Map of U.S. showing karst areas, which are prone to land subsidence and sinkholes.
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, 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:
Related
How many sinkholes open up in a year?
There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state. Many sinkhole collapses are not reported to authorities or news organizations, and many occur in rural areas where they are unobserved. Learn more: USGS Water Science School - Sinkholes Karst Map of the Conterminous...
How much does sinkhole damage cost each year in the United States?
Sinkhole damages over the last 15 years cost on average at least $300 million per year. Since there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost. Learn more: USGS Water Science School - Sinkholes Karst Map of the Conterminous United States - 2020
What is the difference between a sinkhole and a pothole?
A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void. A pothole is usually a fairly small feature caused by failure of paving materials, usually associated with roads, parking lots, and airports. In the colder parts of the country, potholes become more abundant...
What is the difference between a sinkhole and land subsidence?
Sinkholes are just one of many forms of ground collapse, or subsidence. Land subsidence is a gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials. The principal causes of land subsidence are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. Land...
What is the largest sinkhole in the United States?
There are some very large, ancient, ‘inactive’ sinkholes in some areas of the U.S. that are thousands of years old. Alabama claims to have the largest recent collapse sinkhole. It is called the “Golly Hole” and is located in Shelby County in the central part of the state. It collapsed suddenly in 1972. The sinkhole is about 325 feet long, 300 feet wide, and 120 feet deep. Learn more: USGS Water...
Why are there no entries for caves in the Geographic Names Information System database?
Geographic Names Information System (GNIS) does include caves but the entries are not publicly available. In response to the 1988 National Cave Management Resources Act, Department of the Interior Regulation 43 (CFR Subtitle A, Part 37) forbids the release of information regarding the location of all caves on Federal lands. Currently, GNIS does not distinguish between features on Federal versus...
I have (or think I have) a sinkhole on my property. What should I do?
While the USGS studies the types of rocks that can potentially form sinkholes, we don’t investigate individual sinkholes on private property. First, rule out human causes for your feature. Some sinkholes are caused by leaky underground pipes (talk to your utility company) and some are old construction pits or other buried materials that have settled. If you’re confident of a natural cause for your...
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.
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.
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.
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’.
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’.
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.
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.
Cracking along exterior walls is a sign of subsidence activity. Such severe structural damage from sinkholes can destroy homes and other structures.
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.
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
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 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.
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.
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.
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.
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.
What are sinkholes?
Listen to hear the answer.
What's Up With Sinkholes?
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
Various Karst Features Along Peace River, Fl
Observing the small amount of flow going into Dover Sink.
Observing the small amount of flow going into Dover Sink.
Various Karst Features Along Peace River, Fl
Monitoring levels at Gator Sink.
Monitoring levels at Gator Sink.
Various Karst Features Along Peace River, Fl
Crevasses Sink spans approximately 25 ft across the river bed.
Crevasses Sink spans approximately 25 ft across the river bed.
Winter Park Florida Sinkhole of 1981
Photo 15 of 15: Water level in sinkhole chimney stabilized since the previous day. View to south across the sinhole.
Photo 15 of 15: Water level in sinkhole chimney stabilized since the previous day. View to south across the sinhole.
Winter Park Florida Sinkhole of 1981
Photo 5 of 15: House in a sinkhole. View to east across the sinkhole.
Photo 5 of 15: House in a sinkhole. View to east across the sinkhole.
Winter Park Florida Sinkhole of 1981
Photo 6 of 15: Sinkhole chimney at approximately 12 noon. View to south across the sinkhole.
Photo 6 of 15: Sinkhole chimney at approximately 12 noon. View to south across the sinkhole.
Winter Park Florida Sinkhole of 1981
Photo 12 of 15: Water level has risen and is now apparent in sinkhole since pool collapse and house swallowed. View to south across the sinkhole. The rising water level is likely a result of the debris plugging the conduit into the Floridan aquifer. Water level is rising to assume a position more consistent with that of the surficial aquifer. (3 p.m.)
Photo 12 of 15: Water level has risen and is now apparent in sinkhole since pool collapse and house swallowed. View to south across the sinkhole. The rising water level is likely a result of the debris plugging the conduit into the Floridan aquifer. Water level is rising to assume a position more consistent with that of the surficial aquifer. (3 p.m.)
Sinkhole in Frederick, Maryland
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Prairie Pothole Region
Prairie Pothole Region landscape showing high wetland density.
Prairie Pothole Region landscape showing high wetland density.
Related
How many sinkholes open up in a year?
There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state. Many sinkhole collapses are not reported to authorities or news organizations, and many occur in rural areas where they are unobserved. Learn more: USGS Water Science School - Sinkholes Karst Map of the Conterminous...
