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COMPILATION OF GEOMORPHOLOGICAL MAP FOR RECONSTRUCTING THE DEGLACIATION OF ICE-FREE AREAS IN THE MARTEL INLET, KING GEORGE ISLAND, ANTARCTICA
oleh: Kátia Kellem Rosa, Rosemary Vieira, Claudio Wilson Mendes Júnior, Enoil de Souza Júnior, Jefferson Cardia Simões
| Format: | Article |
|---|---|
| Diterbitkan: | União da Geomorfologia Brasileira 2013-03-01 |
Deskripsi
<span style="font-family: Times New Roman; font-size: small;"> </span><p class="MsoNormal" style="margin: 0cm 0cm 10pt; text-align: justify; line-height: normal; vertical-align: top; mso-outline-level: 4;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US">We compiled a geomorphological map and a reconstruction map of glacier extension and ice-free areas </span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-fareast-font-family: Batang; mso-ansi-language: EN-US;" lang="EN-US">in the Martel Inlet, located in King George Island, South Shetlands, Antarctica</span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US">. Glacier extension data were derived of the digitized over a orthophotomosaic (2003), SPOT (February, 1988; March, 1995 and 2000), Quickbird (October, 2006) and Cosmo-Skymed (February, 2011) images. This mapping was supported by fieldworks carried out in the summers of 2007, 2010 and 2011, and by topographic surveys and geomorphic map in the proglacial area. Several types of glacial deposits were identified in the study area, such as frontal and lateral moraines, flutes, meltwater channels</span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-fareast-font-family: Batang; mso-ansi-language: EN-US;" lang="EN-US"> </span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US">and erosional features like rock moutonnés, striations and </span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-fareast-font-family: Batang; mso-ansi-language: EN-US;" lang="EN-US">U-shaped valleys</span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US">. These features allowed reconstructing the evolution of the deglaciation environment in the Martel Inlet ice-free areas, which has been affected by a regional climate warming trend<em style="mso-bidi-font-style: normal;">.</em> </span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-fareast-font-family: Batang; mso-ansi-language: EN-US;" lang="EN-US">The mapped data indicated the glaciers in study area</span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US"> lost about 0.71 km² of their ice masses (13.2% of the 50.3 km² total area), without any advances during 1979-2011. Since those years these glaciers receded by an average of 25.9 m a<sup>-1</sup>. </span><span style="font-family: "Times New Roman","serif"; font-size: 12pt; mso-fareast-font-family: Batang; mso-ansi-language: EN-US;" lang="EN-US">These ice-free areas were susceptible to rapid post-depositional changes. </span></p><span style="font-family: Times New Roman; font-size: small;"> </span>