Sinkholes have opened in several parts of the world in recent years, drawing attention to a geological hazard that often develops without visible warning. The ground can hollow out slowly beneath the surface until it eventually collapses, sometimes swallowing vehicles, damaging buildings, and altering landscapes.
A large sinkhole appeared near the Turkish city of Karapinar, roughly 65 miles from the city center. It measured about 100 feet wide and 50 feet deep, and officials placed warning signs and fencing around it because the area remained unstable. The region already contains around 700 sinkholes, and experts say the number is increasing. While they once appeared mainly in one district, they are now spreading into nearby towns and villages.
Geologists say underground cavities in the area were historically filled with water, which supported the ground from below. Heavy water use for farming and declining rainfall have lowered groundwater levels, causing those spaces to empty. When the support disappears, the ground above can collapse without warning. The region is also located in a fault-controlled basin, meaning natural ground movement and small vibrations can trigger a collapse in weak areas. Underground streams may worsen the problem by carrying loose soil deeper, creating larger empty spaces over time.
At a mining site in Chile’s Atacama Desert, a sinkhole opened near an underground copper mine operated by a Canadian company. Initially about 80 feet wide, it later expanded to roughly 105 feet across. Workers blocked off the area, and geologists investigated the cause. No one was injured, and no equipment or buildings were damaged, but underground work was halted as a precaution.
In Guatemala City in 2010, a large sinkhole formed in the middle of the city after Tropical Storm Agatha brought heavy rain. The hole was roughly 60 feet wide and about 20 stories deep. It destroyed a three-story building and damaged roads and infrastructure. Investigators believed water from broken sewer or storm drain pipes had weakened the soil underground for a long time, and the heavy rainfall acted as the final trigger.
Some sinkholes become notable for their size. A sinkhole in southern China called Xiaozhai Tiankeng is about 2,000 feet deep and 1,760 feet across. It formed over thousands of years as rainwater dissolved limestone, creating tunnels and caves beneath the surface. A powerful underground river carved out even larger spaces, and eventually the land above collapsed. The hole has two levels, suggesting different sections gave way at different times. Its depth and humid conditions have created a unique ecosystem at the bottom, with more than 12,200 plant species, including ancient ginkgo trees and giant ferns, as well as animals such as clouded leopards.
Sinkholes can also form near the Dead Sea, where the ground contains large amounts of salt that dissolve quickly in water. New holes open across the region, and some have caused injuries to people nearby.
The Arctic has seen a different kind of ground collapse. Large craters have appeared in the permafrost since 2014, and researchers initially struggled to explain them. They eventually identified elevated methane gas levels around the craters. Methane builds up in the soil over time, forming mounds on the surface. When pressure becomes too great, the ground explodes, leaving a crater. Later research suggested the process involves cryopegs, pockets of super-salty unfrozen water between the permafrost and deeper methane layers. As ice melts, water seeps into these pockets, creating pressure that fractures the ground above and eventually cracks the methane layer, causing an explosion.
The Arctic has also produced the Batagaika Crater, a large depression in Siberia that scientists call a mega-slump. It formed when part of a frozen slope collapsed, exposing layers of soil that had been frozen for hundreds of thousands of years. The site has yielded preserved fossils, including a 42,000-year-old horse, and it continues to grow as ice melts.
Greenland has offered a different kind of discovery. An ice sample taken in 1993 and stored in a lab for 30 years was found to contain fossils of ancient plants and insects, including moss, willow fragments, and an Arctic poppy. These findings indicate that the center of Greenland’s ice sheet once melted completely, allowing an ecosystem to develop. Researchers say the discovery raises questions about potential future melting.
Scientists have also found a giant virus in Greenland’s ice. It infects algae and may help reduce ice melting by darkening the ice, which affects how much light it reflects. The virus is about 100 to 200 times larger than a typical virus, and researchers are working to understand its behavior.
