Pg impact event did not have significant effects on the composition of the macroinvertebrate tracemaker community in the Chicxulub region.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Uisdean Nicholson, Veronica J. Bray, Sean P. S. Gulick, Benedict Aduomahor
Summary: Evidence of marine target impacts is rare on Earth. Seismic reflection data from the Guinea Plateau suggest the presence of a complex impact crater that formed approximately 66 million years ago, similar to the age of the Chicxulub impact crater. The crater may have formed as part of a closely timed impact cluster or through the breakup of a common parent asteroid.
Article
Geology
Cole M. Speed, John M. Swartz, Sean P. S. Gulick, John A. Goff
Summary: This study reveals the preservation and stratigraphic expression of coastal geomorphic features through the analysis of seismic reflection data. It also proposes recognition criteria for the seismic stratigraphic expression of coastal floodplain channels.
Article
Geochemistry & Geophysics
Sietze J. de Graaff, Catherine H. Ross, Jean-Guillaume Feignon, Pim Kaskes, Sean P. S. Gulick, Steven Goderis, Thomas Dehais, Vinciane Debaille, Ludovic Ferriere, Christian Koeberl, Nadine Mattielli, Daniel F. Stockli, Philippe Claeys
Summary: The study presents the first ages of pre-impact magmatic dikes preserved in Chicxulub's peak ring, providing insights into the subsurface composition and evolutionary history of the Yucatan Peninsula. The dating results reveal two age groups, Carboniferous dacites (328-318 Ma) and Jurassic dolerites (169-159 Ma), suggesting the presence of previously unsampled magmatic phases. The investigation of isotopic compositions further indicates that the dolerites contributed significantly to the Chicxulub impact melt rock, representing a pervasive Jurassic magmatic phase associated with the opening of the Gulf of Mexico.
Article
Geosciences, Multidisciplinary
Jacob T. Burstein, John A. Goff, Sean P. S. Gulick, Christopher Lowery, Patricia Standring, John Swartz
Summary: Understanding the role of antecedent topography in the evolution of barrier islands is valuable for preparing coastal communities for future impacts of climate change. This study investigates the stratigraphic framework of the Trinity River incised valley offshore Galveston, Texas to examine the influence of antecedent topography on the evolution of an early Holocene barrier island system. The findings highlight the central role of the geometry and elevation of the underlying antecedent topography in promoting both initiation and stabilization of the barrier island system.
Article
Geochemistry & Geophysics
Eduardo Q. Alves, Kita D. Macario, Rita Scheel-Ybert, Fabiana M. Oliveira, Andre Carlo Colonese, Paulo Cesar Fonseca Giannini, Renato Guimaraes, Stewart Fallon, Marcelo Muniz, David Chivall, Christopher Bronk Ramsey
Summary: This study investigates a Late Holocene shell mound in Southern Brazil using a multidisciplinary approach. The results reveal a negative local correction for the marine reservoir effect (MRE) in the area and a diet high in marine proteins for the inhabitants. The study also discusses various complications encountered when conducting MRE studies using shell mound sites.
Article
Geochemistry & Geophysics
R. E. Wood, R. Esmay, E. Usher, S. J. Fallon
Summary: The Single Stage AMS radiocarbon facility at the Australian National University has been in operation for 14 years. This paper discusses the pretreatment methods used for the different types of samples and examines the effectiveness of quality assurance protocols in detecting altered materials. Most of the fossil samples tested by the facility come from tropical and arid environments, where diagenesis of organic samples and carbonates is often severe. A significant proportion of the submitted samples cannot be dated, emphasizing the importance of screening and quality assurance methods. After analyzing 250 measurements on bone collagen, revised quality assurance indicators for bone samples are proposed.
Article
Geochemistry & Geophysics
Gail L. Christeson, Sean P. S. Gulick, Maureen A. L. Walton, Ginger A. Barth
Summary: This study investigates the crustal structure of the Gulf of Alaska Seamount Province and reveals that variations in crustal thickness and lithospheric thickness play a significant role in the magmatic underplating at seamounts and seamount provinces.
