Article
Geography, Physical
Andrew M. W. Newton, Mads Huuse, David R. Cox, Paul C. Knutz
Summary: The Melville Bugt Trough Mouth Fan in offshore northwest Greenland is a common sedimentary feature that records the advance and retreat of ice sheets across the continental shelf since approximately 2.7 million years ago; the evolution of the continental shelf can be summarized into four stages, controlled by factors such as ice sheet erosion, topographic forcing of ice stream flow, and glacigenic deposition.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Jonathan L. Carrivick, Penelope How, James M. Lea, Jenna L. Sutherland, Michael Grimes, Fiona S. Tweed, Stephen Cornford, Duncan J. Quincey, Joseph Mallalieu
Summary: Ice-marginal lakes have a significant impact on glacier dynamics, but have been overlooked in studies on the Greenland ice sheet and peripheral glaciers. This study finds that lakes cover 10% of the Greenland ice margin and occur on 5% of peripheral glaciers. Ice velocity at lakes is around 25% higher than on land.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Jonathan L. Carrivick, Clare M. Boston, Jenna L. Sutherland, Danni Pearce, Hugo Armstrong, Anders Bjork, Kristian K. Kjeldsen, Jakob Abermann, Rachel P. Oien, Michael Grimes, William H. M. James, Mark W. Smith
Summary: Glaciers and ice caps (GICs) in Greenland have experienced significant fragmentation and mass loss since the Little Ice Age (LIA) termination in 1900. The number of glaciers has increased from 5327 to 5467, with at least 587 km(3) of ice lost from the ablation areas. The long-term mean mass balance has been estimated to be negative, and the rate of mass loss has increased threefold between 2000 and 2019. The spatial variability in glacier changes highlights the complex challenges in understanding regional and local factors affecting glacier evolution.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Hilde Oliver, Donald Slater, Dustin Carroll, Michael Wood, Mathieu Morlighem, Mark J. Hopwood
Summary: Subglacial discharge from Greenland's marine-terminating glaciers drives nutrient supply and stimulates phytoplankton growth. The nitrate fluxes are concentrated in a few critical systems, with 14% of glaciers accounting for half of the total flux anomaly. The largest flux occurs at Jakobshavn Isbr AE in Disko Bay, where subglacial discharge is highest. Subglacial discharge and nitrate flux anomaly also contribute to temporal variability in summer satellite chlorophyll a (Chl) near Greenland's coast.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Meghana Ranganathan, Jack-William Barotta, Colin R. Meyer, Brent Minchew
Summary: Liquid water within glacier ice and at the glacier beds plays a significant role in ice flow and stability. Meltwater from regions of rapid deformation, including shear margins, can affect the rheology of the ice and lubricate the bed. This study estimates the flux of meltwater from shear margins in three Antarctic regions and finds that it can be as significant as meltwater produced by frictional heating at the bed.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Geography, Physical
Joseph Mallalieu, Jonathan L. Carrivick, Duncan J. Quincey, Cassandra L. Raby
Summary: In southwest Greenland, there has been an extended and accelerating phase of ice-margin recession since 1992. Ice-marginal lakes exhibit significant correlations with rates of ice-margin recession, suggesting they play a key role in driving mass loss and ice-margin recession at the Greenland Ice Sheet. Further research is needed to understand the causal connections between ice-marginal lake evolution and enhanced ice-margin recession in order to accurately forecast the response of the ice sheet to changing environmental conditions.
GLOBAL AND PLANETARY CHANGE
(2021)
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
Geosciences, Multidisciplinary
Ian E. McDowell, Kaitlin M. Keegan, Nander Wever, Erich C. Osterberg, Robert L. Hawley, Hans-Peter Marshall
Summary: The relationship between firn microstructure and water movement is complex, as the microstructure controls the routing of meltwater and is continuously altered by liquid water flow. Microstructural transitions can stall vertical meltwater percolation, creating heterogeneities in water content and affecting firn metamorphism. Physics-based models aim to predict ice layer formation but require detailed observations to validate and inform percolation schemes.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geosciences, Multidisciplinary
Simona Caruso, Vittorio Maselli, Brice Rea, Matteo Spagnolo
Summary: This study presents an analysis of the seismic reflection dataset of the Foula wedge, revealing the complex depositional processes and geomorphic evolution of this sedimentary depocenter.
