Freshwater Flashcards
What is porosity?
How much space is in a rock for water or air to fill.
What are some factors that affect porosity and permeability?
- Texture/shape of grains
- Sorting
- Density
What is permeability?
How easily water can move in-between spaces.
What are some factors that affect porosity and permeability?
- Texture/shape of grains
- Sorting
- Density
What increases porosity?
- Rounded sediments
- Well sorted
- Loosely packed
What decreases porosity?
- Angular sediments
- Poorly sorted
- Tightly packed
What increases permeability?
- Large particles
- Connectedness
- Well sorted
What decreases permeability?
- Small particles
- Low connectedness
- Poorly sorted
True or false: it is possible to be porous and impermiable.
T R U E
What is an aquifer?
A unit of permeable and porous rock that contains water which we pump from
What makes a good aquifer?
- Balance of porosity and permeability
- Sandstone
- Gravel
- Fractured rocks
What makes a bad aquifer?
- Impermeable rock/sediments
- CLAY
What are the characteristics of confined aquifers?
- Saturated rock
- Impermeable layers
- Adds pressure and allows water to rise
What are the characteristics of unconfined aquifers?
- Open to the surface
- Rivers show the top upper limit
- MOST CONTAMINATED
Why are unconfined aquifers more contaminated?
- Rain brings pollution into the aquifer which causes it to be more contaminated
- Garbage, human waste, pollution
What is the zone of accumulation?
More SNOW than MELTING
What is the zone of ablation?
More MELTING than SNOW
What is the line of equilibrium?
The boundary between the zone of ablation and the zone of accumulation.
What is a glacial till?
Unsorted sediments weathered, eroded, and deposited by a moving glacier.
What is a moraine?
A pile of glacial till that is left behind at the end of the glacial advancements.
What is drumlin?
A tear-shaped pile of subglacial till shaped by the movement of an overlying ice sheet.
What is a meltwater stream?
A stream of meltwater originating from the front of the glacier.
