Yellowstone National Park is situated atop an active supervolcano

Many believe a cataclysmic volcanic eruption is imminent at Yellowstone, though experts say it is unlikely

Mike Poland, a scientist at the Yellowstone Volcano Observatory, estimates the likelihood of the event at one in a million. He cautions, though, that the park poses other potential dangers, including steam explosions and earthquakes.

The average eruption cycle of the Yellowstone supervolcano is 735,000 years

Eruptions a little over 2 million, 1.3 million, and 630,000 years ago indicate that the eruption is not imminent, though the sample size is small. Recent analysis reveals magma pockets are not interconnected, reducing eruption risk.

Yellowstone was the world's first national park

Before it was designated as such, it was home to 27 Indigenous tribes, including the Blackfeet, Crow, and Nez Perce. European trappers and traders traveling west were entranced by the area’s stunning beauty and natural resources, fueling a push for the government to preserve the land for future generations.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Volcanoes can be active, dormant, or extinct based on the recency of eruptions

Active volcanoes may be in the process of erupting or expected to erupt in the future, having done so within the past 11,650 years. Dormant volcanoes have no short-term eruption history, but are expected to erupt in the future, while extinct volcanoes lack the history and expectation.

Supervolcanoes can eject enough material to fill one-fourth of the Grand Canyon

Although extremely rare, their released material can trigger winters by blocking the sun and cooling the Earth’s surface for years. The Toba supereruption 74,000 years ago disrupted food chains and reduced the human population to a few thousand.

View a gallery of diagrams for each volcano type with glossaries

The three major types of volcanoes—cinder cone, composite, and shield—each exhibit unique, lesser-known subterranean and surface features, including lava bombs, lahars, and spatter. Other types of volcanoes include lava domes, calderas, fissure volcanoes, and Maars and tuff rings.

The volcano threatening the Greek island of Santorini

Santorini is a popular tourist destination, known for its stunning white architecture and dreamy blue waters. Yet underneath the charming island is a potentially dangerous underwater volcano. Recent earthquakes have triggered nearly half of residents to evacuate, signaling heightened uncertainty about when the volcano could erupt. Researchers studying activity in the region plan to produce detailed hazard maps for Greek authorities to improve local safety and emergency planning.

The Geysers is the largest geothermal power complex in the world

Despite the Mayacamas Mountains area north of San Francisco lacking geysers, the name given by a grizzly bear hunter stuck after the construction of The Geysers Resort Hotel to accommodate tourists. Natural steam vents in the region are funneled into more than 12 geothermal plants, each capable of powering about 40,000 homes.

Explosive volcanic eruptions happen when magma pressure overcomes rock strength

Magma usually stays underground because of a balance between its upward pressure, the weight of the Earth’s crust above, and the crust’s rock strength. Landslides can reduce crust weight, while built-up gas pressure can strengthen magmastatic pressure.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Great Smoky Mountains National Park is the most popular national park

The Tennessee park attracted more than 12 million visitors in 2024, nearly three times the amount Zion National Park, the number two most popular park, brought in. The least visited park was the famously remote Gates of the Arctic National Park and Preserve in Alaska, which posted only 11,907 visitors.

Human activities release 100 times the carbon dioxide of all volcanic eruptions

While gases released by volcanoes contribute to climate change, humans produce the carbon dioxide equivalent of a Mount St. Helens-sized eruption every 2.5 hours, or more than one Yellowstone eruption yearly, even though such supervolcanoes only erupt about every 100,000 to 200,000 years or more.

A nearby super volcano poses an even greater risk to Italy than Vesuvius

The Campi Flegrei supervolcano, with over half a million residents nearby, may be the region’s true threat. This BBC short shows how scientists monitor Campania’s volatile geology—and why people remain drawn to the landscape despite the danger.

National parks, explained

Roughly 83 million acres of the United States are set aside as federal National Parks land, an area large as Germany. From the original Yellowstone Park to small monuments and memorials, learn the essentials on this portion of America dedicated to public enjoyment and recreation with our quick explainer video.

Located on Ross Island in Antarctica, Mount Erebus is the southernmost active volcano on Earth and features a lava lake—one of eight known worldwide as of 2026—that erupts regularly.