A massive impact crater beneath the ice in Antarctica has attracted scientific attention. The Wilkes Land anomaly shows unusual gravity patterns, including a negative gravity anomaly with a positive anomaly at its center, a structure often associated with meteor impacts. Some scientists believe a meteor up to 30 miles wide struck the region between 4.1 and 3.8 billion years ago, leaving behind one of the largest impact craters on Earth. The crater is difficult to study because it lies under thick ice, and researchers have not ruled out other explanations, such as volcanic activity or sedimentary basins.
Canada’s Hudson Bay region has also puzzled scientists with a gravity anomaly. Measurements taken since the 1960s show gravity is slightly weaker there than elsewhere. Two factors appear to explain the difference. Magma movement deep underground is dragging parts of Earth’s crust downward, reducing mass. Additionally, the Laurentide Ice Sheet, a massive glacier that covered the area during the last ice age, pressed the land down. The land is still slowly rising as it recovers, a process called glacial rebound, which will continue for thousands of years.
In the United States, Florida has experienced numerous sinkholes because the state sits on carbonate rocks such as limestone, which erode easily. Cycles of drought and heavy rain weaken the ground further, and rising sea levels are pushing groundwater higher. In 2013, a sinkhole opened beneath a home in Hillsborough County, swallowing part of the house. One person died in the incident. The county purchased the land and surrounding properties to prevent further construction. The sinkhole reopened twice after the initial collapse, but no one was hurt because the area had been cleared.
A sinkhole in the sea near the Paracel Islands has become a point of interest for divers. Known as the Dragon Hole, it is about 984 feet deep and is believed to be the deepest blue hole in the world. Blue holes form underwater when limestone dissolves and creates cavities that eventually collapse. The Dragon Hole may have formed through tectonic activity or other geological events, and it supports more than 20 species of fish.
In Brazil, a sinkhole called the Hole of Macaúbas is about 328 feet deep and serves as a natural reserve for thousands of macaws. It formed through limestone erosion around 300 million years ago.
Louisiana’s Lake Peigneur experienced a human-caused disaster in 1980. An oil rig drilling in the shallow lake struck a salt mine, causing millions of gallons of water to pour into the mine tunnels. The rig, barges, a tugboat, and the surrounding beach were pulled into the expanding funnel. All miners were evacuated safely. The lake’s bottom dropped to about 200 feet, and the ecosystem changed completely. An investigation found that an engineer made an error in the maps used to select drilling coordinates. The drilling company paid $45 million in damages.
In California, Lake Berryessa has a different kind of hole. A concrete spillway was built in the 1950s to handle excess water during the rainy season. The structure, known as the Glory Hole, is a wide circular tunnel that drains water into a nearby bay when the lake level rises. It has become a popular tourist attraction, and skateboarders sometimes use the tunnel when water levels are low.
A large hole in the desert of Yemen has drawn curiosity and fear. The site, roughly the size of a basketball court, is surrounded by local legends about evil spirits. Strange sounds and a smell of rotten eggs come from the hole, which is so dark that light does not penetrate it. Researchers have descended to the bottom and found stalactites, snakes, and waterfalls. Scientists are still investigating how the hole formed and how old it is.
The Mariana Trench is the deepest known pit on Earth, located in the western Pacific Ocean. It is deep enough to fit about one and a half Mount Everests. Pressure at the bottom is extreme, but unique creatures live there, including microorganisms that feed on oily substances, fish with transparent bodies, and other species adapted to the environment.
Earthquakes remain a separate and more immediate concern in several regions. Turkey has been preparing for a potential major earthquake near Istanbul. The North Anatolian Fault runs beneath the Sea of Marmara, and historical records suggest large earthquakes in the region have repeated roughly every 250 years. The last major quake was in 1766. Studies show the fault has areas that move slowly and one locked section south of Istanbul that builds stress without releasing it through small shakes. Researchers have developed a new 3D map of the fault using electromagnetic imaging, which helps identify where stress has accumulated. Turkey has also upgraded its earthquake early warning system, which can detect initial seismic waves in about two seconds, though underwater sensors are still limited.
