| 1. |
- Bentley, Michael J., et al.
(author)
-
A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum
- 2014
-
In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 100, s. 1-9
-
Journal article (peer-reviewed)abstract
- A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms responsible for ice sheet retreat. Such understanding can be derived from a broad range of geological and glaciological datasets and recent decades have seen an upsurge in such data gathering around the continent and Sub-Antarctic islands. Here, we report a new synthesis of those datasets, based on an accompanying series of reviews of the geological data, organised by sector. We present a series of timeslice maps for 20 ka, 15 ka, 10 ka and 5 ka, including grounding line position and ice sheet thickness changes, along with a clear assessment of levels of confidence. The reconstruction shows that the Antarctic Ice sheet did not everywhere reach the continental shelf edge at its maximum, that initial retreat was asynchronous, and that the spatial pattern of deglaciation was highly variable, particularly on the inner shelf. The deglacial reconstruction is consistent with a moderate overall excess ice volume and with a relatively small Antarctic contribution to meltwater pulse la. We discuss key areas of uncertainty both around the continent and by time interval, and we highlight potential priorities for future work. The synthesis is intended to be a resource for the modelling and glacial geological community.
|
|
| 2. |
- Bravo, L, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
| 3. |
- Tabiri, S, et al.
(author)
-
- 2021
-
swepub:Mat__t
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Hodgson, Dominic A., et al.
(author)
-
Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands
- 2014
-
In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 100, s. 137-158
-
Journal article (peer-reviewed)abstract
- This paper is the maritime and sub Antarctic contribution to the Scientific Committee for Antarctic Research (SCAR) Past Antarctic Ice Sheet Dynamics (PAIS) community Antarctic Ice Sheet reconstruction. The overarching aim for all sectors of Antarctica was to reconstruct the Last Glacial Maximum (LGM) ice sheet extent and thickness, and map the subsequent deglaciation in a series of 5000 year time slices. However, our review of the literature found surprisingly few high quality chronological constraints on changing glacier extents on these timescales in the maritime and sub Antarctic sector. Therefore, in this paper we focus on an assessment of the terrestrial and offshore evidence for the LGM ice extent, establishing minimum ages for the onset of deglaciation, and separating evidence of deglaciation from LGM limits from those associated with later Holocene glacier fluctuations. Evidence included geomorphological descriptions of glacial landscapes, radiocarbon dated basal peat and lake sediment deposits, cosmogenic isotope ages of glacial features and molecular biological data. We propose a classification of the glacial history of the maritime and sub Antarctic islands based on this assembled evidence. These include: (Type I) islands which accumulated little or no LGM ice; (Type II) islands with a limited LGM ice extent but evidence of extensive earlier continental shelf glaciations; (Type III) seamounts and volcanoes unlikely to have accumulated significant LGM ice cover; (Type IV) islands on shallow shelves with both terrestrial and submarine evidence of LGM (and/or earlier) ice expansion; (Type V) Islands north of the Antarctic Polar Front with terrestrial evidence of LGM ice expansion; and (Type VI) islands with no data. Finally, we review the climatological and geomorphological settings that separate the glaciological history of the islands within this classification scheme. (C) 2014 The Authors. Published by Elsevier Ltd. All rights reserved.
|
|
| 8. |
- Nel, Werner, et al.
(author)
-
Earth science research on Marion Island (1996-2020) : a synthesis and new findings
- 2021
-
In: The South African Geographical Journal. - : Informa UK Limited. - 0373-6245 .- 2151-2418. ; 103:1, s. 22-42
-
Journal article (peer-reviewed)abstract
- Marion Island is a peak of a shield volcano located in the southern Indian Ocean. The island is strategically important for the collection of climatological data and marine and terrestrial research in a vast, oceanic region of the globe. This paper reviews the series of earth science programmes on Marion Island over the last 25 years, provides a synthesis of the research outcomes and demonstrates how field and laboratory methods have developed over time. Marion Island has, globally, one of the most active soil frost environments in a distinctive periglacial setting and understanding this contemporary periglacial environment has been a key objective of the research programmes. Geomorphological processes have important implications for local ecosystem functioning and define the regional and global significance for diurnal soil frost environments and climate change. Keeping abreast with the advancements of appropriate methodologies and technologies and the continued employment of a mix of new and established methods has driven the earth science research in this unique island environment. A series of short vignettes present the most recent advancements on old key questions and indicate that new techniques continuously challenge us to re-evaluate the most basic of assumptions that exist within our research.
|
|
| 9. |
- Nel, Werner, et al.
(author)
-
The effect of synoptic scale weather systems on sub-surface soil temperatures in a diurnal frost environment : preliminary observations from sub-antarctic Marion Island
- 2009
-
In: Geografiska Annaler. Series A, Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 91:4, s. 313-319
-
Journal article (peer-reviewed)abstract
- Marion Island in the South Indian Ocean has a maritime climate dominated by diurnal frost processes in the landscape. We test the hypothesis that synoptic time-scale measurements are essential in understanding the drivers of diurnal frost processes. Preliminary results from automated microclimate measurements in a polar desert habitat show that diurnal soil surface temperatures on Marion Island are influenced by a complex interaction of radiation balance, air mass circulation, cloud cover and snow. The passage of synoptic scale weather systems influences soil thermal characteristics through changes in dominance of the radiation budget. Soil frost on Marion appears to be dependent on clear skies, while synoptic weather systems affect the duration and intensity of soil frost processes and non-radiative heat fluxes. Air circulation patterns at Marion Island influence diurnal scale temperature fluctuations and its direct and indirect interactions with ecosystem processes. The data suggest that in a maritime sub-Antarctic environment the climatic drivers of soil frost occur at a finertemporal resolution than for seasonal and permafrost environments and needs to be measured at a diurnal time-scale to be meaningful.
|
|
| 10. |
|
|
