Low-altitude periglacial activity in southeastern Australia during the late Pleistocene

2021 ◽  
pp. 1-22
Author(s):  
Timothy T. Barrows ◽  
Stephanie C. Mills ◽  
Kathryn Fitzsimmons ◽  
Robert Wasson ◽  
Robert Galloway
Keyword(s):  
Major Influence ◽  
Glacial Cycle ◽  
Cold Environments ◽  
Exposure Dating ◽  
Southeastern Australia ◽  
Snow Storage ◽  
Sediment Loads ◽  
Run Off ◽  
Dry Conditions ◽  
Valley Fills

Abstract Only a small area of the Australian mainland was glaciated during the Pleistocene, whereas periglacial deposits are far more common, indicating that cold environments were extensive and a major influence on landscape evolution. Here we identify representative low-elevation examples of scree slopes and frost action, together with fans and valley fills, indicating pronounced erosion cycles during the Pleistocene. To date the deposits, we explore approaches using radiocarbon, optically stimulated luminescence, and profile dating using the cosmogenic nuclide 10Be. The radiocarbon and optical ages show that screes, alluvial valley fill, and fans were deposited between 66–13 ka during the coldest part of the last glacial cycle, and within the previous glacial cycle. Exposure dating indicates further landscape erosion cycles back to the mid Pleistocene. Together, the deposits indicate the frost cracking limit was ~1300 m lower at 680 ± 10 m and mean winter temperature was 8.2 ± 0.5°C colder than present. Periglacial conditions probably affected much of southeastern Australia. The treeless and dry conditions resulted in widespread erosion and increased run off. Combined with increased snow storage within catchments, rivers were paradoxically larger, with high seasonal discharge and sediment loads.

Late Pleistocene Glaciation of the Kosciuszko Massif, Snowy Mountains, Australia

2001 ◽  
Vol 55 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Timothy T. Barrows ◽  
John O. Stone ◽  
L. Keith Fifield ◽  
Richard G. Cresswell
Keyword(s):  
Late Pleistocene ◽  
Pleistocene Glaciation ◽  
Glacial Cycle ◽  
Cosmogenic Isotope ◽  
Geomorphic Mapping ◽  
Exposure Dating ◽  
Southeastern Australia ◽  
Blue Lake ◽  
Glacier Advance

AbstractLate Pleistocene glaciation of the Australian mainland was restricted to a small area of the southeastern highlands. Geomorphic mapping of the area and exposure dating using thein situproduced cosmogenic isotope10Be provides evidence for at least two distinct glaciations. The Early Kosciuszko glaciation consisted of a single glacier advance before 59,300 ± 5400 years ago (Snowy River Advance). The Late Kosciuszko glaciation comprised three glacier advances 32,000 ± 2500 (Headley Tarn Advance), 19,100 ± 1600 (Blue Lake Advance), and 16,800 ± 1400 years ago (Mt. Twynam Advance). The Early Kosciuszko glaciation was the most extensive and the Late Kosciuszko advances were progressively less extensive. These periods of glaciation in the highlands correspond to episodes of periglacial activity and peaks in lake levels and river discharge at lower elevations in southeastern Australia. Glacier advances on the Kosciuszko Massif correlate with advances in Tasmania, South America, and New Zealand and are broadly representative of hemispheric climate changes during the last glacial cycle.

scholarly journals A Spectral Analysis of Snow in Mt. Rainier

2018 ◽  
Vol 10 (3) ◽  
pp. 20
Author(s):  
Shrinidhi Ambinakudige ◽  
Pushkar Inamdar ◽  
Aynaz Lotfata
Keyword(s):  
Remote Sensing ◽  
Snow Cover ◽  
Thermal Emission ◽  
Major Influence ◽  
Landsat 8 ◽  
Run Off ◽  
Snow Covered Area ◽  
Covered Area ◽  
Local Water ◽  
Normalized Difference Snow Index

Snow cover helps regulate the temperature of the Earth's surface. Snowmelt recharges groundwater, provides run-off for rivers and creeks, and acts as a major source of local water for many communities around the world. Since 2000, there has been a significant decrease in the snow-covered area in the Northern Hemisphere. Climate change is the major factor influencing the change in snow cover amount and distribution. We analyze spectral properties of the remote sensing sensors with respect to the study of snow and examine how data from some of the major remote sensing satellite sensors, such as (Advanced Spaceborne Thermal Emission and Reflection Radiometer) ASTER, Landsat-8, and Sentinel-2, can be used in studying snow. The study was conducted in Mt. Rainier. Although reflectance values recorded were lower due to the timing of the data collection and the aspect of the study site, data can still be used calculate normalized difference snow index (NDSI) to clearly demarcate the snow from other land cover classes. NDSI values in all three satellites ranged from 0.94 to 0.97 in the snow-covered area of the study site. Any pollutants in snow can have a major influence on spectral reflectance in the VIS spectrum because pollutants absorb more than snow.

scholarly journals Main Results of Mapping Glacio-Nival Systems in the World Atlas of Snow and Ice Resources

