What conditions contribute to saltwater intrusion? What will be an ideal response?
Seawater and freshwater occur as separate bodies in the subsurface because of density differences.
Freshwater floats on top of denser saltwater. This occurs even in open water bodies until currents or
waves mix the two. Underground, these water bodies are isolated from forces that would tend to mix
them and are layered or stratified as a result. The position of the boundary between these water masses
is a function of water pressure. In coastal areas, increased outflow of freshwater will push the
boundary seaward, and decreased outflow will bring about saltwater invasion. Decreased flow of the
Nile River, after completion of the Aswan High Dam, has deprived the Nile Delta of water, thereby
causing saltwater to invade the area. Saltwater invasion can also occur locally as the result of pumping
in coastal areas. Not only is the water table drawn down, but the boundary between the fresh and
saltwater bodies is also drawn upward.
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Indicate whether the statement is true or false.
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A. Rio Grande B. East African C. Sonoran D. Reelfoot
How does the process and rate seafloor spreading affect sea level?
What will be an ideal response?
77) Which of the following is most closely associated with fjords?
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