The formation of sinkholes has become a fairly common phenomenon in the state of Florida. Most sinkholes are small, but some sin
kholes have led to catastrophic property damage and loss of life. One September day in 1999, folks began to notice that Lake Jackson in the panhandle region was shrinking. Within a few days, it was almost gone. A sinkhole had opened beneath the lake and drained it, along with all of the fish and alligators. Another sinkhole formed just 10 miles from Walt Disney World® in August 2013, swallowing a 48-unit villa at Summer Bay Resort®. As aquifers lose water, their substrates can become weaker and less capable of supporting overlying strata and any human structures built upon them. In such cases, the land surface above may subside. Sometimes subsidence can occur locally and suddenly, in the form of sinkholes, areas where the ground gives way with little warning. Once the ground subsides, soil becomes compacted, losing the porosity that enabled it to hold water. Recharging a depleted aquifer may therefore become more difficult. Sinkholes can occur when ________.
-too much weight above an aquifer causes it to cave in
-excessive water use lowers a water table and weakens the substrate
-nonconsumptive use lowers an aquifer
-the water in an artesian aquifer is under sufficient pressure -that it breaks through to the surface
-the water level in an aquifer rises, pushing through to the surface
Sinkholes can occur when<u> excessive water use lowers a water table and weakens the substrate.</u>
Explanation:
There are various causes for sinkholes, but all are related to water and how this can affect the soil. One of the causes of sinkholes is the excessive use of water. Excessive use lowers the volume of water in aquifers. As a consequence, the substrates that are above the aquifer change. They can not support large amounts of weight, leading to a sinkhole and soil with low permeability.
Under the Endangered Species Act (ESA), plant and animal species may be listed as either endangered or threatened. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range. “Threatened” means a species is likely to become endangered within the foreseeable future.
During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles (sides) of the cell.
The answer is bioaccumulation. Bioaccumulation is when toxins build up in a food chain. The animals at the top of the food chain are affected most severely because the concentration of toxin becomes most concentrated in the body tissues of the animals at the top of the food chain.
