Sinkholes have opened in recent years across several countries, including Turkey, Chile, Guatemala, and China. The sudden collapse of ground can swallow cars, damage buildings, and destroy roads. While some sinkholes are small, others reach hundreds of feet across and can alter local landscapes permanently.

In Turkey, a sinkhole appeared near the city of Kaç about 65 miles from the city center. It measured approximately 100 feet wide and 50 feet deep. Officials placed warning signs and fences around the area, noting that the ground could still shift further. Experts say the region already contains around 700 sinkholes, and the number is growing. In the past, most appeared in one district, but they have since spread into nearby towns and villages.

Geologists report large empty spaces beneath the surface in this area. Those underground cavities were once filled with water, which helped support the ground above. However, heavy water pumping for farms has contributed to drying out the region. Rainfall has also declined, causing groundwater levels to fall. As the water disappears, the ground above can lose support and collapse.

Turkey also experiences earthquakes. The region sits within a fault-controlled basin, meaning the ground shifts naturally over time. Even small vibrations can trigger a collapse if the surface is already weak. This is one reason sinkholes are appearing more often around the edges of the basin. In some places, underground streams may worsen the problem by carrying loose soil deeper below the surface, creating larger empty spaces.

A large sinkhole also opened at a mining site in Chile. It first measured about 80 feet wide, then expanded to nearly 105 feet across. The hole appeared near an underground copper mine in the Atacama Desert, one of the driest places on Earth. Workers blocked off the area after the collapse was discovered. Geologists arrived to investigate the cause. No one was injured, and the sinkhole did not damage equipment or buildings near the mine. Work underground stopped as a precaution.

In 2010, residents of Guatemala City found a massive sinkhole in the middle of the city. It was about 60 feet wide and around 20 stories deep. Reports indicated the collapse may have swallowed a three-story building. Cars, roads, and nearby infrastructure were pulled into the crater. The ground beneath the city had likely been weakening for weeks or years before the collapse. Tropical Storm Agatha then brought heavy rain to the region, which may have been the final trigger. A damaged sewer or storm drain pipe could have allowed water to leak beneath the city for a long time, weakening the soil. Filling the sinkhole became a difficult operation due to its size.

China is home to one of the largest known sinkholes, called Xiaozhai Tiankeng. It is located in southern China and drops to a maximum depth of about 2,000 feet. It stretches roughly 1,760 feet across. The space is large enough to hold tens of thousands of Olympic swimming pools. A forest exists at the bottom, cut off from the world above. Thick plants cover the ground, and the air stays cool and damp.

This sinkhole formed over thousands of years as rainwater seeped into limestone below the surface, creating tunnels and caves. An underground river carved out even larger spaces. Eventually, the land above collapsed, likely in stages rather than all at once. Because the walls are so deep, sunlight barely reaches the bottom, trapping moisture. Researchers have found more than 12,000 plant species there, including ancient ginkgo trees, giant ferns, and thick mosses. Animals such as clouded leopards have also been observed in the forest at the bottom.

Sinkholes generally form when soft rock, especially limestone, lies below the surface. Rainwater seeps into tiny cracks and gradually erodes the rock. Over time, cracks widen, tunnels form, and empty spaces spread underground. Eventually, the ground becomes thin and weak, then caves in. Some sinkholes are only a few feet deep, while others are as deep as a skyscraper is tall. Many are shaped like funnels, wide at the top and narrow below.

Human activity can make sinkholes worse. Construction, roads, drilling, pipes, and pumping water from underground can weaken the land. Heavy rainfall often becomes the trigger. Around the Dead Sea, the ground contains large amounts of salt, which water dissolves quickly. New sinkholes open frequently in the region, and some have caused injuries to tourists and researchers.

The Band of Holes in Peru is a different kind of ground feature. Thousands of small excavated pits stretch in rows along a mountainside in the Pisco Valley. Aerial photographer Robert Shippy first noticed them in 1931. There are between 5,000 and 6,000 pits, some dug into mounds and others into stone formations. Scientists have found traces of corn and wild plants used for weaving baskets in the area.

Archaeologists also discovered remains of Inca warehouses nearby, along with pottery dating to the 15th century. Around that time, the Inca civilization conquered the Chincha people, who lived on the southwestern coast of present-day Peru. The Incas did not use money. Instead, they collected tribute from conquered peoples through a system of goods exchange. Since they had no scales, they used the pits as a measurement system. Individual Chincha families filled pits with goods such as corn, cotton, and peppers. Inca officials collected the goods and transported them to an administrative center. This system functioned as a form of tax collection about 600 years ago.

