More Like this

1. Platelet Ice Under Arctic Pack Ice in Winter

   https://doi.org/10.1029/2020GL088898  

   Katlein, Christian; Mohrholz, Volker; Sheikin, Igor; Itkin, Polona; Divine, Dmitry V.; Stroeve, Julienne; Jutila, Arttu; Krampe, Daniela; Shimanchuk, Egor; Raphael, Ian; et al (August 2020, Geophysical Research Letters)

   Abstract The formation of platelet ice is well known to occur under Antarctic sea ice, where subice platelet layers form from supercooled ice shelf water. In the Arctic, however, platelet ice formation has not been extensively observed, and its formation and morphology currently remain enigmatic. Here, we present the first comprehensive, long‐term in situ observations of a decimeter thick subice platelet layer under free‐drifting pack ice of the Central Arctic in winter. Observations carried out with a remotely operated underwater vehicle (ROV) during the midwinter leg of the MOSAiC drift expedition provide clear evidence of the growth of platelet ice layers from supercooled water present in the ocean mixed layer. This platelet formation takes place under all ice types present during the surveys. Oceanographic data from autonomous observing platforms lead us to the conclusion that platelet ice formation is a widespread but yet overlooked feature of Arctic winter sea ice growth. 

   more » « less
2. Ice fracturing

   https://doi.org/10.1063/PT.3.5270  

   Schulson, Erland M. (July 2023, Physics Today)

   The process comprises the nucleation, propagation, and interaction of cracks. Understanding their micromechanics in ice is likely to help scientists understand fracture in all kinds of materials. 

   more » « less
3. Arctic Ice

   Keener, Cy; Holzman, Justine; Rigor, Ignatius; Woods, John (October 2022, Issues in science and technology)

   Integrating field data, remote satellite imagery, scientific analysis, and multimedia visual representation to document Arctic ice that is disappearing due to climate change, this artwork is the outcome of a four-year collaboration involving art, design, and polar science between artist Cy Keener, landscape researcher Justine Holzman, climatologist Ignatius Rigor, and scientist John Woods. With this work, Keener and Holzman’s goal is to make scientific data tangible, visceral, and experiential. They ask how artistic and creative practices can contribute to scientific endeavors while making scientific research visible to the public. 

   more » « less
4. Basal debris of the NEEM ice core, Greenland: a window into sub-ice-sheet geology, basal ice processes and ice-sheet oscillations

   https://doi.org/10.1017/jog.2022.122  

   Blard, Pierre-Henri; Protin, Marie; Tison, Jean-Louis; Fripiat, François; Dahl-Jensen, Dorthe; Steffensen, Jørgen P.; Mahaney, William C.; Bierman, Paul R.; Christ, Andrew J.; Corbett, Lee B.; et al (August 2023, Journal of Glaciology)

   Abstract We present new data from the debris-rich basal ice layers of the NEEM ice core (NW Greenland). Using mineralogical observations, SEM imagery, geochemical data from silicates (meteoric¹⁰Be, εNd,⁸⁷Sr/⁸⁶Sr) and organic material (C/N, δ¹³C), we characterize the source material, succession of previous glaciations and deglaciations and the paleoecological conditions during ice-free episodes. Meteoric¹⁰Be data and grain features indicate that the ice sheet interacted with paleosols and eroded fresh bedrock, leading to mixing in these debris-rich ice layers. Our analysis also identifies four successive stages in NW Greenland: (1) initial preglacial conditions, (2) glacial advance 1, (3) glacial retreat and interglacial conditions and (4) glacial advance 2 (current ice-sheet development). C/N and δ¹³C data suggest that deglacial environments favored the development of tundra and taiga ecosystems. These two successive glacial fluctuations observed at NEEM are consistent with those identified from the Camp Century core basal sediments over the last 3 Ma. Further inland, GRIP and GISP2 summit sites have remained glaciated more continuously than the western margin, with less intense ice-substratum interactions than those observed at NEEM. 

   more » « less
5. Formation of sea ice ponds from ice-shelf runoff, adjacent to the McMurdo Ice Shelf, Antarctica

   https://doi.org/10.1017/aog.2020.9  

   Macdonald, Grant J.; Popović, Predrag; Mayer, David P. (September 2020, Annals of Glaciology)

   null (Ed.)

   Abstract Ponds that form on sea ice can cause it to thin or break-up, which can promote calving from an adjacent ice shelf. Studies of sea ice ponds have predominantly focused on Arctic ponds formed by in situ melting/ponding. Our study documents another mechanism for the formation of sea ice ponds. Using Landsat 8 and Sentinel-2 images from the 2015–16 to 2018–19 austral summers, we analyze the evolution of sea ice ponds that form adjacent to the McMurdo Ice Shelf, Antarctica. We find that each summer, meltwater flows from the ice shelf onto the sea ice and forms large (up to 9 km 2 ) ponds. These ponds decrease the sea ice's albedo, thinning it. We suggest the added mass of runoff causes the ice to flex, potentially promoting sea-ice instability by the ice-shelf front. As surface melting on ice shelves increases, we suggest that ice-shelf surface hydrology will have a greater effect on sea-ice stability. 

   more » « less