r)-creep- loose deposits that move = colluvium, very slow (cm/yr)-earthflow- narrow shape, bulging front (m/hr)-abrupt shock to porous, wet sediment leads to liquefaction-grainflow- sand grains, etc: angle of repose is exceeded (km/hr)-debris avalanche- rare, spectacular event (100km/hr)-huge masses, pulverize and continue moving (stratovolcanoes)* *40% water constitutes a streamMass Wasting in Cold Climates (especially active)* frost heaving- lifting of regolith by the freezing of ground-contained water* gelifluction- thin surface layer thaws in summer and refreezes in winter (unstable)-cm/yr* rock glaciers- ice cemented debris which move similar to glaciers-m/yr (Alps, Andes, Rockies)Subaqueous Mass Wasting-submarine slope failures cause turbidity currents* deltas- region of slumping, central channel to transport sediment, zone where sediment is deposited* continental slope- disturbed and contorted layering caused by earthquakes, slumping, and glacial cycles (ice ages) has built a thick wedge of sediment along base* oceanic island submarine flanks- lava flows and unstable rubble placed by massive volcanic landslidesTriggering of Mass Wasting Events* shocks- earthquakes* slope modification- human construction* undercutting- stream or surf action* exceptional precipitation- ground becomes saturated and unstable* volcanic eruptions- slope failure and large volumes of released water* submarine slope failures- high internal pressure of water trapped under sediment bed, methane gas of organic matter, angle of repose issuesMass Wasting Hazards* assessment of hazards-maps of geology surrounding the site* mitigation of hazards-drain/pump soil to de-saturate-empty dams-minimize activity in danger zones Chapter NineStreams: A body of water that flows down slope along a clearly defined natural passageway. Part of the hydrologic cycle.* streams as geologic agents: -carry water to the ocean-carry soluable salts to the ocean-shape the surface of the...
