Implementing a cartographic repository of the postglacial Antarctic paleo-shorelines

An improved understanding of the chronology of Antarctic ice sheet deglaciation since the Last Glacial Maximum-LGM represents a fundamental tool to better define the origin of past and future meltwater influx in the global oceans (Whitehouse et al., 2012).

Relict shorelines and other evidence of past Relative Sea Level (RSL) evolution were widely used to understand past ice sheet history and to improve predictions of climate-sea level relationship evolution (Khan et al., 2015). In the last decades, RSL data in the Antarctic region have been mostly produced using raised marine features such as beach and marine deposits, marine terraces and isolation basins. The chronology of these paleo sea-level stands has been established through geomorphological and stratigraphic techniques (John & Sugden, 1971; Fretwell at al., 2010) and supported by radiometric dating from samples found in beach deposits and marine/freshwater sediments (Simms et al., 2011; Watcham et al., 2011).

Here we present a new cartographic approach, currently carried out along the Antarctic Peninsula and South Shetland Islands, which has a twofold aim: (i) the creation of an open access dataset including information about paleo-shorelines by using a uniform collecting pattern, and (ii) the production of a coherent database which can be used for improved spatial analyses useful to define the Antarctic shoreline evolution as well as better constrain the chronology of the deglacial history. As demonstrated by other free data-repositories (https://www.bgs.ac.uk/geological-data/national-geological-repository/) and similar examples (https://warmcoasts.eu/world-atlas.html), the new cartographic instrument, built in web-GIS format, will represent a very important tool for Antarctic coast investigations and a tool for better focusing future researches.

 

Bibliographic references

Fretwell P.T., Hodgson D.A., Watcham E.P., Bentley M.J. & Roberts S.J. 2010. Holocene isostatic uplift of the South Shetland Islands, Antarctic Peninsula, modelled from raised beaches. Quat. Sci. Rev., 29, 1880-1893.

John B.S. & Sugden D.E. 1971. Raised marine features and phases of glaciation in the South Shetland Islands. Br. Antarct. Surv. Bull., 24, 45-111.

Khan N.S., Ashe E., Shaw T.A., Vacchi M., et al. 2015. Holocene relative sea-level changes from near-, intermediate-, and far-field locations. Curr. Clim. Change Rep., 1, 247-262.

Simms A.R., DeWitt R. & Kouremenos P. 2011. A new approach to reconstructing sea levels in Antarctica using optically stimulated luminescence of cobble surfaces. Quat. Geochronol., 6, 50-60.

Watcham E.P., Bentley M.J., Hodgson D.A., Roberts S.J. et al. 2011. A new Holocene relative sea level curve for the South Shetland Islands, Antarctica. Quat. Sci. Rev., 30, 3152-3170.

Whitehouse P.L., Bentley M.J. & Le Brocq A.M. 2012. A deglacial model for Antarctica: geological constraints and glaciological modelling as a basis for a new model of Antarctic glacial isostatic adjustment. Quat. Sci. Rev., 32, 1-24.