Tsunamis are caused by earthquakes of magnitude 7.0 with hypocenters within 100 kilometers of the seafloor, large sections of which can be significantly shifted to displace water suddenly.

Deep-sea trenches form when one tectonic plate subducts another underwater

Oceanic plates sink when colliding with less dense continental plates, bending the seafloor into steep depressions that can be almost 11 kilometers deep. Many of Earth’s strongest earthquakes occur at these plate boundaries, often featuring volcanic activity.

Tectonic earthquakes are caused by tectonic plates sliding past one another at fault zones, deforming rock through friction as energy builds like a stretched rubber band.

Earthquakes of identical magnitudes are unlikely to cause equal damage because magnitude only measures energy released, and earthquake severity depends on environmental factors, such as local architecture and geological conditions.

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.

When oceanic plates sink beneath tectonic ones, they can generate magma

At converging oceanic-continental plate boundaries, the subduction of the oceanic plate introduces seawater that reduces the melting temperature of the overlying mantle. This causes it to melt into less dense magma, which can rise to fuel more volcanic activity.

View a map of the world's major earthquakes from 1956 to 2022, which can be used to identify tectonic plate boundaries.

Scientists determine earthquake locations by comparing how long it takes different seismic waves to be detected at three stations around the world, from which an origin, or hypocenter, can be triangulated.

Visualize the power and frequency of earthquake magnitudes.

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

Some earthquakes can produce smaller tremors called boomerang earthquakes, which travel in the opposite direction and ripple back to the original earthquake's source.

Research suggests a 95-kilometer-wide (59-mile-wide) asteroid impact could boil the Earth's oceans

Even a 1-kilometer-wide (0.62-mile-wide) asteroid can trigger earthquakes and tsunamis on impact with oceans. The overwhelming majority of asteroids that reach Earth are much smaller and burn up in the atmosphere before reaching the ground.

How the Turkish earthquake created a 100-mile rupture

A February 2023 earthquake devastated parts of Turkey and Syria destroying entire blocks, with more than 50,000 people killed. A scientific analysis revealed a fault line with a 100-mile-long rupture, where separate tectonic plates moved more than...

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

Rather than predicting them in advance, earthquake early warning systems detect tremors moments after they begin and send notifications that reach users before the seismic activity does.

38 thought-provoking facts about the ocean

Coral produces its own sunscreen, tsunamis move at 500 miles per hour, one of the loudest sounds ever recorded came from an ice quake, and other interesting facts collected from sources such as National Geographic and NASA.

The San Andreas Fault is an example of tectonic plates sliding past each other

The transform boundary divides the opposing movements of the Pacific and North American tectonic plates, which create shear zones that distort and fracture rock. These movements produce shallow earthquakes as rocks are gradually displaced hundreds of miles.

Just as light bends at different angles as it travels through different materials, seismic waves move in different directions through Earth's interior, revealing the presence of layers with varying properties.

Some tectonic plates move faster than their underlying convection currents

Like a chain slipping off a ledge, as tectonic plates sink, their weight can pull the rest of the trailing plate forward, accelerating their movement. Plates can also break apart and fall, creating a suction effect that drives movement, resembling leaves following a passing car.

A magnitude 25 earthquake would release enough energy to destroy the sun, while a particle of dust drifting onto a table would have a magnitude of about -15.

Storm surges, not winds, are the leading cause of hurricane-related fatalities

A storm surge is an abnormal rise in water levels generated by a storm that exceeds predicted tides. It is particularly dangerous in coastal regions, where it can generate extreme flooding well before the hurricane makes landfall.

Reported earthquake magnitudes often change because initial values are based on limited information, whereas revised magnitudes account for factors such as fault size, rupture duration, and seismic wave behavior.

Scientists investigate Earth's interior by studying seismic waves

Scientists investigate Earth's interior by studying seismic wavesBelow Earth's atmosphere lies the crust, which extends to the Mohorovičić discontinuity between five and 20 miles below Earth's surface. Below the crust lies the mantle, the liquid-metal outer core, and the solid inner core, which surpasses 5,200 degrees Celsius (9,392 degrees Fahrenheit).

Earth is constantly bombarded by material from space

Most of this matter is composed of small particles, with any smaller than 33 feet in diameter burning up in the atmosphere. Larger asteroids can reach the ground, and those larger than several thousand feet cause global damage, including earthquakes and tsunamis.

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.

Enhanced geothermal power systems can trigger earthquakes by injecting fluid into rock, increasing subterranean pressure.

Convection flows in Earth’s mantle drive the movement of tectonic plates

These processes transfer heat from Earth’s core to the surface via rising magma plumes, while cooler, denser rock falls into the mantle at rates similar to human fingernail growth. These rates are determined by combining seismic data with computer simulations to model Earth’s interior.

Why Turkey's earthquakes were so deadly

The death toll from February 2023 has reached the tens of thousands, making it one of the deadliest natural disasters of the century. The intense seismic activity combined with poor and unregulated construction in many areas to drive fatalities....

The biggest ocean waves in the world, which regularly reach between 80 and 100 feet, are primarily caused by a 140-mile-long submarine canyon that reaches a maximum depth of 16,000 feet.

Geological tremors on the moon provide evidence that it is shrinking

Apollo seismometers have collected moonquake data, which scientists have analyzed to map the moon's interior and reveal that fault slips producing tremors are the result of sublunar cooling and contraction. It also revealed that the moon's inner core is about 500 kilometers (311 miles) across.