Article
Multidisciplinary Sciences
Stephan Krisch, Mark James Hopwood, Janin Schaffer, Ali Al-Hashem, Juan Hofer, Michiel M. Rutgers van der Loeff, Tim M. Conway, Brent A. Summers, Pablo Lodeiro, Indah Ardiningsih, Tim Steffens, Eric Pieter Achterberg
Summary: Approximately half of the freshwater discharged from the Greenland and Antarctic Ice Sheets enters the ocean subsurface, where it experiences prolonged residence times in large cavities beneath floating ice tongues. The subglacial dissolved Fe export from Nioghalvfjerdsbrae is decoupled from particulate inputs, likely due to the prolonged residence time of Atlantic water beneath Greenland's largest floating ice-tongue. These findings suggest that the overturning rate and particle-dissolved phase exchanges in ice cavities play a dominant role in controlling subglacial nutrient supply to shelf regions.
NATURE COMMUNICATIONS
(2021)
Article
Geosciences, Multidisciplinary
Kang Yang, Laurence C. Smith, Lauren C. Andrews, Xavier Fettweis, Manchun Li
Summary: There is a positive correlation between supraglacial drainage efficiency (D-d) and surface meltwater runoff (R) on the southwestern Greenland Ice Sheet. High-resolution satellite images can be used to map the spatial and temporal changes in D-d throughout the melt season, improving the characterization of supraglacial drainage efficiency.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Geosciences, Multidisciplinary
Michael J. MacFerrin, C. Max Stevens, Baptiste Vandecrux, Edwin D. Waddington, Waleed Abdalati
Summary: Assessing changes in snow and firn density is crucial for understanding mass changes on glaciers and ice sheets. This article presents a dataset that includes firn compaction measurements from different climate zones across the Greenland ice sheet, providing valuable validation for firn models.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Geography, Physical
Kristin Poinar, Lauren C. Andrews
Summary: This study used remote-sensing data to analyze the relationship between strain rates and lake drainages in western Greenland. The study found that moulins associated with fast-draining lakes have significantly higher extensional background strain rates. However, the current ice sheet velocity products cannot accurately resolve the transient strain rates that drive fast lake drainages.
Article
Geosciences, Multidisciplinary
Seth N. N. Goldstein, Jonathan C. C. Ryan, Penelope R. R. How, Sarah E. E. Esenther, Lincoln H. H. Pitcher, Adam L. L. LeWinter, Brandon T. T. Overstreet, Ethan D. D. Kyzivat, Jessica V. V. Fayne, Laurence C. C. Smith
Summary: Georectified time-lapse camera images accurately retrieve stage fluctuations of the proglacial Minturn River, enabling effective monitoring of meltwater runoff from the Greenland Ice Sheet. This non-contact approach provides a promising method for studying proglacial hydrological processes in harsh polar environments.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Multidisciplinary Sciences
Jennifer F. Arthur, Chris R. Stokes, Stewart S. R. Jamieson, J. Rachel Carr, Amber A. Leeson, Vincent Verjans
Summary: Observations of Antarctic supraglacial lakes (SGLs) are relatively scarce and their interannual variability is largely unknown. This study provides the first observations of SGLs across the entire East Antarctic Ice Sheet over multiple melt seasons. The results show that SGL volume varies greatly from year to year on some ice shelves, with more extensive and deeper lakes associated with higher summer air temperatures. Model predictions suggest that January melt and the ratio of November firn air content to summer melt are important predictors of SGL volume on vulnerable ice shelves.
