Module 9 Flashcards
Groundwater
what sustainable development goal is focused on water
Goal 6, clean water and sanitation. “Ensure availability and sustainable management of water and sanitation for all”
where is most of the water excluding the ocean and ice
groundwater
groundwater
water beneath the surface (subsurface) of the earth. it fills cracks, cavities, and pore spaces
how does groundwater move
it moves through sediments and rocks. if goes from areas of recharge to areas of discharge
areas of recharge
hills, mountains, and areas of precipitation. topographic highs
areas of discharge
streams, lakes, oceans, etc.
aquifer
a rock or sediment that holds and transmits enough water to be useful as a source of water
aquitard
a rock or sediment with slow rates of water movement
examples of aquifers
sand, sandstone, gravel
examples of aquitards
shale, clay, till
porosity
volume of open space (pore space) within a body of rock or sediment. all space notoccupied my solid material
permeability
measure of how readily fluids pass through material
how do we learn about what lies below the ground surface
look for exposures, drilling cores (boreholes), geophysics, and ground penetrating radar
where are good exposures of subsurface
along creeks, lakeshore bluffs, and in quarries
drilling cores
taking samples of subsurface sediment/rock
artesian aquifers
confined
water table aquifer
unconfined aquifer
geophysical probes
placed in wells to measure physical properties of the materials
what can geophysical probes measure
gamma radiation, conductivity, and magnetic susceptibility
ground penetrating radar
GPR uses radiowaves to image the changes in properties of subsurface materials at relatively shallow locations (<25m)
what can GPR locate
buried pipes, unmarked graves, and also archaeological applications
what stratigraphy is left as a result of glaciers in southern ontario
alternating layers of fine-grained sediment, and coarse-sediments, which forms a “layer cake” of aquifers and aquitards
fine grained sediment (aquitards)
tills, lake muds
coarse-grained sediments (aquifers)
sands, gravel
why is permafrost important to canadians
40% of land area underlain by permafrost (50% in 70-90s). 25% Earths total land area
where is permafrost common
periglacial (cold climate) areas which undergo seasonal freezing and thawing
what does melting of permafrost cause
structural damage, infrastructure at risk, triggers landslides
