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.

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.

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.

Volcanic ash is composed of fragments of volcanic rock, minerals, and glass

These abrasive particles are hazardous to aircraft. They can melt within engines and re-solidify on turbine blades, preventing forward propulsion. If inhaled, chemicals within ash can be toxic, and the particles can embed themselves into the lungs' ducts, causing suffocation.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

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.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

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.

New evidence suggests the eruption's victims died as their blood boiled

While most Pompeii victims suffocated or were crushed, spectroscopic analysis of bones from a nearby town indicates something more extreme: exposure to superheated gas that instantly boiled blood and caused deadly internal trauma.

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.

How powerful was the volcanic blast that destroyed parts of ancient Rome?

This article details how strong Mt. Vesuvius' powerful 79 CE blast may have been. Pompeii lay a bit further from the volcano's slopes than Herculaneum, a smaller seaside city. While Pompeii was mainly destroyed by ash and lapilli—glassy fragments of lava ejected during volcanic eruptions—Herculaneum was first hit by a scorching pyroclastic cloud of volcanic gas and other matter.

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.

View the 10 biggest volcanic eruptions in recorded history

The Mount Tambora eruption in 1815 was the deadliest and released so much sun-blocking ash and gas that 1816 became known as “the year without summer.” The resulting global food shortages are estimated to have killed over 71,000 people.

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.

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."

If the Earth stopped spinning, 85% of the world's population would experience supersonic winds

The planet's equator moves about 470 meters per second—over 1,000 miles per hour—and air there would continue moving at this speed for several minutes if the ground stopped rotating. These conditions would cause tsunamis, global storms, and fling debris fast enough to destroy nearly all human-made structures.

Io, Jupiter’s moon, is the most volcanically active body in the solar system

The innermost and third-largest of Jupiter’s four Galilean moons, Io’s volcanic activity is driven by tidal heating from Jupiter’s gravitational pull. Its atmosphere is very thin and primarily composed of sulfur dioxide, and its volcanic eruptions can exceed 1,000°C.

What happens if you throw trash into lava?

Each year, the world generates more than 2 billion tons of waste. Some have wondered: Could we dispose of it in lava? This video explores the science behind that idea, from lava lake temperatures to steam explosions and toxic emissions, and why the risks outweigh the benefits.

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.

Large igneous provinces are regions of massive ancient volcanic activity

Linked to some mass extinction events on Earth, LIPs contain significant amounts of igneous rock formed by the release of lava and gases over millions of years. India's Deccan Traps and the Siberian Traps are prominent examples of LIPs, whose climate-related impacts can serve as models for analyzing modern climate change.

Learn about the sun's corona, which is nonlethal despite a temperature of millions of degrees

The outermost layer of the sun's atmosphere is best seen during a solar eclipse, when the moon blocks the much brighter (and significantly cooler) solar surface. Despite the high-energy particles in the corona moving fast enough to escape the sun's gravity and gradually become solar wind, their density is too low to contribute meaningfully to the region's overall radiation.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

During glacier surging, these bodies of ice can move over half a football field a day

The movement of these glaciers, which repeatedly speed up and advance for months or years after stalling or moving backward for a time, results from melting ice that reduces friction between them and the ground, allowing them to slide more quickly. Scientists note that this effect is becoming more frequent due to climate change.

Heat is the leading cause of death in natural disasters

Floods are a distant second, followed by hurricanes. That's according to data reported by the National Oceanic and Atmospheric Administration.

Dive into the ocean's hottest water to explore hydrothermal vents

What can live at temperatures of 700 degrees Fahrenheit under skull crushing pressure with zero sunlight? Meet the animals living in the most extreme conditions on Earth in this four-minute video.

Ebola has an average fatality rate above 50%

The Ebola virus is one of the planet’s most feared bugs. Symptoms begin with fever and fatigue but quickly develop into severe vomiting, diarrhea, and internal and external bleeding. But why is it so deadly? In short, Ebola hijacks the immune system to rapidly make replicas of itself.

An interactive trek up Mount Everest

At just over 29,000 feet, Mount Everest is the highest summit on Earth and the premiere destination for serious climbers. The imposing peak has also claimed at least 322 lives over the past century, or between four and five victims per year. This...

Fun family fireworks turn ballistic

The American Pyrotechnics Association estimates that over 10,000 injuries result each year from fireworks, close to three-quarters of which occur around the Fourth of July. This video shows just one rather explosive miscue.

What is a sneeze? (And can it kill you?)

A sneeze is an important involuntary reflex to expel something that is irritating your nose. But can it kill you? No, say these silly video hosts. Although, the sneeze can expel air, saliva, and mucus at nearly 100 miles per hour in a five-foot radius. See them break it down with this quick, quirky video.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

View the ten deadliest tornadoes in US history.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Watch what the Ebola virus does inside our cells and organs in order to spread and survive.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Animal phobias are likely the most common type of phobias, followed by an extreme fear of heights.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.