NATURE COMMUNICATIONS
(2022)
Article
Geography, Physical
Riko Noormets, Anne Flink, Nina Kirchner
Summary: The study of submarine landforms and shallow sediment record in Hambergbukta reveals a complex and dynamic glacial history. The research suggests that the c. AD 1900 surge was less extensive than previously thought, and the retreat was likely rapid after the surges in c. AD 1900 and 1957.
Article
Multidisciplinary Sciences
Julia Steinbach, Henry Holmstrand, Kseniia Shcherbakova, Denis Kosmach, Volker Bruchert, Natalia Shakhova, Anatoly Salyuk, Celia J. Sapart, Denis Chernykh, Riko Noormets, Igor Semiletov, Orjan Gustafsson
Summary: The study investigates the sources of methane release in the East Siberian Arctic Shelf, indicating a significant contribution from submerged carbon and methane. Methane concentrations in the Laptev Sea showed large fluctuations and isotopic composition suggested a thermogenic/natural gas source in two seepage areas, with methane oxidation occurring further from the seeps. This knowledge is crucial for predicting future methane emissions in the region.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geosciences, Multidisciplinary
K. A. Hogan, N. S. Arnold, R. D. Larter, J. D. Kirkham, R. Noormets, C. O. Cofaigh, N. R. Golledge, J. A. Dowdeswell
Summary: The subglacial hydrological system plays a crucial role in the behavior of ice sheets, but is difficult to observe. This study combines investigations and modeling to reveal the accumulation, routing, and erosion potential of subglacial water over long timescales. The findings support previous theories and present a viable pattern for subglacial drainage.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Environmental Sciences
Christine L. Batchelor, Betina A. Frinault, Frazer D. W. Christie, Aleksandr Montelli, Julian A. Dowdeswell
Summary: This study discovered over 240 pockmarks using high-resolution geophysical data along the north-east Antarctic Peninsula margin. The existence of these pockmarks could have significant implications for benthic biodiversity and the global carbon cycle.
Article
Geosciences, Multidisciplinary
Frazer D. W. Christie, Toby J. Benham, Christine L. Batchelor, Wolfgang Rack, Aleksandr Montelli, Julian A. Dowdeswell
Summary: The study finds that 85% of the seaward ice-shelf perimeter along the 1400-km-long eastern Antarctic Peninsula has experienced continuous advance between the early 2000s and 2019, in contrast to the two previous decades. This advance is attributed to enhanced ocean-wave dampening, ice-shelf buttressing, and the absence of sea-surface slope-induced gravitational ice-shelf flow. These phenomena are enabled by increased near-shore sea ice driven by a Weddell Sea-wide intensification of cyclonic surface winds around 2002. The findings demonstrate that sea-ice change can either protect or trigger the final rift and calving of even large Antarctic ice shelves.
Article
Geosciences, Multidisciplinary
Christina S. Larkin, Mohamed M. Ezat, Natalie L. Roberts, Henning A. Bauch, Robert F. Spielhagen, Riko Noormets, Leonid Polyak, Steven G. Moreton, Tine L. Rasmussen, Michael Sarnthein, Edward T. Tipper, Alex M. Piotrowski
Summary: Neodymium isotope records reveal significant changes in deep-water formation and ocean circulation in the Nordic Seas and Arctic Ocean over the past 350,000 years. Deep-water formation was vigorous during the last glacial maximum but declined during deglaciation.
