泥石流凍土ppt課件(編輯修改稿)
2025-05-28 06:04 本頁面
【文章內(nèi)容簡介】 ng, and returned vertically downward during a thaw. Thus, over time, material on a slope is likely to move downhill. Microlandslides and random movements such as overturned trees, etc., all contribute to creep. Part three 地球表層的塑造過程 環(huán)境地質(zhì)學(xué) Environmental Geology Mass Wasting Processes Landslides Landslide is the process whereby a distinct mass of rock or soil moves downslope due to gravity. Landslides, unlike creep, have one or more distinct failure surfaces. Landslide velocities are typically on the order of 1 m/day to perhaps 300 km/hr as in the special case of airentrapped landslides generated by earthquakes. Shreve (1968) believes that the prehistoric Blackhawk Landslide in California slid at immense speeds on a layer of pressed air that was trapped beneath the debris. The landslide, consisting of 320 million m3, traveled 8 km across a desert floor at an average slope of 176。 . [Hsu (1975) challenges the airlubrication空氣潤滑 hypothesis假說 in favor of a debris flow mobilized by collision of particles within a dustladen cloud.]. Part three 地球表層的塑造過程 環(huán)境地質(zhì)學(xué) Environmental Geology Mass Wasting Processes Landslides Landslide activity typically increases after prolonged rains, or after the frost leaves the ground in the spring. The novelist Firtsch (1980) describes the ominous hazard of landslides which weighs heavily on the minds of people who live in the steep slopes of the Swiss Alps: Part three 地球表層的塑造過程 環(huán)境地質(zhì)學(xué) Environmental Geology Mass Wasting Processes Landslides Classification of landslides. For simplicity, landslides can be classified into two groups: 1) translational, and 2) rotational. Part three 地球表層的塑造過程 環(huán)境地質(zhì)學(xué) Environmental Geology Mass Wasting Processes Landslides Translational landslides () slide along a bedding plane or other plane of weakness in the rock. The entire mass moves parallel to this plane, as illustrated in the rock slide in . Part three 地球表層的塑造過程 環(huán)境地質(zhì)學(xué) Environmental Geology Mass Wasting Processes Lands
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