التفاصيل البيبلوغرافية
| العنوان: |
A study of dune change in Victoria Valley, Antarctica between 1959 and 2002 |
| المؤلفون: |
Bourke, Mary C., McGowan, Hamish A., Finnegan, David C. |
| المساهمون: |
Catto, N.R. |
| بيانات النشر: |
Elsevier |
| سنة النشر: |
2007 |
| المجموعة: |
The University of Queensland: UQ eSpace |
| مصطلحات موضوعية: |
269901 Physical Geography, E1, 770502 Land and water management |
| الوصف: |
Evidence of global climate change is expected to be first seen in polar regions, where subtle changes in climate may have large impacts on fragile geomorphic systems. Polar dunes are one such system for which there is little precise information available. For example, the extent to which polar aeolian deposits are stabilized by ice-bonded sands is unknown. As a first step towards a better understanding of the response of polar desert aeolian systems, we have mapped the sand dunes in Victoria Valley, Antarctica over the past four decades. The dune field is located at the confluence of the Packard and Victoria Valleys and has been the focus of field measurement programs for more than 40 years. Previous studies indicate that dune mobility has been limited to the crests shifting over ice-cemented sand layers within the dune in response to the Valley’s bi-direction wind regime. This is believed to impede net migration of the dune field. Short-term field studies have shown erratic movement of the dunes with the range between –14 and 62 m. However, no study has been made of longer term change in the morphological character of the dune field. In this study we use vertical air photographs and LIDAR data to map dune change over a 43 year period. We assess change in dune position and morphology over time. We find that the dunes have migrated (up to 75 m), and that dune form has changed, principally by lateral coalescing and limb extension. Movement of the dunes suggests that migration is possible despite the presence of ice and snow within the dune core. In addition, these changes support earlier observations that indicate a net (westerly) migration driven by topographically channeled thermally generated easterlies and gradient southeasterly winds. We infer this to indicate that the region has not undergone significant change in weather patterns in the last four decades. This is in agreement with the findings of Ayling and McGowan (2006) who investigated dust deposits on the adjacent Victoria Lower Glacier. Accordingly, it ... |
| نوع الوثيقة: |
conference object |
| اللغة: |
English |
| تدمد: |
1040-6182 |
| Relation: |
orcid:0000-0002-2844-2084 |
| الاتاحة: |
https://espace.library.uq.edu.au/view/UQ:136765 |
| رقم الانضمام: |
edsbas.C50B9C25 |
| قاعدة البيانات: |
BASE |