What is a sinkhole?
A sinkhole is a depression in the ground that has no natural external surface drainage. Basically, this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface.
Sinkholes are most common in what geologists call, “karst terrain.” These are regions where the types of rock below the land surface can naturally be dissolved by groundwater circulating through them. Soluble rocks include salt beds and domes, gypsum, and limestone and other carbonate rock. Florida, for instance, is an area largely underlain by limestone and is highly susceptible to sinkholes.
When water from rainfall moves down through the soil, these types of rock begin to dissolve. This creates underground spaces and caverns.
Sinkholes are dramatic because the land usually stays intact for a period of time until the underground spaces just get too big. If there is not enough support for the land above the spaces, then a sudden collapse of the land surface can occur.
Learn more: USGS Water Science School - Sinkholes
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EarthWord–Karst
Although it sounds like a Batman punch, this EarthWord is closer to the Bat than you’d think...
Karst landscapes are more prone to have land subsidence and sinkholes.
Map of U.S. showing karst areas, which are prone to land subsidence and sinkholes.
The sudden and sometimes catastrophic subsidence associated with localized collapse of subsurface cavities (sinkholes) is detailed in two case studies. This type of sub-sidence is commonly triggered by ground-water-level declines caused by pumping and by enhanced
...Karst, Critters, and Climate Change
This webinar was conducted as part of the Climate Change Science and Management Webinar Series, co-hosted by the USGS National Climate Change and Wildlife Science Center and the FWS National Conservation Training Center. Webinar Description: One-half of North American imperiled species live in subterranean habitats, which largely are associated with karst (a type of
An Unseen World Beneath Our Feet - Caves, Sinkholes and Springs
Randall Orndorff, Director of the Eastern Geology and Paleoclimate Science Center, discusses how Karst affects daily life. Beneath a quarter of the United States are rock types that can dissolve to form caves, sinkholes and other features. Nearly every state has rock layers of limestone, gypsum, and other soluble rocks we call ‘karst’. Karst is important for many reasons.
Karst features, Buffalo National River
Examples of karst features within the Buffalo National River Park. Karst is a type of topography that is formed over limestone, dolomite, or gypsum by dissolving or solution, and that is characterized by closed depressions or sinkholes, caves, and underground drainage (American Geological Institute Dictionary of Geologic Terms).
Sinkholes in West-central Florida, Freeze Event of 2010
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
Sinkholes in West-central Florida, Freeze Event of 2010
Sinkholes affect roadway safety and require constant maintenance and monitoring. More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of
...Sinkholes in West-central Florida, Freeze Event of 2010
The entire root perimeter of this tree collapsed in response to subsidence activity. More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and
...Sinkholes in West-central Florida, Freeze Event of 2010
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.
Sinkhole Activity Damages Home.
Cracking along exterior walls is a sign of subsidence activity. Such severe structural damage from sinkholes can destroy homes and other structures. More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the
...Sinkholes in West-central Florida, Freeze Event of 2010
More than 110 sinkholes formed in the Dover area of Florida during a freeze event in January 2010. Ground water levels dropped to record-setting lows as farmers pumped water to irrigate their plants for protection from the cold temperatures. The sinkholes destroyed homes, roads and sections of cultivated areas.