It seems that you're in Germany. We have a dedicated site for Germany. Mechanical properties and fluid transport in rocks are intimately linked as deformation of a solid rock matrix immediately affects the pore space and permeability. The coupling of fluid circulation and deformation processes in crustal rocks results in significant complexity of the mechanical and fluid transport behavior.
This often poses severe technical and economic problems for reservoir and geotechnical engineering projects involved in oil and gas production, CO 2 sequestration, mining and underground waste disposal. Part I of the topical volume mainly contains contributions investigating the nucleation and evolution of crack damage in rocks, new or modified techniques to measure rock fracture toughness and a discussion of upscaling techniques relating mechanical and fluid transport behavior in rocks at different spatial scales.
Scientists also provide a numerical estimate of the time required for the ultimate formation of a steady-shaped U-shaped valley —approximately , years. In a weak bedrock containing material more erodible than the surrounding rocks erosion pattern, on the contrary, the amount of over deepening is limited because ice velocities and erosion rates are reduced. Glaciers can also cause pieces of bedrock to crack off in the process of plucking.
In ice thrusting, the glacier freezes to its bed, then as it surges forward, it moves large sheets of frozen sediment at the base along with the glacier. This method produced some of the many thousands of lake basins that dot the edge of the Canadian Shield.
Differences in the height of mountain ranges are not only being the result tectonic forces, such as rock uplift, but also local climate variations. Ongoing research is showing that while glaciers tend to decrease mountain size, in some areas, glaciers can actually reduce the rate of erosion, acting as a glacial armor. Depending on glacier regime, even steep alpine lands can be preserved through time with the help of ice.
Scientists have proved this theory by sampling eight summits of northwestern Svalbard using Be10 and Al26, showing that northwestern Svalbard transformed from a glacier-erosion state under relatively mild glacial maxima temperature, to a glacier-armor state occupied by cold-based, protective ice during much colder glacial maxima temperatures as the Quaternary ice age progressed.
Mechanical properties and fluid transport in rocks are intimately linked as deformation of a solid rock matrix immediately affects the pore space and permeability. Rock Damage and Fluid Transport, Part II by Arno Zang, , available at Book Depository with free delivery worldwide.
These processes, combined with erosion and transport by the water network beneath the glacier, leave behind glacial landforms such as moraines , drumlins , ground moraine till , kames, kame deltas, moulins, and glacial erratics in their wake, typically at the terminus or during glacier retreat.
Interplay of glacial erosion and tectonic forcing governs the morphologic impact of glaciations on active orogens, by both influencing their height, and by altering the patterns of erosion during subsequent glacial periods via a link between rock uplift and valley cross-sectional shape. At extremely high flows, kolks , or vortices are formed by large volumes of rapidly rushing water. Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called Rock-cut basins.
Examples can be seen in the flood regions result from glacial Lake Missoula , which created the channeled scablands in the Columbia Basin region of eastern Washington. Wind erosion is a major geomorphological force, especially in arid and semi-arid regions. It is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage—especially after being increased far above natural rates by human activities such as deforestation , urbanization , and agriculture.
Wind erosion is of two primary varieties: deflation , where the wind picks up and carries away loose particles; and abrasion , where surfaces are worn down as they are struck by airborne particles carried by wind. Deflation is divided into three categories: 1 surface creep , where larger, heavier particles slide or roll along the ground; 2 saltation , where particles are lifted a short height into the air, and bounce and saltate across the surface of the soil; and 3 suspension , where very small and light particles are lifted into the air by the wind, and are often carried for long distances.
Wind erosion is much more severe in arid areas and during times of drought. For example, in the Great Plains , it is estimated that soil loss due to wind erosion can be as much as times greater in drought years than in wet years.
Mass movement is the downward and outward movement of rock and sediments on a sloped surface, mainly due to the force of gravity. Mass movement is an important part of the erosional process and is often the first stage in the breakdown and transport of weathered materials in mountainous areas.
Mass-movement processes are always occurring continuously on all slopes; some mass-movement processes act very slowly; others occur very suddenly, often with disastrous results. Any perceptible down-slope movement of rock or sediment is often referred to in general terms as a landslide. However, landslides can be classified in a much more detailed way that reflects the mechanisms responsible for the movement and the velocity at which the movement occurs. One of the visible topographical manifestations of a very slow form of such activity is a scree slope.
Slumping happens on steep hillsides, occurring along distinct fracture zones, often within materials like clay that, once released, may move quite rapidly downhill. They will often show a spoon-shaped isostatic depression , in which the material has begun to slide downhill. In some cases, the slump is caused by water beneath the slope weakening it. In many cases it is simply the result of poor engineering along highways where it is a regular occurrence. Surface creep is the slow movement of soil and rock debris by gravity which is usually not perceptible except through extended observation.
