Appearance of De Geer moraines in southern and western Finland — Implications for reconstructing glacier retreat dynamics
Appearance of De Geer moraines in southern and western Finland — Implications for reconstructing glacier retreat dynamics
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芬兰南部和西部德吉尔冰碛的出现——对重建冰川退缩动态的影响
DOI：
10.1016/j.geomorph.2015.12.005
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发表时间：
2016
期刊：
影响因子：
3.9
通讯作者：
A. Ojala
中科院分区：
文献类型：
--
作者：
A. Ojala
对芬兰南部和西部的激光雷达数字高程模型 (DEM) 进行了研究，以绘制和区分德吉尔冰碛、稀疏且分散的末端冰碛以及较大的末端冰碛特征（即冰缘复合体）的特征。结果表明，芬兰德吉尔冰碛和分散的端碛脊的出现和分布比之前认为的更为广泛。这可能归因于使用高分辨率 DEM 可以轻松检测和绘制这些特征，这表明 LiDAR 应用在地质和地貌研究中的效率。芬兰冰碛脊的不同外观和分布支持了之前的解释，即没有一个模型可能适合所有地点的德吉尔冰碛的起源和所有类型的末端冰碛。德吉尔冰碛的出现和间距可能是由于冰消过程中冰缘退缩的普遍速度、冰缘形成的前冰期水深以及与气候和地形相关的当地冰川动态的综合作用造成的。变化的粘土基消冰速率与不同且规则间隔的德吉尔冰碛脊的间距之间的相关性表明，消冰速率可能参与了德吉尔冰脊的形成过程，但需要更彻底的比较来了解德吉尔间距在多大程度上代表冰缘衰减的年速率和区域消冰的速度。
LiDAR digital elevation models (DEMs) from southern and western Finland were investigated to map and discriminate features of De Geer moraines, sparser and more scattered end moraines, and larger end moraine features (i.e., ice-marginal complexes). The results indicate that the occurrence and distribution of De Geer moraines and scattered end moraine ridges in Finland are more widespread than previously suggested. This is probably attributed to the ease of detecting and mapping these features with high-resolution DEMs, indicating the efficiency of LiDAR applications in geological and geomorphological studies. The variable appearance and distribution of moraine ridges in Finland support previous interpretations that no single model is likely to be appropriate for the genesis of De Geer moraines at all localities and for all types of end moraines. De Geer moraine appearances and interdistances probably result from a combination of the general rapidity of ice-margin recession during deglaciation, the proglacial water depth in which they were formed, and local glacier dynamics related to climate and terrain topography. The correlation between the varved clay-based rate of deglaciation and interdistances of distinct and regularly spaced De Geer moraine ridges indicates that the rate of deglaciation is probably involved in the De Geer ridge-forming process, but more thorough comparisons are needed to understand the extent to which De Geer interdistances represent an annual rate of ice-margin decay and the rapidity of regional deglaciation.