Scientists studying the Marmara fault have used simulations to better understand how it behaves. They found that the fault does not rupture all at once like a single zipper. Instead, it breaks in sections, and the sequence of events is shaped by rock behavior under heat and pressure. In the western segments, smaller earthquakes occur regularly, while the eastern sections produce occasional moderate quakes. Parts of the fault creep slowly without producing major events. The simulations suggest a significant earthquake could occur in the coming decades, but they estimate the maximum likely magnitude at around 7.3, not the higher range some earlier models suggested.
Santorini experienced a swarm of more than 28,000 earthquakes in early 2025. Most were small, but some reached magnitude 5, causing schools to close and parts of the island to be evacuated. The epicenters shifted gradually toward the Columbo submarine volcano offshore, indicating that magma was moving. Researchers calculated that roughly 80 billion gallons of magma surged upward from deep underground and stalled a few miles below the seafloor. This type of activity changes the stress fields underground and can affect future seismic behavior.
The Cascadia Subduction Zone, which runs from Northern California to Vancouver Island, has the potential to produce a very large earthquake. The fault has been quiet for centuries, and scientists worry that pressure has been building. The last major event occurred in 1700 and triggered a tsunami that reached Japan. Studies suggest there is about a one in eight chance of a magnitude 9 earthquake in the next 50 years. Such an event could cause severe shaking, landslides, and a tsunami reaching coastal areas within 15 to 20 minutes. Parts of the coastline could drop by several feet. Scientists are working to improve monitoring systems, including installing sensors on a fiber optic cable off the coast of Oregon.
The Seattle Fault Zone presents a more localized risk. A magnitude 7.5 earthquake occurred in the Seattle area in the year 923, causing shorelines to collapse and a tsunami to sweep through Puget Sound. New research indicates that large quakes of that size are rare, but smaller earthquakes occur more frequently than previously thought. These smaller quakes can still damage buildings and infrastructure. Scientists are working to update seismic hazard models to account for these risks.
California’s San Andreas Fault is another major concern. The fault spans about 800 miles and has a long history of strong earthquakes, including the 1906 San Francisco earthquake. Some scientists now believe the San Andreas Fault and the Cascadia Subduction Zone may be linked. Marine sediment cores suggest paired earthquakes have occurred in both zones at least 10 times in the last 3,100 years. A rupture in one fault can increase stress on the other, potentially leading to a second earthquake soon after the first. The two faults meet near the Mendocino Triple Junction, where three tectonic plates interact.
The 1995 Kobe earthquake in Japan demonstrated how disruptive a major seismic event can be. The magnitude 7.2 quake killed more than 5,000 people and caused about $200 billion in damage. It exposed weaknesses in older buildings and infrastructure, and Japan overhauled its disaster management system afterward. The country introduced stricter building codes and a national earthquake early warning system that has been credited with saving lives since 2007.
Yellowstone, often the subject of doomsday speculation, has shown signs of activity that scientists say are not unusual. The ground near the Norris Geyser Basin has risen and fallen in cycles since the 1990s, driven by magma movement deep underground. A rare acidic geyser called Echinus erupted in February 2026 after being quiet for six years, and the number of small earthquakes increased in late 2025. Scientists say these changes are small compared to the warning signs they would expect before a major eruption. The magma chamber beneath Yellowstone is only about 5 to 15 percent liquid, and researchers do not believe an eruption is imminent. The last major eruption occurred about 631,000 years ago.
A dormant volcano in Iran has shown signs of renewed activity. Taftan Volcano, located in the southeastern part of the country, has seen its summit rise by about 3.5 inches over a ten-month period. Scientists reclassified it from extinct to dormant after satellite images showed the ground moving. They believe pressure from gas or magma below the surface is causing the uplift, and the pressure source sits relatively close to the surface. Steam-driven explosions are a concern, even without flowing lava. The volcano produces sulfur dioxide emissions that can affect air quality and spread with the wind. Because Taftan is in a remote area, monitoring relies primarily on satellites.
In Yellowstone and other volcanic regions, researchers remain watchful but not alarmed. The Yellowstone alert level is green, and scientists say the current activity is consistent with normal behavior for the region. They continue to monitor the area closely, but they see no signs of an imminent eruption.
