Geomorphology of the Sub-Antarctic Australian Territory of Heard Island-McDonald Island

Kiernan, K; McConnell, Anne

doi:10.1080/00049189993693

Cited by 22 publications

(16 citation statements)

References 27 publications

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“…Glaciers at Kerguelen in the Southern Indian Ocean (Frenot et al, 1993; and in southern Patagonia have shown to be shrinking and retreating at accelerated rates (Aniya et al, 1997;Aniya, 1999;Rignot et al, 2003;Rivera & Casassa, 2004). Likewise, rapid glacier recession over the last decades, reflecting temperature rise since the 1950s and 1960s has been found in several locations, including Heard Island (Allison & Keage, 1986;Kiernan & McConnell, 1999;Budd, 2000), and the South Shetland Islands (Braun et al, 2001;Simões et al, 2004).…”

Section: Figure 15 -Total Change In Glacier Length For 103 Marine-tementioning

confidence: 97%

Föhn winds on South Georgia and their impact on regional climate

Bannister

King

2015

Weather

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South Georgia is a small and mountainous island, located in the remote Southern Ocean. The island's subantarctic climate is controlled by its location and steep orography; with 19 peaks over 2000m and situated within a belt of strong westerly winds South Georgia acts as an effective barrier to the winds that impinge upon it.Since the 1920s, average summer temperatures have risen by ~1 o C on South Georgia.Coupled with this has been an increase in the rate of glacial retreat throughout the last century, with glaciers on the northeast leeside of the island retreating at a faster rate than those on the southwest side. These asymmetrical changes are thought to be linked with the strengthening of the westerlies. If the strength of the westerlies is sufficient, downslope winds can develop on the leeside of the island causing significant temperature increases as the descending air warms adiabatically; this is known as the föhn effect. Therefore, the aim of this thesis is to investigate whether the observed asymmetric pattern of regional warming and glacier retreat are caused by the föhn warming process.To explore the link between the föhn effect and its impact on the regional climate of

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Section: Figure 15 -Total Change In Glacier Length For 103 Marine-tementioning

confidence: 97%

Föhn winds on South Georgia and their impact on regional climate

Bannister

King

2015

Weather

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“…Hall, 1983a,b;Heilbronn and Walton, 1984a;Löffler et al, 1983;Löffler, 1984;Holness and Boelhouwers, 1998;Kiernan and McConnell, 1999;Holness, 2001a). However, as few process observations and almost no experimental data are available, much of the interpretation of the processes active in the region remains speculative.…”

Section: Introductionmentioning

confidence: 99%

Sediment movement rates and processes on cinder cones in the maritime Subantarctic (Marion Island)

Holness

2004

Earth Surf Processes Landf

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Sediment transport in the scoria areas of Marion Island is primarily the result of needle-ice-induced frost creep associated with diurnal soil frost cycles. Clasts move most rapidly in fine textured areas (532 mm a −1 ; SD 382), more slowly in stony areas (161 mm a −1 ; SD 179), and most slowly in blocky areas (26 mm a −1 ; SD 23). Movement rates increase with increasing frost susceptibility of sediments, slope angle and altitude. The heave of dowels indicates that frost heave is active in all the scoria areas examined. The depth of effective frost heave increases with increasing altitude, with frost heave being restricted to the upper 100 mm of the soil in low altitude areas (<200 m). The heave of 150 mm dowels at the higher altitude sites provides evidence for segregation ice formation at depths greater than those associated with needle ice and diurnal soil frost cycles. Vertical movement profiles show a concave downslope profile, with sediment movement rates being most rapid at the soil surface and decreasing rapidly with depth. This profile shape is typical of areas dominated by diurnal freeze-thaw cycles and needle ice. The capture of sediments moving downslope in troughs and the sampling of material lifted by needle ice, suggest that sediment transport by needle ice under present conditions is extremely effective. Observations suggest that although both fine material and clasts are transported downslope, some preferential transport of clasts occurs.Experiment results and observations of soil frost processes suggest that frost creep associated with needle ice activity is the dominant slope process in the scoria areas of Marion Island. Other slope processes such as slopewash and debris flows appear to play a relatively minor and localized role in sediment transport. It is suggested that needle ice activity is likely to be the dominant geomorphic agent in other areas of the Subantarctic with similar climatic characteristics to Marion Island.

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“…Small sand beaches can be found in other protected north-facing sites (Hall and Denton, 2000), but are rare on the mainland. More extensive sand beaches are present on the sub-Antarctic islands, where the subaerial and glacial environment delivers large volumes of sand and gravel to the coasts of South Georgia (Figure 16(c) and 16 (d)) (Gordon and Hansom, 1986), Heard Island (Kiernan and McConnell, 1999), and the nearby Îles Kerguelen (Hansom and Gordon, 1998). Unlike the Arctic coast, where glacial tills and moraine are found in association with extensive deposits of fluviatile sands and gravels, a very different situation occurs on the Antarctic continent.…”

Section: Antarctic Coastal Geomorphologymentioning

confidence: 99%

Polar Coasts

Forbes

2011

Treatise on Estuarine and Coastal Science

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Geomorphology of the Sub-Antarctic Australian Territory of Heard Island-McDonald Island

Cited by 22 publications

References 27 publications

Föhn winds on South Georgia and their impact on regional climate

Föhn winds on South Georgia and their impact on regional climate

Sediment movement rates and processes on cinder cones in the maritime Subantarctic (Marion Island)

Polar Coasts

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