Glacial System
A glacial system refers to the interconnected components of a glacier and its surrounding environment, including ice, snow, water, rock, and sediment. It encompasses the processes of glacier formation, movement, erosion, and deposition, as well as the impact of glaciers on landscapes and ecosystems. Glacial systems play a crucial role in shaping Earth's surface and influencing global climate patterns.
3 Key excerpts on "Glacial System"
eBook - ePubGlacier
Nature and Culture
- Peter G. Knight(Author)
- 2019(Publication Date)
- Reaktion Books(Publisher)
...From 1846, an engraving by John Emslie showing glaciers and perpetual snow as part of what we would now call the global climate system. 5 Glaciers and the Big Global System Glaciers are part of a complex, interconnected global environmental system. Their existence depends on a particular set of climatic conditions and is controlled by atmospheric circulation, the hydrological cycle, the positions of the wandering continents, the heights of mountain ranges, the tilt of the Earth’s axis, the luminosity of the Sun and many other factors. Changes in any one of these will affect the occurrence, properties and behaviour of glaciers. And they are all changing, all the time. What makes glaciers advance and retreat? The most direct way in which glaciers reflect environmental change is their expansion and contraction at timescales ranging from days to millions of years. These fluctuations reflect the amount of ice being supplied to the glacier by processes of accumulation (such as snowfall) and the amount being lost by processes of ablation (such as melting). This ‘mass balance’ is largely related to climate. If more ice is supplied than is lost the glacier will grow, and vice versa. The edge of the glacier is the position where the supply of ice from up-glacier is finally extinguished by ablation as the ice moves forward. Even when there is no long-term change, many glacier margins oscillate backwards and forwards a little every year in response to seasonal changes in ablation close to the margin. During summer, melting outweighs the forward movement of the ice and the margin retreats. During winter, ablation is low and the forward movement of ice exceeds the rate of ablation, so the margin advances. Over longer periods, changes in ablation and accumulation can be reflected in more substantial episodes of advance or retreat...
eBook - ePubSmall-Format Aerial Photography
Principles, Techniques and Geoscience Applications
- James S. Aber, Irene Marzolff, Johannes Ries(Authors)
- 2010(Publication Date)
- Elsevier Science(Publisher)
...Chapter 12 Glacial Geomorphology 12.1. INTRODUCTION Modern glaciers and ice sheets cover approximately 10% of the world’s land area. Of this, most glacier ice is found in Antarctica and Greenland with all other areas accounting for only about 5% of the total. During the Ice Age (Pleistocene Epoch) of the last one million years, glaciers and ice sheets expanded dramatically and repeatedly over large portions of northern Eurasian and North American lowlands and in mountains and high plateaus around the world. At times, the volume of glacier ice during the Pleistocene was at least triple that of today (Hughes et al., 1981). Global sea level declined by at least 120 m, which allowed ice sheets to spread over broad continental shelves, particularly north of Eurasia (Svendsen et al., 1999; Polyak et al., 2000). Geomorphology is the study of the Earth’s surficial landforms both on land and on the seafloor. This study is both descriptive and quantitative; it deals with morphology, processes, and origins of landforms. Glacier ice is a powerful agent that created many distinctive landforms that are well preserved nowadays in regions of former ice expansion. Glaciers modify the landscape in three fundamental ways by erosion, deposition, or deformation (Fig. 12-1). A given site may be subjected to each or all of these processes during the advance and retreat of a glacier, and repeated glaciation may overprint newer landforms on older ones. In addition, glacial meltwater is also an effective geomorphic agent that may erode or deposit conspicuous landforms in connection with glaciation. The results are complex landform assemblages that represent multiple glaciations during the Pleistocene. Aerial photography has long been utilized to illustrate, describe, interpret, and map the diverse types of landforms created by glaciation (e.g. Gravenor et al., 1960)...
eBook - ePubApplied Climatology
Principles and Practice
- Allen Perry, Dr Russell Thompson, Russell Thompson(Authors)
- 2013(Publication Date)
- Routledge(Publisher)
...Likewise, water resources become critical under extreme climate conditions, especially when supply and demand lose their synchronization under drought episodes. Frozen water bodies (i.e. glaciers) are the true ‘progeny’ of climate which controls all their physical and thermal characteristics. For example, the conversion of snow to glacial ice and the mass balance of glaciers are critically related to climatic conditions (especially atmospheric heat transfers). The influence of climate on geomorphic processes and landforms is not so convincing since, at scales finer than the global or regional, generalizations about the role of climatic inputs in landform evolution have proved more difficult to sustain. The response of a landform to climate is known as landscape sensitivity and lowsensitivity landforms retain their characteristic forms mainly in response to local features and actual morphology, for example the supply of debris to rock glaciers. Over the past century, the above-ground climate has been accepted as one of the main environmental factors involved in soil formation. Soils and climate are indeed intimately interrelated and they bring together two of the most critical environmental parameters of life on the earth. The most important climatic elements are solar radiation, soil temperatures (which control chemical reactions and biological activity) and the soil moisture budget. However, it is evident from present-day soil classifications that there are important deviations in the relationship between soil patterns and climate data, since climate is only one of some five factors responsible for soil formation (Jenny, 1941). Also, soil zonations, based on present-day climate, do not necessarily reflect the conditions under which soils were originally formed, which could have been so different in the past...
