Bell Ringer Describe one way estuaries are degraded: Sedimentation (excess sediment due to erosion and deposition) Overfishing (destroys ecosystems/food chains) Damming for flood control (changes water quality and ecosystems) Bioaccumulation (buildup of toxins in organisms) Eutrophication (chemicals creating dead zones)

Today 5.5 Notes Permeability Lab

Groundwater

Groundwater Groundwater – water under the Earth’s surface in rock or soil Protected from weather changes, so stays the same temperature year-round

Groundwater Aquifer – permeable layer of rock or soil that holds and collects groundwater Two types of aquifers – confined and unconfined

Groundwater Unconfined aquifers – allow water to seep directly from the surface above them Confined aquifers – have a rock layer that prevents water from seeping from the surface above

Groundwater Recharge – natural refilling of an aquifer from precipitation and runoff On average, groundwater remains underground hundreds of years, so we need to ensure that the water is plentiful and safe

Dissolved Minerals Groundwater contains carbonic acid, created when carbon dioxide dissolves in water The acidic water dissolves certain rocks like limestone (________ weathering), forming caves chemical

Dissolved Minerals These dissolved minerals can turn back into rocks as the groundwater drips for a long time Linville Caverns

Dissolved Minerals Stalactites – calcite deposits that hang down from the ceiling of a cave (StalaCtites hang from the Ceiling) Stalagmites – calcite deposits that grow UP from the floor of a cave (StalaGmites grow up from the Ground) Transverse columns – when stalactites and stalagmites connect

Transverse Column Stalactites Stalagmites

Dissolved Minerals The dissolved minerals in groundwater can affect your house (NOT dangerous, just a nuisance) Hard Water – water that contains calcium, magnesium, or iron from dissolved minerals

Dissolved Minerals Effects of Hard Water: Soap leaves a residue after bathing, which can prevent soil and bacteria from effectively washing away Washed clothes or dishes can have mineral deposits left behind If mineral deposits are left in pipes, it can eventually clog them

Groundwater Flow Groundwater flows downhill due to gravity The steeper the slope, the ________ groundwater will flow Groundwater flow is usually very slow because the water has to squeeze through the tiny pores of the subsurface material The smaller the pores, the _______ the water will flow faster slower

Groundwater Flow Review: the higher a soil or rock’s porosity, the more water it can hold porosity = runoff

Groundwater Flow Permeability – the ability for water to pass through a material Depends on the size of the pores and how connected they are

Groundwater Summary: Porosity – holds the water Permeability – lets water through

Groundwater Flow Permeable rocks have large pores, so groundwater can flow up to 200m a year Examples: sandstone, limestone, and rubble (large, loose rocks) Impermeable (not permeable) rocks have very small pores, so groundwater can flow only about 0.5m a year Ex: shale and clay

Groundwater Flow Impermeable layers act as barriers to groundwater flow

The Water Table When water infiltrates the ground, it flows through the zone of aeration Zone of Aeration – area below the surface that can hold more water (aeration  air in the pores) There may be some water in the pores, but there is room for more Zone of aeration

The Water Table Zone of Saturation – area under the zone of aeration where every pore is filled with water Water Table – top of the zone of saturation, highest level where groundwater exists Zone of aeration

The Water Table Air and Water Water

The Water Table The depth of the water table varies, from close to the surface in swamps or deep below the surface in deserts

Wells and Springs Springs – where the water table meets the surface Water can trickle out of the ground, or it can create a whole stream Hot springs – springs with water warmer than 98.6oF (human body temp)

The Liard Hot Springs along the Alaska Highway Wells and Springs The Liard Hot Springs along the Alaska Highway What’s fueling the heat?

Wells and Springs Geysers – boiling hot springs that erupt at regular intervals, gushing hot water and steam Old Faithful – geyser in Yellowstone National Park that erupts almost every hour Geysers erupt with lots of force and pressure, while springs typically do not

Wells and Springs Wells – holes dug or drilled deep into the ground to reach an aquifer and then water is pumped up to the surface

Wells and Springs Artesian Wells – groundwater trapped in a confined aquifer that is naturally forced upward (no need for a pump)

Wells and Springs Summary: Springs – flow naturally to the surface Wells (other than artesian wells) – must be pumped to the surface

Permeability Lab Follow lab procedure CAREFULLY. Part one is just using the computers – YOUR CELL PHONE WILL NOT WORK Part two: Soil sample is at the back of the room. Only one member needs to come to get the soil sample. Follow clean-up precisely. Points will be deducted if you do not. I cannot emphasize enough – NO SOIL GOES DOWN THE DRAINS!!!!!! Put lab in basket when you are done