rivers Flashcards
meaning of erosion
the break down and removal of rock
meaning of weathering
the break down of rock in-situ
what are the 4 types of erosion
hydraulic action,abrasion,attrition and solution
meaning of hydraulic action
the sheer force of the moving water against the banks can cause air to be trapped in the cracks and crevices weakens the banks
meaning of abrasion
rocks scrape,scour and rub along the river bed and banks
meaning of attrition
rocky material smash together and become rounder and smaller
meaning of solution
when minerals or rocks are dissolved by weak acids in the water
meaning of traction
rocks and boulders rolled along the river bed
meaning of suspension
fine,light materials,sand and silt carried along in the flow of water
meaning of saltation
small pebbles and stones are bounced along the river bed
what is the process by which the water moves from the sea,to the air,and then to the land
the water cycle
process by which a waterfall is formed(put in order):
a.hard rock that is overhang collapses
b.soft rock is undercut by erosional processes such as hydraulic action and abrasion
c.waterfall retreats upstream,leaving behind steep sided gorge
d.overhang
e.soft rock erodes creating plunge pool
ebdac
process by which a v shaped valley is formed(put in order):
a.mass movement occurs as material falls.further erosion by abrasion
b.fast water causes rough particles to be transported by river and scraped along river bed
c.deepens river=v-shape
d.sides exposed by weathering
e.vertical erosion by abrasion
f.river =no energy=no lateral erosion
bedafc
