The largest sinkhole in the world is the Qattara Depression near Cairo, Egypt. The sinkhole, which is filled with sludge and quicksand, measures almost 50 miles (80 kilometers) long and 74 miles (120 kilometers) wide. The depression covers an area of about 7,000 square miles (18,130 square kilometers) — about the size of Lake Erie.
More Sinking Facts:
- Another large sinkhole in the world just keeps on growing. The sinkhole near Berezniki, Russia, got started in 1986 and keeps getting bigger every year. It measures more than 656 feet (200 meters) deep, 262 feet (80 meters) long and 131 feet (40 meters) wide. If the sinkhole gets much bigger, it will threaten the rail lines coming from one of the world's biggest potassium carbonate, or potash, mines.
- One of the more recent sinkholes to develop is one located in Guatemala City, Guatemala, where a sinkhole suddenly swallowed a three-story building. Geologists believe this sinkhole was the result of human activity — burst pipes may have been eroding the ground under the city, which is mostly comprised of pumice from previous volcano eruptions. In fact, because the ground below was not solid bedrock, this hole, may not technically be a sinkhole. The hole is about 300 feet (100 meters) deep and 60 feet (18 meters) wide.
- One sinkhole in 2008 threatened to swallow an entire town in Texas. Daisetta, Texas, was built over a salt dome and several small sinkholes have developed from collapses in the salt dome since the town was established. The 2008 sinkhole, however, grew to 600 by 500 feet (180 by 160 meters) with a depth of about 150 feet (45 meters). Local officials still see the sinkhole as a threat to the town.