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Slump Structures
A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a slope. Movement is characterized by sliding along a concave-upward or planar surface. Causes of slumping include earthquake shocks, thorough wetting, freezing and thawing, undercutting, and loading of a slope. Translational slumps occur when a detached landmass moves along a planar surface. Common planar surfaces of failure include joints or bedding planes, especially where a permeable layer overrides an impermeable surface. Block slumps are a type of translational slump in which one or more related block units move downslope as a relatively coherent mass. A rotational slump occurs when a slump block, composed of sediment or rock, slides along a concave-upward slip surface with rotation about an axis parallel to the slope. Rotational movement causes the original surface of the block to become less steep, and the top of the slump is ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Wasting
Mass wasting, also known as mass movement, is a general term for the movement of rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is not entrained in a moving medium, such as water, wind, or ice. Types of mass wasting include creep, solifluction, rockfalls, debris flows, and landslides, each with its own characteristic features, and taking place over timescales from seconds to hundreds of years. Mass wasting occurs on both terrestrial and submarine slopes, and has been observed on Earth, Mars, Venus, Jupiter's moons Io, and on many other bodies in the Solar System. Subsidence is sometimes regarded as a form of mass wasting. A distinction is then made between mass wasting by subsidence, which involves little horizontal movement, and mass wasting by slope movement. Rapid mass wasting events, such as landslides, can be deadly and destructive. More gradual mass wasting, such as soil cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grade (slope)
The grade (also called slope, incline, gradient, mainfall, pitch or rise) of a physical feature, landform or constructed line refers to the tangent of the angle of that surface to the horizontal. It is a special case of the slope, where zero indicates horizontality. A larger number indicates higher or steeper degree of "tilt". Often slope is calculated as a ratio of "rise" to "run", or as a fraction ("rise over run") in which ''run'' is the horizontal distance (not the distance along the slope) and ''rise'' is the vertical distance. Slopes of existing physical features such as canyons and hillsides, stream and river banks and beds are often described as grades, but typically grades are used for human-made surfaces such as roads, landscape grading, roof pitches, railroads, aqueducts, and pedestrian or bicycle routes. The grade may refer to the longitudinal slope or the perpendicular cross slope. Nomenclature There are several ways to express slope: # as an ''angle'' of inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''escarpment''. Some sources differentiate the two terms, with ''escarpment'' referring to the margin between two landforms, and ''scarp'' referring to a cliff or a steep slope. In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side. More loosely, the term ''scarp'' also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation caused by coastal erosion at the base of the plateau. Formation and description Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by movement of the Earth's crust at a geologic fault. The first process is the more common type: the escarpment is a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio Department Of Natural Resources
The Ohio Department of Natural Resources (ODNR) is the Ohio state government agency charged with ensuring "a balance between wise use and protection of our natural resources for the benefit of all." ODNR regulates the oil and gas industry, the mining industry, hunting and fishing, and dams, while maintaining natural resources such as state parks, state nature preserves, state wildlife areas, state forests, and state waterways. It was created in 1949 by the Ohio Legislature. ODNR owns and manages more than 640,000 acres of land including 75 state parks, 23 state forests, 136 state nature preserves and 150 wildlife areas. The department has jurisdiction over more than 61,500 miles of inland rivers and streams, 451 miles of the Ohio River and 2.29 million acres of Lake Erie. ODNR is responsible for overseeing and permitting all mineral extraction, monitoring dam safety, managing water resources and mapping the state's major geologic structures and mineral resources. In addition, OD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthflow
An earthflow (earth flow) is a downslope viscous flow of fine-grained materials that have been saturated with water and moves under the pull of gravity. It is an intermediate type of mass wasting that is between downhill creep and mudflow. The types of materials that are susceptible to earthflows are clay, fine sand and silt, and fine-grained pyroclastic material.Easterbrook, D: “Surface Processes and Landforms”, page 78-79. Prentice-Hall, Inc, 1999 When the ground materials become saturated with enough water, they will start flowing (soil liquefaction). Its speed can range from being barely noticeable to rapid movement. The velocity of the flow is dictated by water content: the higher the water content is, the higher the velocity will be. Because of the dependency on water content for the velocity of the flow, it can take minutes or years for the materials to move down the slope. Features and behavior Earthflows are just one type of mass movement that can occur on a hill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swift Creek Landslide
The Swift Creek Landslide is an active, slow-moving landslide located in western Washington, USA, due east of Everson on Sumas Mountain. Asbestos laden sediment originating from the landslide has recently generated much interest in this area. Asbestos is a known carcinogen. EPA sampling has documented asbestos in sediments in Swift Creek and in downstream Sumas River. Average asbestos levels in Swift Creek dredged material exceed the level that, in construction materials, triggers worker safety requirements and material handling and disposal regulations. Cause Landslides in the Pacific Northwest have a number of causes. One is the geology of the area; layers of loosely consolidated sediments, such as sand, overlay strongly consolidated less permeable layers of sediments such as clays.Department of Ecology: Puget Sound Landslides. Retrieved March 1, 2008, from http://www.ecy.wa.gov/programs/sea/landslides/info/info.html That, in addition to a large amount of precipitation receiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumas Mountain
Sumas Mountain is a mountain located in Whatcom County, Washington, 15 miles northeast of Bellingham and southwest of Vedder Mountain. Located in the Skagit Range, the mountain is notable for its high biodiversity and year-round hiking trails. It is sometimes referred to as American Sumas to distinguish it from an identically named mountain across the Canada–United States border in British Columbia just to the north, both of which are drained by tributary creeks of the Sumas River. The mountain is largely owned by the Washington Department of Natural Resources, but some parcels are privately held. While the public land is open for recreation, it is managed primarily for timber harvest. Clearcuts are present on many slopes and most all the remaining forest is in varying stages of recovery and regrowth. Washington State Route 547, which traverses a low pass on the mountain's northern flank, runs northwest from the Mount Baker Highway, (SR 542) in Kendall to SR 9 in Sumas, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami
A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances) above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event. Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide. For this reason, it is often referred to as a tidal wave, although this usage is not favoured by the scientific community because it might give ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS ''Resolution''; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaii Island. Hawaii sits on the Pacific Plate and is the only U.S. state that is not geographically connected to North America. It is part of the Polynesia subregion of Oceania. The state of Hawaii occupies the archipelago almost in its entirety (includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