The Nazca Lines, also in Peru, remain a subject of archaeological debate. These geoglyphs include over 300 geometric shapes, 800 straight lines, and 70 images of animals and plants. Some figures are as large as the Empire State Building, and some lines extend up to 30 miles. Commercial pilots first identified the full extent of the drawings in the 1930s. The Nazca people, who flourished from around 1 to 700 CE, are believed to have created them. Some archaeologists suggest the images were connected to rituals intended to bring rain, since the region receives very little precipitation. This theory has not been proven.

The Vredefort Crater in South Africa is the largest visible crater on Earth, measuring about 99 miles across. Scientists believe it was once much larger, possibly reaching 174 miles wide before erosion wore it down. The asteroid that created it may have been up to 15.5 miles wide and hit Earth at speeds reaching 56,000 mph. This impact occurred about 2 billion years ago, when Earth was home only to single-celled life. Researchers studied minerals such as quartz and zircon around the crater to estimate the impact’s original size. These minerals contain fractures caused by the blast.

The Wilkes Land anomaly in Antarctica may be an even larger impact crater. Scientists noticed strange gravity readings in the region, including a negative gravity anomaly with a positive anomaly inside it. This structure, called a mascon, often appears where large space rocks have struck the planet. In 2018, researchers mapped the area in detail and found a U-shaped formation. Some scientists believe a meteor up to 30 miles wide created this crater between 4.1 and 3.8 billion years ago. If confirmed, it could be the largest known impact crater on Earth. However, because the crater lies buried under Antarctica’s thick ice sheet, scientists have not ruled out other explanations.

Another gravity mystery involves Hudson Bay in Canada. Researchers first noticed in the 1960s that the region had slightly less gravity than surrounding areas. Two factors explain this. Magma convection deep below the planet’s surface can drag parts of the crust downward, making the area lighter. Additionally, the Laurentide ice sheet, a glacier up to 2.3 miles thick, pressed the land down during the last ice age. Although the ice melted about 10,000 years ago, the land is still slowly bouncing back. This process is called glacial rebound and continues to affect gravity measurements.

Some sinkholes have caused serious damage. In Florida, a sinkhole opened in Highland City near Tampa, appearing in a front yard just inches from a bedroom. In 2013, a sinkhole in Hillsborough County swallowed part of a house while a resident was sleeping. The other five people in the house escaped, but the resident did not survive. The county later purchased the land to prevent anyone from building there again. The sinkhole reopened twice after the initial collapse, but no one was hurt because the area had been cleared. Florida is especially vulnerable because much of its ground consists of carbonate rocks like limestone, which erode easily. Cycles of drought and heavy rainfall weaken the ground further, and rising sea levels raise groundwater levels.

Some sinkholes have become natural attractions. The Dragon Hole in the South China Sea is a blue hole about 984 feet deep, believed to be the deepest in the world. It appeared near the Paracel Islands and is home to over 20 species of fish. The Great Blue Hole in Belize is a popular diving destination, about 480 feet deep. The Hole of Macaúbas in Brazil measures 328 feet deep and serves as a home to thousands of macaws. It formed around 300 million years ago and is now a natural reserve.

Lake Peigneur in Louisiana changed dramatically in 1980 due to a drilling accident. On November 21 of that year, an oil rig drilling in the shallow lake became jammed. Workers tried to free the drill, and the rig began to lean toward the water. The drill had punched a hole into a salt mine beneath the lake, and millions of gallons of water began pouring into the tunnels. Miners evacuated, with 50 people using mine carts and a slow elevator. All of them escaped safely. The water created a large funnel in the lake, pulling in barges, a tugboat, the oil platform, and trees. The surrounding land collapsed into the mine. Within two days, the mine filled completely, and the lake had a new bottom at a depth of about 200 feet. The drilling company paid a $45 million fine for the damage.

Lake Berryessa in California contains a different kind of hole, built intentionally. Engineers constructed a wide concrete tunnel near the lake in the 1950s to handle overflow during rainy seasons. When water levels rise high enough, millions of gallons pour into the hole and travel through a horizontal tunnel into a nearby bay. The structure has become a tourist attraction.

In Yemen, a large hole in the Al Mahra Governorate desert has drawn attention. It measures roughly the size of a basketball court. Locals believe it leads to an underground world where evil spirits live. Scientists have studied the hole with drones and optical lenses but initially could not see the bottom. A group of explorers later descended and found stalactites, snakes, and waterfalls. Some geologists believe the hole formed when drilling operations caused the ground to collapse.

