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Close-range sensors are employed to observe glaciological processes that operate over short timescales (e.g. iceberg calving, glacial lake outburst floods, diurnal surface melting). However, under poor weather conditions optical instruments fail while the operation of radar systems below 17 GHz do not have sufficient angular resolution to map glacier surfaces in detail. This letter reviews the potential of millimetre-wave radar at 94 GHz to obtain high-resolution 3-D measurements of glaciers under most weather conditions. We discuss the theory of 94 GHz radar for glaciology studies, demonstrate its potential to map a glacier calving front and summarise future research priorities.

This study finds that glaciers have existed in the Transantarctic Mountains for the past 60 million years, and that warm-based mountain glaciers were present in Antarctica long before ice sheets came to dominate the continent.

In this study, we compare equilibrium-line altitudes (ELAs) calculated using the area–altitude balance ratio (AABR) and the accumulation–area ratio (AAR) methods, with measured ELAs derived from direct field observations. We utilise a GIS toolbox to calculate the ELA for 64 extant glaciers by applying the AABR and AAR methods to DEMs and polygons of their geometry. The calculated ELAs (c-ELAs) are then compared to measured zero-net balance ELAs (znb-ELAs) obtained from mass-balance time series held by the WGMS for the same glaciers. The correlation between znb-ELAs and AABR (1.56)/AAR (0.58) c-ELAs is very strong, with an r2 = 0.99. The smallest median difference between znb-ELAs and c-ELAs (i.e. 65.5 m) is obtained when a globally representative AABR of 1.56 is used. When applied to palaeoglacier-climate applications, this difference translates to ~0.42°C, well within the uncertainty of palaeotemperature proxies used to determine mean summer temperature at the ELA. The more widely used mean AABR of 1.75 is shown to be statistically invalid due to the skewness of the dataset. On this basis, when calculating glacier ELAs, we recommend the use of a global AABR value of 1.56.

The Greenland Ice Sheet (GrIS) is known to have experienced widespread retreat over the last century. Information on outlet glacier dynamics, prior to this, are limited due to both a lack of observations and a paucity of mapped or mappable deglacial evidence which restricts our understanding of centennial to millennial timescale dynamics of the GrIS. Here we present glacial geomorphological mapping, for upper Godthåbsfjord, covering 5800 km2 at a scale of 1:92,000, using a combination of ASTER GDEM V2, a medium-resolution DEM (error

Ice streams are fundamental to ice sheet dynamics, but the mechanisms controlling their flow remain elusive. Here, the authors perform macro- and microscale analyses of mega-scale glacial lineations, which indicate a continuously accreting, shallow-deforming bed during ice stream flow.

All marine communities in Greenland are experiencing rapid environmental change, and to understand the effects on those structured by seaweeds, baseline records are vital. The kelp and coralline algae habitats along Greenland’s coastlines are rarely studied, and we fill this knowledge gap for the area around Nuuk, west Greenland. Using subtidal swath surveys, photo-quadrats, and grab samples, we characterised the diversity of floral and faunal assemblages in kelp forests and coralline algae beds. The most abundant herbivore assemblages and the most diverse communities occur in the interstitial habitats of rhodolith beds. In kelp forests, species diversity is higher in epi-benthic (photo-quadrat) and mid-water (swath) surveys. These habitats are not mutually exclusive; Agarum clathratum is prominent in coralline algal habitats, while crustose coralline algae cover the bedrock under kelp holdfasts. Overall, the suite of surveys used capture the diverse communities within kelp forests and coralline algae in Greenland and their differing role in the life history of the inhabitants. Furthermore, coralline algae beds are an important carbonate store, with CaCO3 concentrations ranging from 28.06 to 103.73 g·m−3. Our research sets the baseline for continued investigations and monitoring of these important habitats and their supported fisheries.