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Ice sheet mass loss from Antarctica is greatest in the Amundsen Sea sector, where ‘warm’ deep seawater melts and thins the bases of ice shelves hundreds of meters below the sea surface. We use nearly 1000 paired salinity and oxygen isotope analyses of seawater samples collected on seven expeditions from 1994 to 2020 to produce a time series of glacial meltwater inventory on the Southeast Amundsen Sea continental shelf. Water column salinity-ẟ18O yield freshwater endmember ẟ18O values from −30.2 ‰ to −28.4 ‰, demonstrating that regional freshwater content is dominated by deep glacial melt. The meltwater fractions display temporal variability in basal melting, with 800 m water column meltwater inventories from 7.7 m to 9.2 m. This result corroborates recent studies suggesting interannual variability in basal melt rates of West Antarctic ice shelves and is consistent with the Amundsen region’s influence on ocean salinity and density downstream in the Ross Sea.

AGU Fall Meeting, in San Francisco (EE.UU), 9-13 december 2019, n 2010, International Ocean Discovery Programme site U1357 retrieved a 180 m thick sedimentary sequence from the Adélie Land continental shelf, offshore of the East Antarctic Ice Sheet. The core targeted an expanded sediment drift (termed the Adélie Drift) that provides an ultra-high resolution record of Holocene climate variability adjacent to the Mertz Polynya system, one of the largest exporters of sea ice and Antarctic Bottom Water along the East Antarctic margin. Sedimentation at this site is dominated by pelagic biosiliceous sedimentation with accumulation rates averaging ~1.5-2 cm/year, but is heavily influenced by sediment advection by the westward flowing Antarctic Coastal Current. Previously obtained Holocene marine archives have orders of magnitude lower sedimentation rates, and commonly alternate between massive (bioturbated) and laminated diatom ooze, which obscures the ability to resolve high-frequency change at sub-decadal scales. However, U1357B is continuously laminated, and combined with high sedimentation rates, affords an unprecedented opportunity to assess sub-decadal resolution climate and biological responses at the Antarctic oceanic margin. Specifically, this record identifies El Niño Southern Ocean (ENSO) teleconnections that could account for sea-ice variability, nutrient delivery and high productivity bloom events in the coastal polynyas along Adélie Land throughout the Holocene. Here, we discuss sedimentary processes associated with formation of the Adélie Drift deposit, and how reconstructions of sediment advection through time can be used to identify shifts in current strength through the Holocene. These currents are driven by katabatic and zonal winds, and are a strong influence on biological productivity in the region. Climatic conditions over the last 11,400 years are reconstructed using a range of CT scan images, lipid biomarkers, diatom analysis, and physical/geochemical core properties. Shifting sensitivity of this system to ENSO forcing over centennial to millennial timescales coincide with rapid baseline shifts in climate and sea-ice state, indicating the existence of tipping points along the coastal margin of East Antarctica.

In Central America, seasonal and interannual shifts in the position of the Intertropical Convergence Zone (ITCZ) control the hydrologic budget. To better understand long-term changes in regional ITCZ-driven precipitation we re-examined a coral δ18O record from a Porites lobata coral head near Secas Island (Core ID: S1) (7°59′ N, 82°3′ W) in the Gulf of Chiriquí on the Pacific side of Panamá. Linsley et al., (1994) originally published the 277-year time series and first described the presence of a narrow-band decadal cycle (period near 9–12 years) in δ18O. The original study did not present potential drivers for the decadal cycle, although they ruled out the influence of the sun spot cycle. Our re-analysis of this record supports the original interpretation that coral δ18O is largely responding to variations in precipitation and associated river discharge, but with a new proposed mechanism to explain the decadal mode. There is no similar decadal cycle in gridded instrumental sea surface temperature from the area, suggesting that the decadal coral δ18O signal results from hydrologic changes that influence coastal δ18O seawater. The decadal component in S1 δ18O is also coherent with a decadal mode embedded in the Pacific Decadal Oscillation (PDO) Index that we suggest has tropical origins. We speculate that the coral's temporary δ18O deviation (1900–1930) in the decadal mode from the corresponding bands in rainfall and the PDO can be ascribed to a weak PDO in addition to local Panama gap wind variability and its effect on moisture transport from the Atlantic to the Pacific. Ultimately, the Secas Island coral δ18O series records ITCZ-driven precipitation dictated by both the Atlantic and Pacific basins.

Remote areas harbor some of the world's most undisturbed ecosystems. Major conservation gains can be made by effectively protecting nature in these remote zones. Conducting conservation work in remote settings presents both unique challenges and promising opportunities. We discuss how five commonly used approaches for conservation (buy and protect conservation; conservation motivated by the intrinsic values of nature; ecosystem service based conservation; ecotourism driven conservation; and conservation enabled by community planning) can be optimally applied to protect ecosystems in these special settings. In this discussion we draw examples from two model remote sites: Palmyra and Tabuaeran Atolls. Spatial analyses conducted using population density as a proxy for remoteness indicate that many existing recognized protected areas already include remote regions, but that the vast majority of the overall remote zones on the planet are not yet formally protected. Initiating discussions that directly consider both the roadblocks and opportunities for conservation in remote areas will help increase our odds of successfully protecting biodiversity in these unique and strategically important contexts. © 2013 Elsevier Ltd.