The Arctic has experienced unusual ground formations in recent years. In 2014, a helicopter pilot discovered a crater about 164 feet deep in the permafrost of Siberia’s Yamal Peninsula. More craters appeared in the same area over the next decade. Researchers initially proposed explanations involving meteors or extraterrestrial activity. They later found elevated levels of methane gas around the craters. The Arctic soil contains methane that builds up over time, forming mounds on the surface. When pressure becomes too great, the ground explodes, creating a crater.

The Batagaika Crater in Siberia is another large formation. Satellite images revealed it in 1991, though part of a frozen slope had collapsed in the 1970s. It is the largest mega-slump formation in the world, with an upper rim about 180 feet high. As ice melts, it exposes frozen soil containing fossils, ancient sediments, and DNA from creatures that lived tens of thousands of years ago. In 2018, scientists found a 42,000-year-old foal preserved in the permafrost.

Greenland’s ice has also yielded unexpected discoveries. An ice sample taken in 1993 contained fossils of ancient plants and insects, including moss, willow fragments, and an Arctic poppy. This indicates that at some point in history, the center of Greenland’s ice sheet completely melted. Scientists also found a giant virus in ice samples collected in 2019. This virus is about 100 to 200 times larger than a typical virus and infects algae rather than animals or humans. By darkening the ice, the virus may affect how much light the ice reflects.

The North Anatolian Fault in Turkey has been the subject of recent study. This fault stretches across northern Turkey, where the Eurasian plate and the Anatolian plate slide past each other. In 1939, a rupture caused an earthquake that destroyed around 116,000 buildings and killed over 30,000 people. Since then, researchers have observed that large earthquakes along this fault tend to move westward over time. The section beneath the Sea of Marmara has not had a major earthquake since 1766, which concerns scientists because stress may be building.

Scientists from the Institute of Science Tokyo used electromagnetic imaging to create a three-dimensional map of the fault below the Sea of Marmara. This map showed zones where stress has accumulated. The researchers estimated that the main Marmara fault is already late in its seismic cycle. The area near Istanbul, Turkey’s largest city with around 15 million people, is at risk. Turkey has been upgrading its earthquake early warning system, which can now detect the first seismic waves in about two seconds. In October 2025, the system sent its first alert 8.4 seconds after a magnitude 5 earthquake struck the Sea of Marmara.

The Cascadia Subduction Zone extends from Northern California through Oregon and Washington to Vancouver Island in Canada. This fault has produced major earthquakes in the past, including one in 1700 that sent a tsunami across the Pacific to Japan. Scientists estimate there is roughly a 1 in 8 chance of a Cascadia megaquake within the next 50 years. Such an earthquake could reach magnitude 9 or higher and trigger a tsunami within 15 to 20 minutes. Scientists have detected slow slip events, where tectonic plates move gradually without releasing significant energy storage. GPS stations in 1999 detected ground movement equivalent to a magnitude 6.7 earthquake, but no shaking was felt at the surface.

The Seattle Fault Zone also poses risks. In the winter of 923, an earthquake around magnitude 7.5 caused shorelines to collapse, lifted the seafloor, and triggered a tsunami. Researchers studying marine terraces found that this was the only event of that size in the past 11,000 years. However, smaller faults near Seattle have produced earthquakes more frequently, about every 350 years over the last 2,500 years. These smaller quakes can still damage buildings and infrastructure.

Yellowstone National Park sits on top of an active supervolcano. The park contains over 500 geysers, including Steamboat Geyser and the rare Echinus Geyser. In 2025, scientists noted that the ground near the Norris Geyser Basin had risen by about an inch along the northern rim of the Yellowstone caldera. This type of ground movement has happened before. Between 1996 and 2004, the area south of the basin rose by almost five inches. In late 2013, the ground began rising at a rate of about six inches per year. Neither episode led to an eruption. The last time Yellowstone erupted was about 70,000 years ago. Scientists say the chance of a major eruption is extremely small, and monitoring systems would likely detect warning signs well in advance.

Large igneous provinces are a different type of volcanic hazard. These are areas where the crust leaks lava through long cracks over long periods. About 17 million years ago, the Pacific Northwest experienced such an event, creating the Columbia River Basalt Group. The total amount of erupted material was around 42,000 cubic miles. These eruptions release large amounts of carbon dioxide and sulfur. About 252 million years ago, a similar event in Siberia coincided with the worst extinction event in Earth’s history, during which around 90 percent of species disappeared.

Taftan Volcano in Iran had long been considered extinct, but satellite images have shown its summit rising. Scientists say the movement likely comes from gas or magma pressure below the surface. The source of pressure is located at a depth of about 1,600 to 2,700 feet below the surface, relatively shallow for a volcano. This could produce steam-driven explosions rather than lava flows. No major earthquakes or heavy rains occurred in the area before the movement was detected.