SINKHOLES Melanis Stepanian 111719 Professor Jennifer Bjerke What

SINKHOLES Melanis Stepanian 11/17/19 Professor Jennifer Bjerke

What is a Sinkhole? ■ A sinkhole occurs when the ground collapses ■ This is usually due to the fact that the rock below naturally dissolves in the groundwater. When it rains, the water is absorbed into the ground and starts to dissolve the rock formations underground. This creates open areas underground where the land above will be unable to support itself, causing the ground to fall. ■ Since Florida is underlaid with limestone, which dissolves very easily when it rains. ■ When the rainwater combines with the decaying vegetation, Limestone dissolves with the acidic measure

Limestone (and other minerals) in Florida ■ Limestone is a sedimentary rock that is mainly made up of calcium carbonate or dolomite ■ Florida used to be (shallowly) covered in sea water so the limestone was formed by the accretion of shells. ■ Limestone is classified as a marine deposit and has been collected and built-up for millions of years ■ Limestone can be dissolved naturally by using very mild acids. Specifically, mild acids are formed when rain water combines with carbon dioxide found in the air and soil.

Where sinkholes are likely to occur ■ Sinkholes can occur anywhere there is ground and water, says Walsh, “And where there’s one sinkhole, there are bound to be others. ” ■ According to the article “These Are Places You Are Most Likely To Be Swallowed By A Sinkhole”, the USGS discusses that the most damage due to sinkholes has occurred in the states of: Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. ■ The photo presents a map that reveals underground areas, called cavities, where sinkholes are likely to occur and create severe damage ■ The rock types shown on the map, evaporite and carbonate rock, are inclined to dissolve in water. https: //www. businessinsider. com/where-youll-be-swallowedby-a-sinkhole-2013 -3

Top 10 Sinkhole. Prone Counties in Florida ■ According to the insurance site The Insurance Journal, the top 10 counties in Florida that are likely to be effected by sinkholes are: – Pasco – Hernando – Hillsborough – Marion – Pinellas – Citrus – Polk – Orange – Seminole – Lake ■ They used a tool called Risk. Meter Online, which compares earthquake information, FEMA flood zones, distance to coast, and other real time reports in order to determine how likely an area is to experience a disaster based on the proximity to other natural hazards. https: //www. insurancejournal. com/news/southeast/2011/03/30/19 2278. htm.

Rock Types: Evaporites ■ Evaporite rocks are a type of sedimentary rock. https: //www. youtube. com/watch? v=SEFnk. XFq 8 j. I – They are formed when a body of water (like a lake or a sea) dries up. The evaporation of the water leaves behind deposits. The remaining deposits build up to create evaporite rock types. – According to the video, even though rock salt is solid, it can be morphed into different shapes with low pressures in a short period of time. – Specific evaporites include salt, gypsum, and anhydrite https: //www. slideshare. net/Himadri. Samal/ev aporites-79462444

Rock Types Continued: Carbonates ■ Carbonates are also a type of sedimentary rock. – – This type of rock forms when particles, which are made up of mainly carbonate materials, accumulate and create a cement. Carbonate materials include the shells of organisms and skeletal pieces. These remains come together at the bottom of a body of water, usually shallow and warm, in order to create carbonate rock. http: //www. calcium-carbonate. org. uk/calciumcarbonate/caco 3 -geology. asp ■ Two major kinds of carbonates are limestone and dolostone. https: //geology. com/rocks/limestone. shtml

Types of Sinkholes ■ There are three types of sinkholes: Dissolution, Cover-subsidence, and Cover-collapse ■ Dissolution, also known as solution, sinkholes occur when water dissolves the bedrock under the surface of the ground which ultimately creates a depression. On a carbonate surface, the depression sometimes speeds up the amount of water drained. This type of sinkhole is common in Florida. Watch this video to see how this type of sinkhole occurs: https: //www. youtube. com/watch? v=e 8 Fwbw. Uvw. Cc ■ Cover Subsidence sinkholes occur in areas where bedrock is covered by sand. When the bedrock erodes, the sand (which is composed of mainly clay) begins to fill the hole and rather than creating a sudden hole, the land surface begins to sink. Watch this video to see how this type of sinkhole occurs: https: //www. youtube. com/watch? v=_N 0 T_p 2 J 4 ps Dissolution Sinkholes Cover Subsidence Sinkholes https: //www. usgs. gov/special-topic/water-scienceschool/science/sinkholes? qtscience_center_objects=0#qt-science_center_objec