However, the term can also describe the rolling of dislodged soil particles 0. The amount and intensity of precipitation is the main climatic factor governing soil erosion by water. The relationship is particularly strong if heavy rainfall occurs at times when, or in locations where, the soil's surface is not well protected by vegetation. This might be during periods when agricultural activities leave the soil bare, or in semi-arid regions where vegetation is naturally sparse. Wind erosion requires strong winds, particularly during times of drought when vegetation is sparse and soil is dry and so is more erodible.
Other climatic factors such as average temperature and temperature range may also affect erosion, via their effects on vegetation and soil properties. In general, given similar vegetation and ecosystems, areas with more precipitation especially high-intensity rainfall , more wind, or more storms are expected to have more erosion. In some areas of the world e. The size and velocity of rain drops is also an important factor. Larger and higher-velocity rain drops have greater kinetic energy , and thus their impact will displace soil particles by larger distances than smaller, slower-moving rain drops.
In other regions of the world e. In such situations, rainfall amount rather than intensity is the main factor determining the severity of soil erosion by water. In Taiwan , where typhoon frequency increased significantly in the 21st century, a strong link has been drawn between the increase in storm frequency with an increase in sediment load in rivers and reservoirs, highlighting the impacts climate change can have on erosion.
Vegetation acts as an interface between the atmosphere and the soil.
It increases the permeability of the soil to rainwater, thus decreasing runoff. It shelters the soil from winds, which results in decreased wind erosion, as well as advantageous changes in microclimate.
Divisions are encouraged to work with FEMA to establish such guidance prior to an event. For time range between 0 - 0. Only those routes that are critical to restoring traffic service are eligible for grade raises. Repair of minor erosion damage due primarily or wholly to rainfall and resulting from surface saturation of slopes and embankments, rather than from floodwaters, is not eligible. These methods develop as rapid growth of technology. Writing of Dance download rock damage and fluid transport part ii pageoph topical volumes pt - An American Ballroom Companion: Dance Instruction Manuals, ca. ER participation may be prorated.
The roots of the plants bind the soil together, and interweave with other roots, forming a more solid mass that is less susceptible to both water  and wind erosion. The removal of vegetation increases the rate of surface erosion. The topography of the land determines the velocity at which surface runoff will flow, which in turn determines the erosivity of the runoff.
Longer, steeper slopes especially those without adequate vegetative cover are more susceptible to very high rates of erosion during heavy rains than shorter, less steep slopes. Steeper terrain is also more prone to mudslides, landslides, and other forms of gravitational erosion processes.
Tectonic processes control rates and distributions of erosion at the Earth's surface. If the tectonic action causes part of the Earth's surface e. Because erosion rates are almost always sensitive to the local slope see above , this will change the rates of erosion in the uplifted area.
Active tectonics also brings fresh, unweathered rock towards the surface, where it is exposed to the action of erosion. However, erosion can also affect tectonic processes. The removal by erosion of large amounts of rock from a particular region, and its deposition elsewhere, can result in a lightening of the load on the lower crust and mantle. Because tectonic processes are driven by gradients in the stress field developed in the crust, this unloading can in turn cause tectonic or isostatic uplift in the region.
mail.wegoup777.online/el-eslabn-perdido-en-la-teologa.php Such a place has been called a " tectonic aneurysm ". Human land development, in forms including agricultural and urban development, is considered a significant factor in erosion  and sediment transport. In Taiwan, increases in sediment load in the northern, central, and southern regions of the island can be tracked with the timeline of development for each region throughout the 20th century. Mountain ranges are known to take many millions of years to erode to the degree they effectively cease to exist. Scholars Pitman and Golovchenko estimate that it takes probably more than million years to erode a mountain mass similar to the Himalaya into an almost-flat peneplain if there are no major sea-level changes.
Examples of heavily eroded mountain ranges include the Timanides of Northern Russia. Erosion of this orogen has produced sediments that are now found in the East European Platform , including the Cambrian Sablya Formation near Lake Ladoga. Studies of these sediments indicate that it is likely that the erosion of the orogen began in the Cambrian and then intensified in the Ordovician. If the rate of erosion is higher than the rate of soil formation the soils are being destroyed by erosion. Inceptisols are common soils that form in areas of fast erosion.
While erosion of soils is a natural process, human activities have increased by times the rate at which erosion is occurring globally. Excessive or accelerated erosion causes both "on-site" and "off-site" problems. From Wikipedia, the free encyclopedia. For other uses, see Erosion disambiguation. Processes which remove soil and rock from one place on the Earth's crust, then transport it to another location where it is deposited.
Further information on water's erosive ability: Hydraulic action. Main article: Coastal erosion. See also: Beach evolution.
Play media. Main article: Aeolian processes. See also: Climatic geomorphology. See also: Vegetation and slope stability. Main article: Erosion and tectonics. See also: denudation and planation. This section needs expansion. You can help by adding to it. November Further information: soil erosion and pedogenesis. Back to the search result list.
Table of Contents. Hint Swipe to navigate through the chapters of this book Close hint. Elsworth and Yasuhara conduct circulation experiments on fractures in novaculite and limestone, intermittently imaged by X-ray computer tomography. Xiao et al.