How much does sinkhole damage cost each year in the United States?
Sinkhole damages over the last 15 years cost on average at least $300 million per year. Since there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost. Learn more: USGS Water Science School - Sinkholes Karst Map of the Conterminous United States - 2020
What is the difference between a sinkhole and a pothole?
A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void. A pothole is usually a fairly small feature caused by failure of paving materials, usually associated with roads, parking lots, and airports. In the colder parts of the country, potholes become more abundant...
What is the difference between a sinkhole and land subsidence?
Sinkholes are just one of many forms of ground collapse, or subsidence. Land subsidence is a gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials. The principal causes of land subsidence are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. Land...
What is the largest sinkhole in the United States?
There are some very large, ancient, ‘inactive’ sinkholes in some areas of the U.S. that are thousands of years old. Alabama claims to have the largest recent collapse sinkhole. It is called the “Golly Hole” and is located in Shelby County in the central part of the state. It collapsed suddenly in 1972. The sinkhole is about 325 feet long, 300 feet wide, and 120 feet deep. Learn more: USGS Water...
Why are there no entries for caves in the Geographic Names Information System database?
Geographic Names Information System (GNIS) does include caves but the entries are not publicly available. In response to the 1988 National Cave Management Resources Act, Department of the Interior Regulation 43 (CFR Subtitle A, Part 37) forbids the release of information regarding the location of all caves on Federal lands. Currently, GNIS does not distinguish between features on Federal versus...
I have (or think I have) a sinkhole on my property. What should I do?
While the USGS studies the types of rocks that can potentially form sinkholes, we don’t investigate individual sinkholes on private property. First, rule out human causes for your feature. Some sinkholes are caused by leaky underground pipes (talk to your utility company) and some are old construction pits or other buried materials that have settled. If you’re confident of a natural cause for your...
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.
Map of U.S. showing karst areas, which are prone to land subsidence and sinkholes.
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.
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.
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’.
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’.
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.
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.
Cracking along exterior walls is a sign of subsidence activity. Such severe structural damage from sinkholes can destroy homes and other structures.
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.
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
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 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.
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.
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.
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.
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.
What are sinkholes?
Listen to hear the answer.
What's Up With Sinkholes?
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
A huge sinkhole in Texas begs a few questions about this fascinating and sometimes hazardous phenomenon, so we sit down with USGS geologist Randy Orndorff to learn more.
Various Karst Features Along Peace River, Fl
Observing the small amount of flow going into Dover Sink.
Observing the small amount of flow going into Dover Sink.
Various Karst Features Along Peace River, Fl
Monitoring levels at Gator Sink.
Monitoring levels at Gator Sink.
Various Karst Features Along Peace River, Fl
Crevasses Sink spans approximately 25 ft across the river bed.
Crevasses Sink spans approximately 25 ft across the river bed.
Winter Park Florida Sinkhole of 1981
Photo 15 of 15: Water level in sinkhole chimney stabilized since the previous day. View to south across the sinhole.
Photo 15 of 15: Water level in sinkhole chimney stabilized since the previous day. View to south across the sinhole.
Winter Park Florida Sinkhole of 1981
Photo 5 of 15: House in a sinkhole. View to east across the sinkhole.
Photo 5 of 15: House in a sinkhole. View to east across the sinkhole.
Winter Park Florida Sinkhole of 1981
Photo 6 of 15: Sinkhole chimney at approximately 12 noon. View to south across the sinkhole.
Photo 6 of 15: Sinkhole chimney at approximately 12 noon. View to south across the sinkhole.
Winter Park Florida Sinkhole of 1981
Photo 12 of 15: Water level has risen and is now apparent in sinkhole since pool collapse and house swallowed. View to south across the sinkhole. The rising water level is likely a result of the debris plugging the conduit into the Floridan aquifer. Water level is rising to assume a position more consistent with that of the surficial aquifer. (3 p.m.)
Photo 12 of 15: Water level has risen and is now apparent in sinkhole since pool collapse and house swallowed. View to south across the sinkhole. The rising water level is likely a result of the debris plugging the conduit into the Floridan aquifer. Water level is rising to assume a position more consistent with that of the surficial aquifer. (3 p.m.)
Sinkhole in Frederick, Maryland
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Cover-collapse sinkhole in limestone near Frederick, Maryland (September 2003). Many sinkholes occur along highways where rainwater runoff is concentrated into storm drains and ditches increasing the rate of sinkhole development (note the sewer drain pipe beneath roadway).
Prairie Pothole Region
Prairie Pothole Region landscape showing high wetland density.
Prairie Pothole Region landscape showing high wetland density.
Updated Date: February 4, 2025