Vesuvius has erupted nearly 40 times since Pompeii

With a 17,000-year history and dozens of eruptions since 79 CE, Vesuvius sits atop volatile geological forces that make it an unusually explosive volcano. This explainer breaks down why the volcano remains dangerous today.

See Mount Vesuvius from space

Mount Vesuvius is one of the few active volcanos on Europe's mainland. See it from space in this photo from NASA's Earth Observatory. This natural-color image was taken on January 2, 2022, during a break in cloud coverage.

Eruption forecasting relies on probabilistic methods resembling weather forecasting

While some volcanoes erupt with predictable signs, such as surface deformation from the build-up of underground magma pressure, others release magma at inconsistent rates. Extensive monitoring is needed to identify less clear patterns and indicators of future eruptions.

Visit global national parks from your living room

Get your fill of incredible scenery with this collection of 17 different virtual tours of national parks. Catch the Northern Lights over Abisko National Park in Sweden, or explore the famous red sand dunes of Namib-Naukluft National Park in Namibia.

Most volcanic activity occurs in submarine volcanoes on the seafloor

At divergent plate boundaries in mid-ocean ridges, volcanic activity produces new ocean crust as the seafloor spreads. These areas are home to underwater mountains with extensive biodiversity due to redirecting ocean currents and concentrating food for marine life.

A volcanic island north of Sicily is the world's longest continuously active volcano

Stromboli has been releasing lava for at least 2,000 years, with the earliest recorded eruption dating back to 350 BCE. Its mild but ongoing bursts of bright lava have earned it the nickname, "lighthouse of the Mediterranean."

The creation of the parks often involved displacing Native tribes

Early parks like Yellowstone, Glacier, and Yosemite involved the removal of tribal communities like the Shoshone, Crow, and Nez Percé, undermining the popular narrative that parks preserved an uninhabited wilderness.

Cerulean eruptions result from sulfur being heated by molten rock

During eruptions, warm-colored lava at temperatures between 700 and 1,200 degrees Celsius (1,300 and 2,200 degrees Fahrenheit) burns minerals as they escape from underground reservoirs. In some volcanoes, such as Indonesia's Kawah Ijen and Ethiopia's Danakil Depression, abundant sulfur compounds that burn with blue flames appear to change the color of the melted rock.

Rainfall and lush vegetation make the Great Smoky Mountains smoky

The national park is a rainforest that receives significant rainfall. When the vegetation on the mountains gets wet, it releases a gas that is smoky, and sometimes even appears blue, a phenomenon that gave the mountains (and the park) its name.

The 52-mile marvel of engineering inside Glacier National Park

Glacier National Park is home to over one million acres of natural beauty, but it also includes 52 miles of a manmade miracle in Going-to-the-Sun Road, which takes drivers on a majestic tour through some of the park's most breathtaking views. This brief history and photo gallery allows you to gain an appreciation for the incredible engineering behind the road’s construction.

National parks require numerous items of interest

To be designated a national park, an area must have various scenic, inspirational, educational, and recreational items of interest. A national monument designation requires only one item of interest and is usually reserved for smaller areas with particular historical, cultural, and/or scientific relevance.

Explore landforms that exist across America's national parks

Landforms are not just scenic vistas; they are geological storytellers that shape ecosystems, climates, and our understanding of Earth's history. In this comprehensive look at landforms from the National Park Service, you will learn not only about different types of American landforms, but you will understand how these geological features are shaped by various forces, how they reveal an area's geological history, and how they influence climate and ecology.

A look at hydrothermal vents, where barophiles and hyperthermophiles survive boiling water

Discovered in 1977 during an exploration of the Galapagos Rift, these seafloor openings spew hot magma and chemicals that heat seawater to hundreds of degrees. Without the sunlight found at depths of less than 1,000 meters (3,281 feet), extremophiles in these environments convert released chemicals into energy to survive, alongside surviving extreme pressures.

The National Parks System is a popular attraction in the US

More than 16 billion people have visited the US National Park System since 1904. Curious about how something like World War II affected park visitation? This table of annual recreational visits spans the early 20th century through 2023, demonstrating the slow-but-steady rise in visitors over the decades.

With a height three times that of Mount Everest and an area roughly the size of Poland, the Martian shield volcano Olympus Mons is the largest volcano in the solar system.

