Tsunamis can last for days as their successive waves hit a coastal area, with early warning systems indicating the likelihood of a tsunami's arrival on a scale from watch to advisory to warning.

A tsunami—Japanese for 'harbor wave'—can begin with a drop in sea level before rising, which has contributed to its mistaken categorization as a tidal wave, despite being unrelated to the moon's gravity.

Tsunamis are a series of waves rather than a single one, and boats are safer from them in deeper waters, where tsunami waves are smaller.

View a tsunami travel time map to learn how many hours its waves are estimated to take to reach different parts of Earth when originating from a list of geologically active locations.

Although earthquakes cause about 80% of tsunamis, almost all earthquakes lack sufficient energy to cause the sudden shift in the ocean floor needed to substantially displace enormous volumes of water.

Rather than being triggered by a massive displacement of water from a geological event, meteotsunamis are caused by rapid changes in air pressure from fast-moving weather systems.

Because seismic waves travel 100 times faster than tsunami waves—waves typically travel faster through solids than liquids—measurements of geological activity help tsunami detection systems provide early warnings.

The National Weather Service communicates tornado risks on a three-tier system

During a tornado watch, atmospheric conditions favor the development of a tornado, and residents in an area should be prepared to seek refuge. A tornado warning is issued if a tornado has been detected, while a tornado emergency indicates a violent tornado has touched down in the area, with severe threats to human life and property expected.

NASA's GUARDIAN software uses changes in satellite navigation signals and AI-powered detection algorithms to anticipate tsunamis and provide real-time alerts to at-risk communities before the phenomena are detected by tidal sensors.

Wave tanks can be used to create and study the impacts of tsunamis by building tension in an underwater object before allowing it to slip and rapidly displace water.

Explore an interactive time-lapse of reported tsunami events since 1850, with identified cause, recorded observations, known deaths, and other information available for each.

The tallest tsunami in recorded history was 524 meters (1,720 feet) high—taller than the Empire State Building—and occurred in Lituya Bay, Alaska, in 1958 after an earthquake dislodged a rockface into the water.

Infrastructure built to limit tsunami damage includes channels to divert water, floodgates, and seawalls, such as the approximately 400-kilometer (249-mile) wall built in Japan after the 2011 Tōhoku earthquake and tsunami.

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.

Explore tips from the American Red Cross on preparing for a tornado

If you live in a region prone to tornadoes, have a plan to retreat to a safe room built to withstand strong winds, such as an underground shelter or a windowless room at the lowest level of a study building, in case of a tornado warning. Having a stay-at-home kit with non-perishable food and water, medications, batteries and chargers, and a battery-powered radio is also essential.

From 1610 BCE to 2025 CE, at least 250 of the over 3,000 confirmed tsunamis were deadly, and the 2004 Indonesia tsunami was the deadliest, with over 227,000 casualties.

Quicksand—a mixture of sand with clay or silt soaked in water that gives way when enough pressure is applied—is denser than the human body, meaning you naturally float inside it.

After a landslide, repeat activity may follow the appearance of cracks, springs of water, or dirt, sand, and rocks tumbling down from scars—exposed portions of Earth where the initial landslide began.

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.

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.

Explore how global teams coordinated by the UN's International Search and Rescue Advisory Group find and rescue survivors of large-scale earthquakes, from preliminary surveys to recovering bodies.

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.

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.

In the US, flash floods—rapid floods that occur within six hours of rain—kill more people than tornadoes, hurricanes, and lightning.

Tornado myths include suggestions to hide beneath a bridge or to open windows

Winds can accelerate due to a tunneling effect as they pass under a structure, making seeking shelter from a tornado in a mobile home or recreational vehicle highly discouraged. Significant tornado damage results from debris being picked up and hurled by strong winds, making it unsafe to be near windows that may shatter.

Explore the decommissioning work at the Fukushima Daiichi Nuclear Power Station

This virtual tour explores the nuclear disaster site, which resulted from a magnitude 9.1 earthquake and tsunami on March 11, 2011, and the various processes underway to remove debris, fuel, and contaminated water.

Fast-changing conditions during their formation make tornado forecasting difficult

The final steps of tornadogenesis—the process of forming a tornado—depend on near-surface details, such as local geography, which are difficult for radar to observe and affect how funnel clouds make contact with the ground. Inconsistencies in storm behavior have limited the amount of advance warning people receive before tornadoes touch down.

