Unit 7 Day 6 Groundwater VA SOL SOL 9 The student will investigate and understand how freshwater resources are influenced by geological processes and the activities of humans. Key concepts include b. development of topography c. identification of groundwater zones including the water table, , and zone of ; e. dependence on freshwater resources and the effects of human usage on water quality; The contained by landmasses is mostly of that fresh water is locked in ice caps and Objective 1. Interpret a simple groundwater diagram showing the zone of aeration, the zone of saturation, the water table, and an . 2. Describe underground water sources (such as aquifers and ). 3. Explain the development of karst topography to include key terminology: joint, cavern, , carbonation, stalactite, and stalagmite. 4. Locate the region of karst topography in Virginia as the Valley & Ridge Province where /dolomite is common. Most of the remaining fresh water is stored . Ground Water If you drill a hole deep enough an . you will find water. Even in the ! Groundwater is present everywhere, but is only a small fraction of the Earth’s water supply. Groundwater Movement and Storage As the Water Cycle runs much of the precipitation that falls on land becomes groundwater. From there it will begin a journey back to the ocean again. is the process by which precipitation enters the ground and The Hydrosphere is the water on and in Earth’s crust. in a material . of the hydrosphere in contained in the is the percentage of 25 Well-sorted sand has a porosity of about 30% is the ability of a material to are natural underground openings that connect to the surface and are formed when groundwater dissolves limestone through it and depends on how well connected the pores are Sandstone, limestone and well-fractured bedrock is very permeable are is the depth at which groundwater completely of a material is the of the zone of saturation are dripstone formations that form slowly on the top of caves as water drips slowly leaving a tiny deposit of CaCO3 that accumulates over time is a through which groundwater flows Aquiclude is an impermeable barrier to groundwater are mound-shaped dripstone deposits that form underneath the stalactites. Dripstone columns are formed when stalactites and stalagmites grow together Karst Topography Limestone regions that have , sinks, and sinking streams are said to have topography named after a limestone region in Croatia where these features are especially well-developed. About 10% of the Earths surface and 15% of the United States is this type is a depression in the ground caused by the collapse of a cave Sinkholes are common in Florida, and Texas flow Virginia has an extensive cave system that extends Groundwater Erosion Most groundwater contains that forms when carbon dioxide dissolves in water and combines in water molecules. The attacks certain rocks Carbonate rocks such as limestone that consist mostly of CaCO3 are susceptible to acid dissolution through the that can be visited and explored quite easily Ground Water Systems Ground Water Systems Groundwater moves slowly but continuously through on its journey back to the oceans. The average length of time that groundwater remains underground is . have water temperatures higher than the human body and are common in the western United States where the subsurface is still hot from recent Groundwater can return to the surface at places where the Earth’s surface are that erupt at regular intervals , located in Yellowstone National Park in Wyoming is a famous geyser http://www.nps.gov/yell/photosmultimedia/yellowston elive.htm Wells Many homes in Norfolk use well water for lawns, utility, and even drinking water Well is a hole dug or drilled into the ground to reach a emerge where an aquifer and Aquiclude come in contact at the surface and sandstone , sand and gravel are common aquifers of groundwater Simple wells are dug below the water table into the is a lowering of the water table around the head of a well is the difference between the original water table level and the level in the pumped well Clay and shale layers are Aquiclude Many of the lakes in such as Florida are flooded sinkholes that are fed by . 27 is when precipitation and runoff is added back to the zone of saturation In coastal areas such as Norfolk If recharge does not keep pace with drawdown the wells in an area will go Confined Aquifers Water table aquifers are unprotected and . Confined aquifers are sandwiched between aquicludes that form barriers that prevent pollutants from reaching the ground water contain water between two aquicludes the freshwater supplies and makes well water undrinkable It is also believed that a near the mouth of the Chesapeake Bay 35 million years ago contaminated the aquifer by in the seawater into the parent bedrock Industrial and harmful chemical wastes from The is caused by the recharge areas being at a higher elevation Water Quality Earth’s most precious . Because of its natural filtering and availability groundwater is the main source of this vital need. Many geologic processes such as erosion can have harmful effects on our freshwater supplies improperly constructed or maintained dumpsites (or ) can contaminate groundwater for many miles around the source in solution by the fine-grained sediments It is important to realize that protecting our water supply is of vital importance. It is our responsibility to be aware of how human is the sinking of land elevation when too much groundwater is removed activities affect our resources and act (and vote) accordingly!