Every type of US national park, explained

Ever wonder what kinds of sites comprise the US National Park System? Using the recent re-designation of New River Gorge as a national park as a jumping-off point, this engaging video breaks down the 19 different designations within the National Park System. This includes parks, reserves, monuments, and scenic trails.

The Ring of Fire, which spans 40,000 kilometers (24,900 miles) around the Pacific Ocean, is the most geologically active region on Earth.

Listen to a podcast about the eerie side of national parks

Although the National Park System is a relatively recent invention, the lands it includes have been around since the dawn of time and, as a result, have accumulated some interesting folklore. This podcast walks you through some of the best legends about the parks.

Could we throw trash inside volcanoes?

Americans toss out about 239 million tons of garbage each year. Some have wondered whether we could toss some (or all) of it into volcanoes, where it could be destroyed. There are about 1,500 active volcanoes on Earth, and many are pretty remote, making logistics complex. This video investigates whether the idea checks out.

Lava flow viscosity plays a significant role in the type of volcano formed

Thin, runny flows spread quickly before cooling, producing expansive layers that build over time into wide shield volcanoes. The ejection and fast hardening of thicker lava flows and pyroclastic material create steep slopes and the characteristic cone shape of composite volcanoes.

Mapping the Tongan eruption impact

A team of scientists—with the help of an uncrewed boat remotely controlled from the UK—join forces to produce one of the clearest pictures to date of what took place underneath the water as an enormous volcano erupted near the Tongan mainland.

The National Parks System includes 63 parks and 400 smaller preserved sites

Want to see how close you are to one of the major preserves or lesser-known historic sites? Explore this interactive map from the National Park Service to plan your next adventure to protected, historic land.

Ansel Adams' 20th-century photographs of national parks captured the majesty of a growing National Park System.

Extraterrestrial volcanoes spew material present during their formation

Unlike Earth's volcanoes that release lava, cryovolcanoes on distant moons erupt cold jets of water, ammonia, and other light gases present during the formation of their host planet. The movement of internal heat produced during formation is thought to drive icy plume movement.

The continuous decay of radioactive elements regenerates geothermal energy reserves

Geothermal power is a renewable energy source derived from Earth's interior, where the core reaches temperatures exceeding 5,000 degrees Celsius (9,000 degrees Fahrenheit). These temperatures result from leftover energy from collisions during planetary formation, with radioactive decay in the core releasing additional energy that travels to the surface.

The list of historic volcanic eruptions includes the 1883 blast from Krakatau, which killed more than 36,000 and was the first such event to be documented in real time, thanks to the telegraph.

In 2009, accidentally drilling into magma provided time capsules of volcanic glass

While drilling for geothermal energy in Iceland's Krafla Geothermal Field, magma encountered at a depth of 2,100 meters quickly formed glass upon making contact with drilling fluid. By trapping dissolved gases, volatile chemicals, and the physical characteristics of magma before cooling, the glass acts as a time capsule of ancient volcanic activity and magmatic conditions.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

Watch city kids encounter the national parks

Part of Ken Burns’ "The National Parks: America’s Best Idea" film series, this video follows students from Las Vegas and Miami as they visit national parks. In Death Valley, the students get hands-on lessons in geology, while in Biscayne, they canoe through secluded groves and past coral reefs.

Explore an interactive map of volcanoes, earthquakes, and tsunamis from 2150 BCE to the present.

Scientists monitor volcanoes with a suitcase-sized observatory called SKATE

Short for Setup for the Kinematic Acquisition of Explosive Eruptions, the device is left to record heat, sound and visual data while volcanologists remain at a safe distance. The $58,000 tool is the successor to the FAMoUS (Fast Multiparametric Setup) prototype.

Humans were forced to adapt to survive a supervolcano eruption 74,000 years ago

The Toba supereruption ejected 2800 cubic kilometers of ash, resulting in global cooling from blocked sunlight and acid rain. Archaeological sites show that humans developed bow-and-arrow technology to survive in arid conditions by fishing in seasonal waterholes.

The composition of magma affects the explosivity of volcanic eruptions

Silicate-rich magma contains extensive molecular chains that trap dissolved gases like water and carbon dioxide. These gases build pressure until they violently escape, creating explosive eruptions. Low-silica magmas produce gentler eruptions categorized as effusive.

View maps of seafloor topography, earthquakes, and volcanic activity, which scientists use to create outlines of Earth's tectonic plates.