Presentation on theme: "Ice & Glaciers By: Mario Solórzano Arnold Inga Juan Arresis Carder Brown."— Presentation transcript:
Ice & Glaciers By: Mario Solórzano Arnold Inga Juan Arresis Carder Brown
Geographic Location Approximate Worldwide Area Covered by Glaciers square kilometers) Antarctica 11,965,000 (without iceshelves and ice rises) Total glacier coverage is nearly 15,000,000 square kilometers, or a little less than the total area of the South American continent. The numbers listed do not include smaller glaciated polar islands or other small glaciated areas, which is why they do not add up to 15,000,000.) Greenland1,784,000 Canada200,000 Central Asia109,000 Russia82,000 United States75,000 (including Alaska) China and Tibet33,000 South America25,000 Iceland11,260 Scandinavia2,909 Alps2,900 New Zealand1,159 Mexico11 Indonesia7.5 Africa10
Zones The accumulation zone is the area above the firm line, where snowfall accumulates and exceeds the losses from ablation, (melting, evaporation, and sublimation).
Light As well as warmer air directly melting the surface of the ice sheet, glaciers are an important part of the picture. Glaciers move ice from the ice sheet to the sea, and react quickly to changes in atmospheric conditions.
Temperatures Figure 9.40 Climatogram for McMurdo, Antarctica Latitude/Longitude = 77 o S; 166 o E Average Annual Temperature ( o C) = -17.0 Annual Temperature Range ( o C) = 23 Total Annual Precipitation (mm) = 7.8 Summer Precipitation (mm) = 3.7 Winter Precipitation (mm) = 4.1
Geological Factors Geological evidence for ice ages comes in various forms, including rock scouring and scratching, glacial moraines, drumlins, valley cutting, and the deposition of till and glacial erratic. Successive glaciations tend to distort and erase the geological evidence, making it difficult to interpret. The advent of sediment and ice cores revealed the true situation: glacials are long, interglacials short. It took some time for the current theory to be worked out.
Chemical Factors Sediment yields are high from glaciers, this suggests that water flux, rather than physical erosion, exerts the primary control on chemical erosion by glaciers. Potassium and calcium concentrations are high relative to other cations in glacial water, probably due to dissolution of soluble trace phases, such as carbonates, exposed by comminution, and cation leaching from biotite.
Species and Niche Polar bears are one of the many animals that depend on solid ice to survive. Thy need stable ice that will not break under them to live. But as global warming gets worse more and more ice melts so that means less ice for polar bears to live on.
Environmental Pressures In recent years it has been recognised that ice/sediment coupling occurred beneath the Quaternary ice sheets that advanced over the soft sediments of lowland areas. This paper looks in detail at the effects of this coupling on the sediments, which results in glaciotectonic deformation, and also discusses the interaction of deformation and deposition within the subglacial environment.
Human Impacts The effect of global warming has caused many glaciers to melt and that causes for more ocean water so ocean water level increases.