Types of Sinkholes Continued. . . ■ Cover collapse sinkholes cause very severe damage and is the most dangerous type of sinkhole. The rock below the surface is eroded away and the surface begins to lose stability, ultimately resulting in a sudden collapse, which can take weeks to years! Watch this video to see how this type of sinkhole occurs: https: //www. youtube. com/watch? v=Tbi. JOSkn 9 t. E https: //www. usgs. gov/special-topic/waterscience-school/science/sinkholes? qtscience_center_objects=0#qtscience_center_objects

Case Study: Sinkhole Swallows a Man’s Room While He’s Asleep ■ In March of 2013 at around 11 pm in Tampa, Florida, a 36 -year-old man’s bedroom had been swallowed by a sinkhole. ■ His brother heard him shout for help and as he walked into his room, he realized that his brother’s bedroom was gone. The man was presumed dead. The remaining residents of the home, 5 people, escaped before the sinkhole could cause greater damage. ■ The sinkhole was approximated to be 30 feet across the surface and about 30 feet deep. ■ The hole started with the bedroom and vegan expanding outward, taking more of the house into the sinkhole with it. The homes in the area were evacuated for their protection due to the expanding of the sinkhole.

Case Study: Two Homes Swallowed by a Sinkhole in Florida ■ In July of 2017, CNN reported that a sinkhole destroyed two homes in Land O’ Lakes (about 20 miles North of Tampa, FL) ■ The sinkhole was estimated to be 50 feet deep and had a diameter of 225 feet. ■ This sinkhole is considered to be the largest one in Pasco County in the past 30 years, according to CNN. The sinkhole can also be classified as a dissolution sinkhole. ■ Thankfully, there were no injuries reported and life will not return to normal for the residents for several weeks or months. https: //www. cnn. com/2017/07/14/us/sinkholeflorida/index. html

References: ■ “Limestone, Shell, Dolomite. ” Florida Department of Environmental Protection, https: //floridadep. gov/water/miningmitigation/content/limestone-shell-dolomite. ■ W. Schmidt, R. W. Hoenstine, M. S. Knapp, E. Lane, G. M. Ogden Jr. and T. M. Scott (1979). The Limestone, Dolomite and Coquina Resources of Florida. Report of Investigations No. 88. Bureau of Geology, Florida Department of Natural Resources. ■ “The Rock Cycle - Revision 2 - KS 3 Chemistry - BBC Bitesize. ” BBC News, BBC, https: //www. bbc. co. uk/bitesize/guides/zwd 2 mp 3/revision/2. ■ Welsh, Jennifer. “These Are The Places You Are Most Likely To Be Swallowed By A Sinkhole. ” Business Insider, 6 Mar. 2013, https: //www. businessinsider. com/where-youll-be-swallowed-by-a-sinkhole-2013 -3 ■ Rinkesh. “Causes, Effects and Types of Sinkholes. ” Conserve Energy Future, 25 Dec. 2016, https: //www. conserveenergy-future. com/causes-effects-and-types-of-sinkholes. php. ■ Houser, Newt, et al. “Florida's Top 10 Sinkhole-Prone Counties. ” Insurance Journal, 30 Mar. 2011, https: //www. insurancejournal. com/news/southeast/2011/03/30/192278. htm. ■ “Introduction. ” Carbonates Rocks, http: //www. geosci. usyd. edu. au/users/prey/Field. Trips/Yass 04/Carbonates. html. ■ Pearson, Michael. “A Loud Crash, Then Nothing: Sinkhole Swallows Florida Man. ” CNN, Cable News Network, 5 Mar. 2013, https: //www. cnn. com/2013/03/01/us/florida-sinkhole/index. html. ■ Ellis, Ralph. “Sinkhole Swallows Homes in Florida. ” CNN, Cable News Network, 15 July 2017, https: //www. cnn. com/2017/07/14/us/sinkhole-florida/index. html.

References (Photos) ■ Samal, Himadri. “Evaporites. ” Linked. In Slide. Share, 5 Sept. 2017, https: //www. slideshare. net/Himadri. Samal/evaporites-79462444. (PHOTO)