Groundwater (karst) Flashcards
Zone of saturation
Pores full of water when it infiltrates into the ground
Water table
On top of the zone of saturation
Groundwater
Water that is beneath the water table in the zone of saturation
Zone of aeration
An area above the water table that isn’t 100% saturated and can absorb more water (holds air and water)
Aquifer
A rock layer that can store a substantial amount of water
What is the importance of aquifers?
Farmers in dry areas drill a well into them to access clean water for crops, drinking, and irrigation
What’s the difference between an artesian well and an ordinary well?
Artesian wells are drilled into an aquifer that is sandwiched between impermeable layers, and water from this well may flow to the surface under its own pressure.
Ordinary wells, on the other hand, are aquifers that are overlain by permeable rock, and require pressure to pump out the water
Why is groundwater so important?
Areas with no mountain ranges (prairies and plains) must rely on groundwater for their water source due to the lack of rainfall. This groundwater is used for farming and irrigation
Describe California’s sinking situation
California is using up so much groundwater that part of it is falling by 0.3m per year. This raises the risks of flooding and intense rain affecting sewage and water systems, roads, bridges, and canals.
Will affect fresh fruit farms and how we get produce
How does groundwater create landforms?
Hot groundwater contains more dissolved minerals, so when it comes to the surface, it quickly cools and can no longer hold the minerals it is carrying in solution.
Limestone is a type of rock that 100% dissolves in water, which allows it to be carried away in solution.
What are karst landscapes?
Regions underlain with highly water soluble rock like limestone
Valleys have little surface water as streams disappear underground and flow through subsurface caves
Sinkhole
The “youth stage” of a karst landscape, where the surface has numerous depressions but the roofs of the expanding caves underground have not yet begun to collapse.
Note: 2 or more sinkholes is a doline
Name the interior features of limestone caves
Stalactite: water drips from the ceiling of a cave, leaving icicle-like deposits
Stalagmite: the dripping limestone water falls to the floor, leaving a growing mound of deposit
Pillars: when stalagmites and stalactites join together
Curtains: pillars grow together and look like a curtain
Flowstones: a blob of limestone water deposition (runs down walls or along the cave floor)
How is limestone eroded and transported?
Easily eroded by solution (acid rain) and abrasion (mechanical weathering)
The dissolved limestone may be redeposited and carried away by underground rivers
What is karst topography?
Landforms associated with weathering
