SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA
A comparative study of changes at deglaciation environments was carried out at Wanda and Ecology glaciers, King George Island, Antarctica, by examining erosion and depositional processes. Data for the reconstruction of deglaciation were based on geomorphological and aerial photograph interpretations...
Published in: | Pesquisas em Geociências |
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Language: | Portuguese |
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Instituto de Geociências /Universidade Federal do Rio Grande do Sul
2009
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Online Access: | https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844 |
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ftunivfrgsojs:oai:seer.ufrgs.br:article/17844 2023-07-16T03:52:14+02:00 SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA Feições sedimentológicas e geomorfológicas do ambiente de deglaciação das geleiras Wanda e Ecology, ilha Rei George, Antártica ROSA, Kátia K. VIEIRA, Rosemary SIMÕES, Jefferson C. FERRANDO, Francisco J. 2009-12-31 application/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844 por por Instituto de Geociências /Universidade Federal do Rio Grande do Sul https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844 Pesquisas em Geociências; v. 36 n. 3 (2009): Pesquisas em Geociências; 315-326 1807-9806 1518-2398 Antártica Ilha Rei George sedimentação glacial sensoriamento remoto Geociências Antarctica King George Island glacial sedimentation remote sensing info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2009 ftunivfrgsojs 2023-06-25T21:31:40Z A comparative study of changes at deglaciation environments was carried out at Wanda and Ecology glaciers, King George Island, Antarctica, by examining erosion and depositional processes. Data for the reconstruction of deglaciation were based on geomorphological and aerial photograph interpretations, as well as on analysis of multi-yearspot satellite images. Subglacial processes were investigated by means of morphoscopic and granulometric analyses of sediments collected during the summer season, and co-variance between Ra (percentage of angular clasts) and C40 (percentage of clast radio c/a ≤ 0.4) indexes.These glaciers have been retreating rapidly since 1956, with no periods of expansion. However, it is possible to observe differences in both glaciers deglaciation processes. The Ecology glacier has lost 1.35 km2 , whereas the Wanda glacier only 0.64 km2 in five decades. The retreat of the Ecology glacier has been greater at the northern part of the proglacial zone; a low frontal moraine at the southern part indicates a recent glacier ice front stabilization. In the Wanda glacier, ice flow orientation has changed during different retreat phases, together withwith ice thickness decrease. The exposure of several landforms and proglacial deposits, such as flutes, kame terraces, morainic ridges, clast pavements, striated rocks and eskers all result from retraction. Abraded and subglacially transported sediments predominate at the deglaciation environment with meltwater. A large proportion of fine-grained sediments, striated rock surfaces, clast pavements, stoss and lee blocks, indicate that the two glaciers are wet based, having a temperate basal thermal regime. Um estudo comparativo da evolução dos ambientes de deglaciação foi realizado nas geleiras Wanda e Ecology, ilha Rei George, Antártica para a análise dos processos erosivos e deposicionais subglaciais destes ambientes. Os dados para a reconstrução da deglaciação resultam da interpretação geomorfológica e de fotogramas aéreos, juntamente com análise de ... Article in Journal/Newspaper Antarc* Antarctica Antártica King George Island Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) Ecology Glacier ENVELOPE(-58.476,-58.476,-62.177,-62.177) King George Island Wanda Glacier ENVELOPE(-58.358,-58.358,-62.108,-62.108) Pesquisas em Geociências 36 3 315 |
institution |
Open Polar |
collection |
Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) |
op_collection_id |
ftunivfrgsojs |
language |
Portuguese |
topic |
Antártica Ilha Rei George sedimentação glacial sensoriamento remoto Geociências Antarctica King George Island glacial sedimentation remote sensing |
spellingShingle |
Antártica Ilha Rei George sedimentação glacial sensoriamento remoto Geociências Antarctica King George Island glacial sedimentation remote sensing ROSA, Kátia K. VIEIRA, Rosemary SIMÕES, Jefferson C. FERRANDO, Francisco J. SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
topic_facet |
Antártica Ilha Rei George sedimentação glacial sensoriamento remoto Geociências Antarctica King George Island glacial sedimentation remote sensing |
description |
A comparative study of changes at deglaciation environments was carried out at Wanda and Ecology glaciers, King George Island, Antarctica, by examining erosion and depositional processes. Data for the reconstruction of deglaciation were based on geomorphological and aerial photograph interpretations, as well as on analysis of multi-yearspot satellite images. Subglacial processes were investigated by means of morphoscopic and granulometric analyses of sediments collected during the summer season, and co-variance between Ra (percentage of angular clasts) and C40 (percentage of clast radio c/a ≤ 0.4) indexes.These glaciers have been retreating rapidly since 1956, with no periods of expansion. However, it is possible to observe differences in both glaciers deglaciation processes. The Ecology glacier has lost 1.35 km2 , whereas the Wanda glacier only 0.64 km2 in five decades. The retreat of the Ecology glacier has been greater at the northern part of the proglacial zone; a low frontal moraine at the southern part indicates a recent glacier ice front stabilization. In the Wanda glacier, ice flow orientation has changed during different retreat phases, together withwith ice thickness decrease. The exposure of several landforms and proglacial deposits, such as flutes, kame terraces, morainic ridges, clast pavements, striated rocks and eskers all result from retraction. Abraded and subglacially transported sediments predominate at the deglaciation environment with meltwater. A large proportion of fine-grained sediments, striated rock surfaces, clast pavements, stoss and lee blocks, indicate that the two glaciers are wet based, having a temperate basal thermal regime. Um estudo comparativo da evolução dos ambientes de deglaciação foi realizado nas geleiras Wanda e Ecology, ilha Rei George, Antártica para a análise dos processos erosivos e deposicionais subglaciais destes ambientes. Os dados para a reconstrução da deglaciação resultam da interpretação geomorfológica e de fotogramas aéreos, juntamente com análise de ... |
format |
Article in Journal/Newspaper |
author |
ROSA, Kátia K. VIEIRA, Rosemary SIMÕES, Jefferson C. FERRANDO, Francisco J. |
author_facet |
ROSA, Kátia K. VIEIRA, Rosemary SIMÕES, Jefferson C. FERRANDO, Francisco J. |
author_sort |
ROSA, Kátia K. |
title |
SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
title_short |
SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
title_full |
SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
title_fullStr |
SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
title_full_unstemmed |
SEDIMENTOLOGICAL AND GEOMORFOLOGICAL FEATURES OF THE WANDA AND ECOLOGY GLACIERS DEGLACIATION ENVIRONMENT, KING GEORGE ISLAND, ANTARCTICA |
title_sort |
sedimentological and geomorfological features of the wanda and ecology glaciers deglaciation environment, king george island, antarctica |
publisher |
Instituto de Geociências /Universidade Federal do Rio Grande do Sul |
publishDate |
2009 |
url |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844 |
long_lat |
ENVELOPE(-58.476,-58.476,-62.177,-62.177) ENVELOPE(-58.358,-58.358,-62.108,-62.108) |
geographic |
Ecology Glacier King George Island Wanda Glacier |
geographic_facet |
Ecology Glacier King George Island Wanda Glacier |
genre |
Antarc* Antarctica Antártica King George Island |
genre_facet |
Antarc* Antarctica Antártica King George Island |
op_source |
Pesquisas em Geociências; v. 36 n. 3 (2009): Pesquisas em Geociências; 315-326 1807-9806 1518-2398 |
op_relation |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17844 |
container_title |
Pesquisas em Geociências |
container_volume |
36 |
container_issue |
3 |
container_start_page |
315 |
_version_ |
1771544959110873088 |