...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth Surface Processes and Landforms: The journal of the British Geomorphological Research Group >Sub-annual moraine formation at an active temperate Icelandic glacier
【24h】

Sub-annual moraine formation at an active temperate Icelandic glacier

机译：在一个积极的温带冰岛冰川的年度冰碛形成

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper presents detailed geomorphological and sedimentological investigations of small recessional moraines at Fjallsjokull, an active temperate outlet of or AE fajokull, southeast Iceland. The moraines are characterized by striking sawtooth or hairpin planforms, which are locally superimposed, giving rise to a complex spatial pattern. We recognize two distinct populations of moraines, namely a group of relatively prominent moraine ridges (mean height similar to 1.2 m) and a group of comparatively low-relief moraines (mean height similar to 0.4 m). These two groups often occur in sets/systems, comprising one pronounced outer ridge and several inset smaller moraines. Using a representative subsample of the moraines, we establish that they form by either (i) submarginal deformation and squeezing of subglacial till or (ii) pushing of extruded tills. Locally, proglacial (glaciofluvial) sediments are also incorporated within the moraines during pushing. For the first time, to our knowledge, we demonstrate categorically that these moraines formed sub-annually using repeat uncrewed aerial vehicle (UAV) imagery. We present a conceptual model for sub-annual moraine formation at Fjallsjokull that proposes the sawtooth moraine sequence comprises (i) sets of small squeeze moraines formed during melt-driven squeeze events and (ii) larger push moraines formed during winter re-advances. We suggest the development of this process-form regime is linked to a combination of elevated temperatures, high surface meltwater fluxes to the bed and emerging basal topography (a depositional overdeepening). These factors result in highly saturated subglacial sediments and high porewater pressures, which induces submarginal deformation and ice-marginal squeezing during the melt season. Strong glacier recession during the summer, driven by elevated temperatures, allows several squeeze moraines to be emplaced. This process-form regime may be characteristic of active temperate glaciers receding into overdeepenings during phases of elevated temperatures, especially where their englacial drainage systems allow efficient transfer of surface meltwater to the glacier bed near the snout margin. (c) 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
机译：本文展示了Fjallsjokull的小胚胎冰片的详细地貌和沉积学研究，或者AE Fajokull，东南冰岛。冰莴苣的特点是醒目的锯齿或发夹平面形式，这些呈现局部叠加，产生复杂的空间模式。我们认识到两种不同的羊毛种群，即一组相对突出的羊毛脊（平均高度与1.2米类似）和一组相对低的缓解冰淇淋（平均高度与0.4米类似）。这两组经常发生在集/系统中，包括一个明显的外脊和几个较小的冰片。使用冰盖的代表性，我们通过（i）潜艇变形和抑制剥离直到或（ii）推动挤压汤来确定它们形成。局部，在推动期间也包含在冰片中的冰川裂口（Glaciofluvial）沉积物。我们首次到我们的知识，我们展示了这些冰片的这些冰片在每年使用重复未刷新的空中车辆（UAV）图像。我们为Fjallsjokull提供了一项概念模型，该概念模型在Fjallsjokull中提出了锯齿冰沙序列，包括（i）在冬季重新进展期间形成的熔化挤压事件和（ii）在冬季重新进展期间形成的小挤压冰片组。我们建议这种过程形式的制度的发展与升高的温度，高表面熔融通量的组合，高表面熔融通量与床和新兴的基础形貌（沉积过度膨胀）相关联。这些因素导致高度饱和的底纤维沉积物和高沉积物压力，这在熔体季节期间诱导电流变形和冰边缘挤压。夏季强劲的冰川衰退，由高温推动，允许几个挤压冰淇淋被施加。该过程形式的制度可以是在升高温度的阶段期间在升高的阶段后退到过度延长的活性温度冰川的特征，尤其是它们的盖子排水系统允许高效地将表面熔融转移到鼻子边缘附近的冰川床上。 （c）2020作者。 John Wiley＆Sons Ltd发布的地球表面流程和地貌

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号