1986 ◽  
Vol 8 ◽  
pp. 111-116
Author(s):  
Vladimir M. Kotlyakov ◽  
Natalia N. Dreyer ◽  
Valentina I. Kravtsova
Keyword(s):  
Air Temperature ◽  
Indirect Methods ◽  
Snow Storage ◽  
Surface Ablation ◽  
Run Off ◽  
The World ◽  
Complementary Nature ◽  
Liquid Precipitation ◽  
Ice Resources ◽  
Snow And Ice

The compilation of the Atlas was based on the concept of glacio-nival systems (and the fields of these systems), developed in the U.S.S.R. It became possible to map glacionival systems by using all available data and by the development of indirect methods of obtaining regime parameters, characterising the glacio-nival zones. This, in turn, made it possible to show, on maps of different scales, properties relating to glacio-nival phenomena and processes, such as air temperature in a glacierized zone, the amount of solid and liquid precipitation, snow storage, the accumulation and surface ablation of glaciers and melt run-off. The compilation of these maps has demonstrated their conformity and complementary nature, the principles of which were worked out in the course of creating the Atlas. Based on the experience of compiling hundreds of various maps, the paper describes some peculiarities of depicting different elements of glacio-nival systems on maps of different scales and shows ways to overcome shortages of data in preparing the maps.

scholarly journals Holocene Lake and Shallow Water Sediments at Mograt Island, Sudan

2017 ◽  
Vol 34 (1) ◽  
pp. 9-21
Author(s):  
Annett Dittrich ◽  
Sayantani Neogi
Keyword(s):  
Shallow Water ◽  
Soil Micromorphology ◽  
Archaeological Remains ◽  
Alluvial Deposits ◽  
Sediment Loads ◽  
Run Off ◽  
Soil Block ◽  
History Of ◽  
Soil Components ◽  
Shallow Water Sediments

Abstract This paper presents the results of stratigraphic excavation and soil studies carried out at Mograt Island, the largest of the Nilotic islands in Sudan. Due to its restricted insular environments, Holocene alluvial deposits were observed to be interlocked with archaeological remains of different periods, allowing for a combined chronostratigraphic approach to study both cultural and climatic events. To better understand the environmental context through soil components and pedological features at a microscopic scale, soil block samples were accordingly collected and studied by the application of soil micromorphology. This approach provides insights into the history of Nile terrace aggradation through the suspension of Nile sediment loads under stillwater conditions as well as of the periodical establishment of shallow water pools at the islands′ plateaus by the surface run-off from local rains. Since these patterns vary significantly from the present situation, they offer a key to the scenario in which specific early agricultural and animal herding practices evolved.

scholarly journals Muddied Waters: Perceptions and Attitudes towards Mangroves and Their Removal in New Zealand

2019 ◽  
Vol 11 (9) ◽  
pp. 2631 ◽  
Author(s):  
Amrit Melissa Dencer-Brown ◽  
Andrea C. Alfaro ◽  
Simon Milne
Keyword(s):  
Ecosystem Services ◽  
Nutrient Retention ◽  
Avicennia Marina ◽  
Mangrove Ecosystem ◽  
Structured Interviews ◽  
Ecological Value ◽  
Social Ecological ◽  
Sediment Loads ◽  
Run Off ◽  
Perceptions And Attitudes

Seaward expansion of New Zealand’s mangrove Avicennia marina (subsp.) australasica in estuaries has led to disparity in opinion over their social-ecological value. This study investigated existing stakeholders and interested parties’ perceptions and attitudes towards mangroves, focusing on four sites in Auckland. A mixed methods design was used consisting of semi-structured interviews, ratings of importance of mangrove ecosystem services and issues and Q-sorts on mangrove social-ecological statements. 29 participants were interviewed in person. Results revealed a disparity in perceptions and attitudes towards mangroves. Community Groups displayed strongly negative opinions towards mangrove preservation and Conservation Organisations expressed a strongly positive stance. The occupation of participants was a significant factor in the ratings. Overall, sediment and nutrient retention were rated as the most important ecosystem services. The desire for reversion of estuaries to a “pre-mangrove” state is the greatest issue affecting mangroves. Q-analysis revealed loading of participants onto two factors representing (1) a pro-preservation attitude towards mangrove and (2) a neutral view. Managing sediment loads and nutrient run-off in the wider catchment were highlighted as ways to reduce mangrove expansion. Improving water quality and the health of the harbour was of utmost priority to kaitiaki (Māori guardians of the environment). This study provides critical insights into the management of mangroves as social-ecological systems.

