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1. Geology of West Antarctica

   Siddoway, Christine Smith (January 2021, Beiträge zur regionalen Geologie der Erde)

   Kleinschmidt, Georg (Ed.)

   The work is Chapter Three in a volume that provides a comprehensive overview of the geology of the Antarctic continent. The book represents the first comprehensive update of Antarctic geology in 25 years or more. Knowledge of the geology of Antarctica -- even if based on the meager <2% of rock exposure for this continent-- has immeasurably increased over that quarter-century. Individual chapters cover the regional geology of the seven main physiographic regions of Antarctica: -the Antarctic Peninsula, -West Antarctica (Marie Byrd Land and Enderby Land), -Transantarctic Mountains, -the Shackleton Range and its surroundings (including the Bertrab, Littlewood and Moltke Nunataks), -Dronning Maud Land, -Lambert Glacier and the area surrounding it, -East Antarctica from Kaiser-Wilhelm-II.-Land to George V Land/Terre Adélie. Each chapter contains a topographic, historical and geological overview, a description of the respective geological units, their stratigraphy and related data and the tectonic structure of the respective region. The seven chapters were written by acknowledged specialists in their field who place the regional geology into a continent-wide/plate tectonic/geological context. 

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2. Modeling Ocean Heat Transport to the Grounding Lines of Pine Island, Thwaites, Smith, and Kohler Glaciers, West Antarctica

   https://doi.org/10.1029/2024GL110078  

   Dinh, Andy; Rignot, Eric; Mazloff, Matthew; Fenty, Ian (October 2024, Geophysical Research Letters)

   Abstract Pine Island, Thwaites, Smith, and Kohler glaciers in the Amundsen Sea Embayment (ASE) sector of West Antarctica experience rapid mass loss and grounding line retreat due to enhanced ocean thermal forcing from Circumpolar Deep Water (CDW) reaching the grounding lines. We use simulated Lagrangian particles advected with a looping 1 year output from the Southern Ocean high‐resolution model to backtrack the transport and cooling of CDW to these glaciers. For the simulated year 2005–2006, we find that the median time needed to reach the grounding lines from the edge of the ASE is 3 years. In addition, the Antarctic Coastal Current contributes an equal number of particles as off‐shelf sources to the grounding lines of Pine Island and Thwaites. For CDW coming from off‐shelf, results from SOhi indicate that 25%–66% of the cooling occurs within ice shelf cavities. 

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3. Energetics of surface melt in West Antarctica

   https://doi.org/10.5194/tc-15-3459-2021  

   Ghiz, M L; Scott, R C; Vogelmann, A M; Lenaerts, J T; Lazzara, M; Lubin, D (January 2021, The cryosphere)

   We use reanalysis data and satellite remote sensing of cloud properties to examine how meteorological conditions alter the surface energy balance to cause surface melt that is detectable in satellite passive microwave imagery over West Antarctica. This analysis can detect each of the three primary mechanisms for inducing surface melt at a specific location: thermal blanketing involving sensible heat flux and/or longwave heating by optically thick cloud cover, all-wave radiative enhancement by optically thin cloud cover, and föhn winds. We examine case studies over Pine Island and Thwaites Glaciers, which are of interest for ice shelf and ice sheet stability, and over Siple Dome, which is more readily accessible for field work. During January 2015 over Siple Dome we identified a melt event whose origin is an all-wave radiative enhancement by optically thin clouds. During December 2011 over Pine Island and Thwaites Glaciers, we identified a melt event caused mainly by thermal blanketing from optically thick clouds. Over Siple Dome, those same 2011 synoptic conditions yielded a thermal blanketing-driven melt event that was initiated by an impulse of sensible heat flux then prolonged by cloud longwave heating. In contrast, a late-summer thermal blanketing period over Pine Island and Thwaites Glaciers during February 2013 showed surface melt initiated by cloud longwave heating then prolonged by enhanced sensible heat flux. At a location on the Ross Ice Shelf adjacent to the Transantarctic mountains we identified a December 2011 föhn wind case with additional support from automatic weather station data. One limitation thus far with this type of analysis involves uncertainties in the cloud optical properties. Nevertheless, with improvements this type of analysis can enable quantitative prediction of atmospheric stress on the vulnerable Antarctic ice shelves in a steadily warming climate. 

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4. Flexural Subsidence Around Ross Island, West Antarctica

   https://doi.org/10.1029/2021GC010181  

   Jha, Sumant; Harry, Dennis_L; Wenman, Christopher_P; Mayle, Micah (April 2022, Geochemistry, Geophysics, Geosystems)

   Abstract Ross Island is located in the southern Victoria Land Basin along the western margin of the West Antarctic Rift System. Episodic volcanism since ca. 4.6 Ma produced a discontinuous sedimentary moat around the island, coeval with regional extension. The moat is a composite of four smaller sub‐basins created during distinct episodes of volcanism. Subsidence within each sub‐basin is modeled as bending of a continuous elastic plate, first considering subsidence that occurred only during the time in which the associated volcano was active, and then considering cumulative subsidence since the onset of volcanism on Ross Island. Models based on strata deposited in each sub‐basin during the time interval in which the respective volcano was active yield flexural rigidities ranging from 6–36 × 10¹⁸N‐m, with the lowest values associated with the youngest volcanoes on the south and southwest sides of the island. Models based on the entire stratigraphic interval deposited since the onset of volcanism yield flexural rigidities up to 20 times greater than models that consider only strata deposited within each sub‐basin when the associated volcano was active. Models of the composite basin overestimate the strength of the lithosphere due to inclusion of strata deposited during periods in which regional extension rather than local flexure dominated subsidence. The models indicate that Ross Island is in near flexural isostatic equilibrium with moderately low‐density (3,260 kg m⁻³) upper mantle, although an additional buoyant load equivalent to a mantle temperature anomaly of up to 200°C is permissible. 

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5. Rapid glacier retreat rates observed in West Antarctica

   https://doi.org/10.1038/s41561-021-00877-z  

   Milillo, P.; Rignot, E.; Rizzoli, P.; Scheuchl, B.; Mouginot, J.; Bueso-Bello, J. L.; Prats-Iraola, P.; Dini, L. (January 2022, Nature Geoscience)