Article
Multidisciplinary Sciences
William Kochtitzky, Luke Copland, Wesley Van Wychen, Romain Hugonnet, Regine Hock, Julian A. Dowdeswell, Toby Benham, Tazio Strozzi, Andrey Glazovsky, Ivan Lavrentiev, David R. Rounce, Romain Millan, Alison Cook, Abigail Dalton, Hester Jiskoot, Jade Cooley, Jacek Jania, Francisco Navarro
Summary: This study estimated the frontal ablation of marine-terminating glaciers in the Northern Hemisphere and found that these glaciers contributed an average of 44.47 to 51.98 Gt of ice to the ocean annually from 2000 to 2020, making a significant contribution to sea-level rise.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Christine L. Batchelor, Frazer D. W. Christie, Dag Ottesen, Aleksandr Montelli, Jeffrey Evans, Evelyn K. Dowdeswell, Lilja R. Bjarnadottir, Julian A. Dowdeswell
Summary: Rates of ice-sheet grounding-line retreat can be measured from the spacing of corrugation ridges on the seafloor, providing context for ice-sheet change. However, limited examples restrict our understanding of future retreat rates and sea-level rise.
Article
Geochemistry & Geophysics
Brendan T. Reilly, Joseph S. Stoner, Saedis Olafsdottir, Anne Jennings, Robert Hatfield, Greta Bjork Kristjansdottir, Aslaug Geirsdottir
Summary: We investigated the amplitude and frequency of geomagnetic change in the Northern North Atlantic region over the past 15 thousand years. Using high-resolution sediment cores, we validated prior results and provided stronger geochronological constraints on the paleomagnetic secular variation signal. Our study also revealed greater variability and higher amplitudes on centennial timescales, which is important for understanding the geodynamo.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geography, Physical
Kelly A. Hogan, Katarzyna L. P. Warburton, Alastair G. C. Graham, Jerome A. Neufeld, Duncan R. Hewitt, Julian A. Dowdeswell, Robert D. Larter
Summary: Improvements in sea-floor mapping techniques have revealed regular ridge landforms formed by the tidal flexure of ice-shelf grounding lines. Mathematical models based on sea-floor observations suggest that either till extrusion or resuspension and transport of grains contribute to the formation of these ridges. The simulations indicate that grounding line retreat rates may be even higher than previously thought, as overprinting of ridges occurs when realistic bed slopes are considered.
Article
Ecology
David J. Harning, Brooke Holman, Lineke Woelders, Anne E. Jennings, Julio Sepulveda
Summary: The North Water Polynya (NOW) in Baffin Bay is a highly productive region and a crucial moisture source for local ice sheet sustenance. This study analyzed lipid biomarkers in modern surface sediment samples to better understand the functionality of paleoceanographic proxies. The results show strong correlations between highly branched isoprenoids and a higher concentration of sterols in the NOW, providing new insight into past development and downcore reconstructions.
Article
Geochemistry & Geophysics
W. A. P. Smith, P. Lewinska, M. A. Cooper, E. R. Hancock, J. A. Dowdeswell, D. M. Rippin
Summary: This paper studies the problem of structure-from-motion for images with varying principal point. Initialization and pose estimation methods specific to this scenario are proposed and the performance is demonstrated on challenging real-world examples.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Geography, Physical
Michael A. Cooper, Paulina Lewinska, William A. P. Smith, Edwin R. Hancock, Julian A. Dowdeswell, David M. Rippin
Summary: This study presents an approach to extract quantifiable information from archival aerial photographs to extend the record of change in central eastern Greenland Ice Sheet. The insights gained from a longer record of ice margin change are crucial for understanding glacier response to climate change. The study also focuses on relatively small and understudied outlet glaciers from the eastern margin of the ice sheet, revealing significant heterogeneity in their response with non-climatic controls playing a key role.
Article
Geography, Physical
Henrieka Detlef, Brendan Reilly, Anne Jennings, Mads Mork Jensen, Matt O'Regan, Marianne Glasius, Jesper Olsen, Martin Jakobsson, Christof Pearce
Summary: The study examines the Holocene sea ice dynamics in outer Petermann Fjord, suggesting a tight coupling between marine and terrestrial cryosphere in the region. The research also provides insights into the evolution of ice arches and landfast ice in Nares Strait during the Holocene period.