Optimizing the performance of continuous centrifugals by online monitoring of the sugar colour

2017 ◽  
pp. 699-703
Author(s):  
Trent Holcomb ◽  
Tim Diringer ◽  
Bjarne, Christian Nielsen
Keyword(s):  
Online Monitoring ◽  
Major Influence ◽  
Colour Measurement ◽  
Water Addition ◽  
Sugar Factory ◽  
Centrifugal Load ◽  
Run Off ◽  
Sugar End

Transfer of colorants within the sugar end of a sugar factory has a major influence on sugar quality. Colour components are not only transported downstream from the Aproduct evaporating crystallizers towards the molasses, they are also transported upstream by returning the run-off from the batch centrifugals and by returning dissolved Bsugar and Csugar. If both B and Csugar crystals are dissolved and returned to the standard liquor, the colorants in these sugar crystals will contribute significantly to the quality of the standard liquor. In the Nampa sugar factory (Idaho/USA) and in several other factories, the work of the continuous centrifugals has been monitored and optimized by installing a Neltec online colour measurement (the ColourQ 1700 CC) to indicate the colour of the sugar crystals within the continuous centrifugals. The influence of various parameters such as centrifugal load, water addition and steam addition on the colour of the crystals flowing up the screen has been tested. This article gives a summary of the results achieved during these tests.

A Spectral Analysis of Snow in Mt. Rainier

2018 ◽  
Vol 10 (3) ◽  
pp. 18
Author(s):  
Shrinidhi Ambinakudige ◽  
Pushkar Inamdar ◽  
Aynaz Lotfata
Keyword(s):  
Remote Sensing ◽  
Snow Cover ◽  
Thermal Emission ◽  
Major Influence ◽  
Landsat 8 ◽  
Run Off ◽  
Snow Covered Area ◽  
Covered Area ◽  
Local Water ◽  
Normalized Difference Snow Index

Snow cover helps regulate the temperature of the Earth's surface. Snowmelt recharges groundwater, provides run-off for rivers and creeks, and acts as a major source of local water for many communities around the world. Since 2000, there has been a significant decrease in the snow-covered area in the Northern Hemisphere. Climate change is the major factor influencing the change in snow cover amount and distribution. We analyze spectral properties of the remote sensing sensors with respect to the study of snow and examine how data from some of the major remote sensing satellite sensors, such as (Advanced Spaceborne Thermal Emission and Reflection Radiometer) ASTER, Landsat-8, and Sentinel-2, can be used in studying snow. The study was conducted in Mt. Rainier. Although reflectance values recorded were lower due to the timing of the data collection and the aspect of the study site, data can still be used calculate normalized difference snow index (NDSI) to clearly demarcate the snow from other land cover classes. NDSI values in all three satellites ranged from 0.94 to 0.97 in the snow-covered area of the study site. Any pollutants in snow can have a major influence on spectral reflectance in the VIS spectrum because pollutants absorb more than snow.

scholarly journals Remote Sensing of Snow in High Mountain Basins in Norway

1985 ◽  
Vol 6 ◽  
pp. 250-251 ◽  
Author(s):  
T. Andersen ◽  
N. Haakensen
Keyword(s):  
High Mountain ◽  
Snow Melt ◽  
Mountain River ◽  
Snow Storage ◽  
Run Off ◽  
Snow Covered Area ◽  
Covered Area ◽  
Vital Interest ◽  
Snow Conditions ◽  
Southern Norway

Information on snow conditions in high mountain river basins is of vital interest for flood predictions and power production. Based on techniques derived for mapping of snow cover from digital NOAA-data, relations are established between snow covered area and remaining snow storage for three basins in southern Norway. Together with estimates of the precipitation and information on maximum accumulated snow, the relation can be useful in run-off predictions for the snow-melt period.

Cosmogenic exposure dating in arctic glacial landscapes: implications for the glacial history of northeastern Baffin Island, Arctic Canada

2005 ◽  
Vol 42 (1) ◽  
pp. 67-84 ◽  
Author(s):  
Jason P Briner ◽  
Gifford H Miller ◽  
P Thompson Davis ◽  
Robert C Finkel
Keyword(s):  
Ice Sheet ◽  
Ice Cover ◽  
Baffin Island ◽  
Glacial Cycle ◽  
Arctic Canada ◽  
Last Glacial ◽  
Exposure Dating ◽  
New Information ◽  
Exposure Ages ◽  
The Last Glacial

Cosmogenic exposure dating and detailed glacial-terrain mapping from the Clyde Foreland, Baffin Island, Arctic Canada, reveal new information about the extent and dynamics of the northeastern sector of the Laurentide Ice Sheet (LIS) during the last glacial maximum (LGM). The Clyde Foreland is composed of two distinct landscape zones: (1) glacially scoured terrain proximal to the major sources of Laurentide ice that flowed onto the foreland, and (2) ice distal unscoured sectors of the foreland. Both zones are draped with erratics and dissected by meltwater channels, indicating past ice cover. We interpret the two landscape classes in terms of ice sheet erosive ability linked with basal thermal regime: glacially scoured terrain was occupied by erosive warm-based ice, and unscoured terrain was last occupied by non-erosive cold-based ice. Cosmogenic exposure ages from >100 erratics from the two landscape types have different age distributions. Cosmogenic exposure ages from the glacially scoured areas suggest ice cover during the LGM, followed by deglaciation between ~15 and ~12 ka. In the unscoured lowlands, the cosmogenic exposure ages have multiple modes ranging between ~12 and ~50 ka, suggesting multiple periods of cold-based ice cover during the last glacial cycle. In landscapes covered by cold-based ice, large numbers of cosmogenic exposure ages are required for elucidating glacial histories.

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