Into the Mariana Trench

Located in the western Pacific Ocean, the Mariana Trench is the deepest known point on Earth. Its lowest point, known as Challenger Deep, is farther down than the height of Mount Everest by more than a mile. This 13-minute video discusses how the trench was formed, and the extreme conditions at the sea floor.

Hawaii formed from oceanic plate movement over a hot spot in the mantle

Abnormally hot magma rose through the crust and emerged from the seafloor, where it cooled and piled onto layers that became tall enough to form an island. As the plate moved, the existing island moved away and a new one formed over the hot spot, repeating for each Hawaiian island.

How do hurricanes form?

Tropical cyclones, also called hurricanes and typhoons, cause catastrophic damage when they strike land. This four-minute video explores the life cycle of cyclones—how atmospheric conditions, ocean temperatures, and the Earth's rotation combine to create them, and how they are driven by winds and eventually weaken after moving over land.

Tornadoes produce inaudible signals to humans hours before forming

Researchers at the National Oceanic and Atmospheric Administration have found that tornado-producing storms generate specific sounds below the range of human hearing, much like the infrasonic signals produced by earthquakes and avalanches. Although difficult to distinguish from wind noise, scientists hope to build systems that use these signals to improve tornado forecasting.

Records of Earth's magnetic field on the seafloor validated plate tectonics

Matching glacial, fossil, and rock records, mountain ranges, and continental shapes across oceans was insufficient evidence for continental drift. Precise measurements of magnetic minerals on the ocean floor revealed seafloor spreading, which could only be explained by moving landmasses.

What makes the world's biggest waves?

Some of the world’s biggest waves, routinely reaching 100 feet high, are formed near the town of Nazaré, Portugal. But what makes this area so prone to massive swells? While a number of factors are involved, the key feature is the Nazaré Canyon,...

Oceans absorb 90% of warming from greenhouse gases

Oceans are providing increasingly more energy to power hurricane intensity. Current projections show rapid intensification is becoming more common, increasing the likelihood of Category 4 and 5 storms.

Watch the destructive force of bottom trawling on marine ecosystems

Bottom trawling is a fishing method where a net is dragged along the seafloor to catch a species of interest. The process produces as much carbon dioxide yearly as global aviation and leaves trails of destruction large enough to be seen in space.

The way hurricanes are categorized may mislead the public to their dangers

The Saffir-Simpson scale categorizes hurricanes based on wind speed, but tropical cyclones' main dangers are storm surges and heavy rainfall. To better communicate risks to the public, a new system that incorporates hurricane size, water content, and other complexities should be developed.

Why do flash floods occur?

Flash flooding can be more dangerous than traditional floods, occurring within the span of hours and exhibiting rapid currents. Here's how atmospheric conditions and geography combine to make some locations ripe for the disaster.

Disposal wells for fracking wastewater have been linked to spikes in seismic activity

A study of all such underground wells in the central and eastern US found that they were 1.5 times more likely to be associated with earthquakes than oil recovery wells. The link between fluid injection and earthquakes was strongest at disposal wells where fluid was injected quickly.

Bomb cyclones can produce heavy rain, blizzard conditions, and intense winds

Known as "bombogenesis" in meteorology, these systems get their colloquial name from their rapid intensification over a 24-hour period—a phenomenon seen in some tropical cyclones. They occur most commonly along the coasts of the Northeast and Northwest US when there is a severe temperature difference between colliding air masses.

How big is a supernova explosion?

Supernovas are the biggest explosions in the universe, often obliterating the area surrounding them. So what would happen if one exploded near Earth? If the sun went supernova it'd be like getting hit by a nuclear explosion every second for weeks. Of course, that's not happening anytime soon. This animated video shows how distance is the key factor, and how you shouldn't be worried.

Small elevation differences drastically protect homes in hurricanes

The construction of seaside homes has long involved building residences on elevated stilts, but this feature adds costs—and some elevated homes still fail. Explore the engineering behind the ideal height of a hurricane-proof building.

Simulate geological activity at plate boundaries

You are given a planetary model with optional rock formation and your choice of the number of tectonic plates and their densities. Draw continents, assign forces and plate boundary types, and run the simulation across map types to observe earthquakes, volcanoes, and other geological activity.

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.

Data-packed infographic on Earth's oceans

Did you know more than 200 million people live on land that could be flooded by rising sea levels? Learn fascinating facts about the ocean from this data-filled infographic from the Woods Hole Oceanographic Institute.

What happens when a whale dies and falls to the ocean floor

A large whale's body can blanket more than 538 square feet of ocean floor. That's an enormous amount of organic matter, providing food for the ecosystem for centuries. Researchers have discovered bones on the seafloor from whale species that have been extinct for over 100,000 years.

Some scientists hypothesize that stressed rocks can discharge built-up static electricity in the form of lightning—a phenomenon known as fracto-luminescence, or earthquake lights.

Every day, lightning releases several Hiroshima bombs' worth of energy into the atmosphere

If all this lightning struck one location at once, the bolt would be the diameter of the center circle of a basketball court, turning the entire court into a crater. Its heat would ignite surfaces for miles around, and its shockwave would demolish buildings.

Deep sea fish rely on a molecular strengthener to prevent being crushed

Trimethylamine N-oxide (TMAO) stabilizes hydrogen bonds and prevents water and proteins within organisms from being misshapen under immense pressure. Compounds called piezolytes protect cellular membranes from being crushed in regions like the Mariana Trench, where pressures are 1,100 times greater than surface atmospheric pressure.