geol 106 unit 2


angle of repose


steepest angle at which material remains stableunconsolidated and granularlarger, angular particles maintain steeper slopes25-40 deg


chemical weathering


chemical trasnformatio (decompostition) into new conpound(s)


creep


gradual downhill movement of regolith


debris flow


rapid mass wastinglarge amounts of waterfollow channels/canyons


differential weathering


masses of rocks don't weather uniform uniformlycaused by mineral makeup, degree of jointing, climate


earthflow


saturated by rain/snowviscous and slowforms on hillsidesclay and silt


eluviation


washing out of fine soil components


erosion


physical removal of material by water, wind, ice


exfolitaion dome


slabs that separate due to continuous weathering


external processes


occur at/near Earth's surfacepowered by energy form sunweathering, mass wasting, erosionbreak rock and move debirs


fall


freefall of detached parts


flow


moves as viscous fluid


frost wedging


water gets into cracks > freezes and expands>inc pressure>enlarges fracturecommon in mntns with daily freeze/thawtemeperate climates


horizon


layers of soil


internal processes


powered by energy from earth's coremntn buliding, volcanic activity


lahar


debris flow of volcanic material


leaching


depletion of soluble materials from upper level


mass wasting


gravity causing rock/soil to move downward


parent material


source of weathered material that forms soildominant in young soilaffects weathering, soil formation, fertility


permafrost


permanently frozen ground


regolith


rock and mineral fragments that cover earth's surface produced by weathering


rockslide


sudden rapid movement when detached sediment/bedrock slides downoccurs in high mntns


secondary enrichment


concentrates mior amounts of metals into economically valuable concentrationsEITHER percolation removes undesired material leaving enriched upper zone OR percolation removes desired material and deposits it at lower zone


sheeting


igneous rock exposed by weathering and sheets of it break off


slide


material remains coherent and moves along defined surface


slump


slide on a curved surface


soil


life supporting materialmineral, organic material, water, air


soil profile


vertical cross section through all layers


soil taxonomy


classification system based on chemical.physical properties


soil texture


proportions of different particle sizesinfluence ability to reatin/transmit waterrarely one particle size; textural categories


solifluction


very very slow mass wastingsaturated with water (but water can't escape)


solum


true soilactive and living roots, plant and animal lifeO>B horizons


speroidal weathering


corners expose greater surface area and are weatheredforms round rockschemical weathering


talus slope


piles of loosed rocks at base of mntn


weathering


physical breakdown (disintigration) and cchemical breakdown (decomposition) of rocks mear earth's surface


alluvial fan


high gradient meets bread flat plain


alluvium


stream-deposited material


aquifer


permeable rock/sediments that transmits groundwater


aquitard


impermeable layers that hinder.prevent groundwater movement


arteisan well


water rises in well above level of original encounter


backswamp


marches where water can't flow up the levee and into the river


bar


channel deposits composed of sand and gravel


base level


lower limit to how deep a stream can erode


bed load


stream's load that is too heavy so it moves along the bottom


braided stream


complex network of converging and diverging channels


capacity


max load a stream can carry


cavern


underground chambers of eroded limestone


competence


max size particles a stream can carry


cone of depression


depression in water table resulting from drawdown


cut bank


zone of active erosion on outside of meander


cutoff


short channel segment cutting off and reconnecting meander


delta


deposits formed when stream enters calm water


dendritc pattern


irregularly branching tributary system


discharge


volume of water flowing past a certain point of a stream ina given unit of time


dissolved load


solution of dissolved materials in water


distributary


main channel divides into smaller ones


divide


imaginary line separating two drainage basins


drainage basin


land area that contirbutes water to a river system


drawdown


lowering of water table due to wells


evapotranspitation


amount of water evaporated and transpired by plants


flood


overflow of stream water when water exceeds capacity of channel


floodplain


flat valley floor covered with alluviumlateral erosion caused by shifting of meanders


geyser


intermittent hotsprings or fountainscolumns of water ejected with great force in various intervals


gradient


slop of stream channelvertical drop of stream ove specified distance


groundwater


water within zone of saturation


hot spring


water 6-9deg C warmer than mean annual air temp


hydrologic cycle


unending circulation of earth'c water supply


incised meander


meandering channel in steep narrow valley


infiltration


water that soaks into ground


karst topography


landscapes shaped by dissolving power of groundwatersinkholes


laminar flow


slow moving straight line paths


meander


streams with sweeping bends


natural levee


sediment bordering channels built by successive floods


oxbow lake


abandoned bend in meander


permeability


ability to transmit fluid


point bar


crescent shaped accumulation of sand/gravel deposited on the inside of a meander


porosity


volume of open spaces in rock/soil


radial pattern


stream diverges in spoke-like pattern


rectangular pattern


right angle bendsbedrock crisscrossed by joints


runoff


surplus water flowing over surface


saltation


jump/skip movement


settling velocity


speed at which particle falls through still fluidlarger particles settle fasterdenser particles settle faster


sinkhole


depressions in land


sorting


mechanism by which particles of various sizes are separatedparticles of the same size are deposited together


spring


natural flow of groundwater resulting when water table intersects ground surface


stream valley


channel and surrounding terain that contibutes to water in stream


suspended load


sediment suspended in water


transpiration


water relased by plants into atmosphere


trellis pattern


rectanuglar pattern where tributaties are parallel to each other


turbulent flow


water moving in eratic swirling motion


unsaturated zone


area above water table not saturated


water table


upper limit of groundwater


well


hole bored into zone of saturation


yazoo tributary


a tributary stream that flow parallel to stream because it can't breach the levee


zone of saturation


open space in rock and sediment filled with water


aftershock


adjustments following a large earthquakegenerate smaller earthquakes


asthenosphere


soft weak layer of upper mantleslightly viscous


body wave


waves that travel through earth's interiors-waves and p-waves


core


innermost part of earthiron-nickel rich3500 km thick


crust


thin rocky outer layer or earth


earthquake


vibration of earth produced by rapid release of energy


elastic rebound


vibration from earthquake


epicenter


location on surface directly above source of earthquake


fault


large fracture in earth's crust


fault creep


gradual fault displacement


focus


source or earthquake beneath surface


foreshock


small earthquakes preceding major earthquakedays or years


inner core


solid1200km radius


intensity


measure of the degree of earthquake shaking at a given locale based on damage


liquefaction


unconsolidated materials saturated with water move with earthquake


lithosphere


crust and upper mantlebrittle100km thick


lower mantle


very hotgradual flow2300 km thick


magnitude


amount of energy released at source or earthquake


mercalli intensity scale


Ca bulidings as its standard


moho


boundary between crust and mantle


moment magnitude


derived from amount of displacemnet that occurs at fault zonemore accurate measurement of magnitude


outer core


very hotliquid2300 km think


primary wave


push pull wavefastestcan trasnmit across earth (through solids)


richter scale


based on amplitude of waves recorded on seismogramestimates realtive size of earthquake


secondary wave


moves perpendicular to propogationcan't transmit through liquid


tsunami


seismic sea wave


seismology


study of earthquake waves


seismogram


records revealing seismic waves as elastic energy


surface wave


seismic waves that travel along crust


seismograph


intrument that records earthquake waves