Learn all about different types of extreme weather

Find out in more detail about different types of extreme weather, from flooding to thunderstorms, from tropical cyclones to sandstorms, and more (w/ helpful videos).

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.

If, not when: An earthquake is destined to destroy the Pacific Northwest.

When the Cascadia fault line ruptures, it could be North America’s worst natural disaster in recorded history. Read a deep dive into the history of the region and the potential impact of the eventual seismic boom.

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.

Track active wildfires, floods, and other natural disasters across the US in real time with this interactive map.

The risk of tornadoes and storm surges is greatest on the 'dirty side' of a hurricane

Winds in the right-front quadrant of the storm are amplified by the hurricane's motion and its rotation, which both move air in the same direction. Upon making landfall, these winds pull water from the Gulf and Atlantic onto land, creating storm surges. Tornadoes can also be generated from large differences in wind speed and direction at various heights.

Hurricane Helene dumped enough water to fill Lake Tahoe

Alongside a rainstorm that moved into the region ahead of it, the hurricane released an unprecedented 40 trillion gallons of rain on the southeastern US, causing catastrophic flooding and at least 100 deaths. Meteorologists suggest climate change is exacerbating the severity of such events.

Study pinpoints where to hide during a nuclear blast

There’s no surviving the fireball of a nuclear bomb, but beyond that, there are certain spots indoors where you can try avoid the destructive shockwave.

'FAST': An acronym to remember stroke symptoms to look for

The primary factor in surviving a stroke is how quickly one gets the appropriate medical treatment. “FAST” refers to the four most noticeable symptoms of a stroke: face-dropping ("F"), arm weakness ("A"), speech difficulty ("S"), and "time to call 911" ("T").

As of 2026, the world's largest tropical cyclone was Typhoon Tip, whose size spanned the equivalent of half the continental US.

Tropical cyclones, which include hurricanes and typhoons, consist of three main parts: the eye, the eyewall, and rainbands.

Explore and visualize AI-driven riverine and flash-flood forecasts across more than 150 countries to anticipate these natural disasters up to seven days in advance.

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.

Plastic debris across the ocean aids the spread of invasive species

The durable, long-lasting material can serve as a platform for living organisms to latch onto and ride over vast distances. After the 2011 earthquake and tsunami in Japan, a large dock carrying 100 tons of living organisms native to Japan washed up on Oregon's coastline, confirming the ecological threat.

NOAA's interactive sea level rise viewer

How will rising seas affect you? Launch NOAA's sea level rise viewer and zoom in on impacts to different parts of the United States, or type in your city or address to learn more.

Chernobyl pushed the world to create rapid-alert systems for nuclear accidents

In the aftermath of the disaster, nations adopted new agreements requiring immediate international notification of nuclear accidents. They coordinated emergency assistance—efforts led by the International Atomic Energy Agency to prevent future disasters from being concealed when radiation emergencies occur.

Rapid intensification is the increase in a hurricane's sustained wind speed by at least 35 miles per hour within 24 hours, which can strengthen it by up to two categories.

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

Turtles' sense of direction comes from sensitivity to Earth's magnetic field and wave movement

Female sea turtles use this ability to migrate hundreds of kilometers across the ocean from their feeding grounds to the beaches where they were born to lay their eggs. Researchers have found that these turtles can reach these beaches despite ending up significantly off course as they detour away from predators or toward foraging territories.

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.

Hurricanes are classified according to their maximum sustained wind speed

The Saffir-Simpson Hurricane Wind Scale is a rating system that organizes hurricanes into one of five categories. Categories three and higher are classified as major hurricanes, but all categories can produce deadly storm surges and rain-induced floods.

A list of common questions and answers about hurricanes from NOAA

This FAQ answers many questions hurricane researchers at NOAA have received, sorted by category. The answers provide insights into hurricane classification and naming, forecasting their movement and growth, and tips for preparing ahead of landfall.

Various types of tornadoes are distinguished by their shape, size, and location

Waterspouts form over water as long, thin columns of mist and air, while elephant trunks are tornadoes that elongate vertically as they become tilted during their formation, resembling the mammal's appendage. Wedge tornadoes are among the most powerful, often spanning a mile or more in width.

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.