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Sinkholes In Alabama Essay

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Alabama is divided into four main physical regions. First, the Coastal Plain dominates the southern half of the state. It is the home of the Black Belt, which contains rich, chalky soil, and consists mostly of lowlands and low ridges. Second, the Piedmont Plateau is situated just to the north in east-central Alabama. This area is known for its rolling hills and valleys, as well as Alabama’s highest elevation point—the Cheaha Mountain. Third, ridges and valleys surround the Piedmont Plateau to the north and west. These landforms run northeast-southwest, and extend as far south as Birmingham. Finally, the Appalachian Plateau makes up most of the northeast. Part of the Highland Rim and the floodplain of the Tennessee River cut into Alabama’s extreme …show more content…

Soluble carbonate rocks under the surface and the collapse of old mines are common causes for sinkholes. Much of Alabama’s land is underlain by limestone, which is vulnerable to dissolution and leads to the formation of caves or sinkholes. The largest sinkhole recorded in the state developed near Calera in 1972 and was 325 feet long, 300 feet wide, and 120 feet deep. Northeast Alabama also suffers from earthquakes due to the state’s proximity to the Southern Appalachian Seismic Zone that runs along the Appalachian Mountains. The largest earthquake recorded occurred October 1916 at a 5.1 magnitude and spanned multiple states. The second largest earthquake in Alabama occurred October 24, 1997 at a 4.9 magnitude. In addition to sinkholes and earthquakes, the state suffers landslides due to rock strength. Most of the state is categorized as argillaceous rocks such as shales, clayey soil, and poorly compacted fills. A few areas are classified as weakly cemented rocks and soils such as sandy soils and poorly cemented sandstone. Though there are clusters of strongly cemented rocks, much of the state is included in the weaker categories. This means that they are more susceptible to landslides when earthquakes occur. (Geological Survey of

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