Article
Geochemistry & Geophysics
Christina M. Verhagen, Ji-In Jung, Sonia M. Tikoo, Axel Wittmann, David A. Kring, Stefanie Brachfeld, Laying Wu, Dale H. Burns, Sean P. S. Gulick
Summary: Using advanced microscopy techniques, this study investigated the nature and occurrence of primary and secondary Fe-oxide and Fe-sulfide minerals in the suevite of the Chicxulub impact crater. The results showed decomposition and dissolution patterns of large primary Fe-oxides and the presence of sub-micrometer Fe-oxide crystals concentrated within clay. Secondary Fe-sulfide minerals, associated with Ni- and Co-rich phases, were also found. These findings provide insights into hydrothermal trends and the remobilization of Fe and associated elements in suevites.
Article
Geosciences, Multidisciplinary
Maria-Elena Vorrath, Juliane Mueller, Paola Cardenas, Thomas Opel, Sebastian Mieruch, Oliver Esper, Lester Lembke-Jene, Johan Etourneau, Andrea Vieth-Hillebrand, Niko Lahajnar, Carina B. Lange, Amy Leventer, Dimitris Evangelinos, Carlota Escutia, Gesine Mollenhauer
Summary: The reconstruction of past sea-ice distribution in the Southern Ocean is crucial for understanding ice-ocean-atmosphere interactions and assessing Earth system and Antarctic ice sheet models. This study focused on the northern Antarctic Peninsula (NAP) and utilized marine sediment cores to reveal the long-term sea-ice history. Sea-ice biomarkers and diatom assemblages were used for reconstructions, while ocean temperatures were reconstructed using glycerol dialkyl glycerol tetraethers (GDGTs). The findings show varying sea-ice trends throughout different periods, with a maximum ice cover during the Antarctic Cold Reversal and decreasing ice cover during the Middle Holocene.
CLIMATE OF THE PAST
(2023)
Article
Archaeology
Keith C. Seramur, Kyle B. Campbell, Joseph B. Anderson, Ellen A. Cowan
Summary: Ground-penetrating radar (GPR) was used to map anomalies characteristic of unmarked graves on the grounds of Clemson University. The study revealed hundreds of organized unmarked graves believed to belong to African Americans. The research provides insights into the history of the cemetery and the need to modify the current operating protocol.
ARCHAEOLOGICAL PROSPECTION
(2023)
Review
Geosciences, Multidisciplinary
Xavier Crosta, Karen E. Kohfeld, Helen C. Bostock, Matthew Chadwick, Alice Du Vivier, Oliver Esper, Johan Etourneau, Jacob Jones, Amy Leventer, Juliane Mueller, Rachael H. Rhodes, Claire S. Allen, Pooja Ghadi, Nele Lamping, Carina B. Lange, Kelly-Anne Lawler, David Lund, Alice Marzocchi, Katrin J. Meissner, Laurie Menviel, Abhilash Nair, Molly Patterson, Jennifer Pike, Joseph G. Prebble, Christina Riesselman, Henrik Sadatzki, Louise C. Sime, Sunil K. Shukla, Lena Thole, Maria-Elena Vorrath, Wenshen Xiao, Jiao Yang
Summary: Antarctic sea ice plays a critical role in the Earth system, but accurately simulating and projecting future changes in sea ice remains challenging. This paper reviews proxies and reconstructions of sea ice changes throughout the last glacial-interglacial cycle. Diatom fossil assemblages and HBI alkenes in marine sediments, along with chemical proxies in Antarctic ice cores, are commonly used for Antarctic sea ice reconstructions. The reconstructions suggest that sea ice cover during the Last Glacial Maximum was much larger than today, and efforts have also been made to study sea ice during warm periods as an analogue for the future. Limited proxy records covering the complete glacial cycle highlight the need for additional research to better understand the drivers and feedbacks of Antarctic sea ice changes over the past 130,000 years.
CLIMATE OF THE PAST
(2022)