Early warning systems indicate the likelihood of a tsunami on a scale from watch to advisory to warning, and those in coastal areas may anticipate its arrival by feeling a long earthquake.

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.

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.

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 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.

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.

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.

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.

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

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.

The world's tallest tsunami 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 nearly 400-kilometer (249-mile) wall built in Japan after the 2011 Tōhoku earthquake and tsunami.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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

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.