The Florida peninsula is a porous plateau of karst limestone sitting atop bedrock known as the Florida Platform.
The emergent portion of the platform was created during the Eocene to Oligocene as the Gulf Trough filled with silts, clays, and sands. Flora and fauna began appearing during the Miocene. No land animals were present in Florida prior to the Miocene.
The largest deposits of potash in the United States are found in Florida.
Extended systems of underwater caves, sinkholes and springs are found throughout the state and supply most of the water used by residents. The limestone is topped with sandy soils deposited as ancient beaches over millions of years as global sea levels rose and fell. During the last glacial period, lower sea levels and a drier climate revealed a much wider peninsula, largely savanna. The Everglades, an enormously wide, very slow-flowing river encompasses the southern tip of the peninsula. Sinkhole damage claims on property in the state exceeded a total of $2 billion from 2006 through 2010.
Florida is tied for last place as having the fewest earthquakes of any US state. Because Florida is not located near any tectonic plate boundaries, earthquakes are very rare, but not totally unknown.
In January, 1879, a shock of Mercalli intensity scale VI occurred near St. Augustine. There were reports of heavy shaking that knocked plaster from walls and articles from shelves. Similar effects were noted at Daytona Beach 50 miles (80 km) south. The tremor was felt as far south as Tampa and as far north as Savannah, Georgia.
In January 1880, Cuba was the center of two strong earthquakes that sent severe shock waves through the city of Key West, Florida.
The shock from the 1886 Charleston, South Carolina, earthquake was felt throughout northern Florida, ringing church bells at St. Augustine and severely jolting other towns along that section of Florida's east coast. Jacksonville residents felt many of the strong aftershocks that occurred in September, October, and November 1886.
In 2006, a magnitude 6.0 earthquake centered about 260 miles (420 km) southwest of Tampa in the Gulf of Mexico sent shock waves through southwest and central Florida. The earthquake was too small to trigger a tsunami and no damage was reported.
The 1755 Lisbon earthquake triggered a tsunami that would have struck Central Florida with an estimated 1.5 metres (4 ft 11 in) wave.