What is a tsunami? These graphics explain their destructive power
Much of Coastal California was under a tsunami advisory and a small section remained under a tsunami warning early on July 30, USA TODAY reported.
Here is how tsunamis are created and why they're so dangerous:
What is a tsunami?
Unable to view our graphics? Click here to see them.
Tsunamis are a series of giant waves caused by undersea earthquakes at tectonic plate boundaries, or volcanic eruptions. Both displace massive amounts of water, which generate ocean waves that fan out from the quake's epicenter or the volcano's vent.
In a process known as shoaling, tsunami waves change dramatically in height and speed as they travel inland. Force from the seabed slows down waves as they reach shallow water. "The shallower the water, the slower the wave," according to sciencelearn.org.
In deep water, newly generated waves can travel at speeds of 500 mph or more, according to the National Oceanic and Atmospheric Administration. "The deeper the water, the faster they move," NOAA says.
While the waves are moving fast, they're not very high, usually about 3 feet.
The waves change as they enter shallow water near land, NOAA says:
?The distance between waves, known as wavelengths, gets shorter.
?The waves drop in speed to 20 to 30 mph.
?Height of the waves increases, usually to about 10 feet, though waves as high as 100 feet have been recorded.
Damage caused by tsunamis depends on where they make landfall. Tsunamis can travel significant distances inland, depending on topography and the strength of the waves.
"Reefs, bays, entrances to rivers, undersea features, and the slope of the beach can all influence the size, appearance, and impact of tsunamis when they strike the coast," NOAA says.
Tsunamis can also be caused by landslides, above or below the ocean surface, or by meteorites.
How did Russian earthquake compare to others?
Why do we call them tsunamis?
Tsunami comes from the Japanese words "tsu" for harbor, and "nami" for wave. Though the term "tidal wave" was once used to describe tsunamis, they are different from tidal waves, which are caused by ocean tides.
Worst tsunamis in history
The deadliest tsunami in history, caused by a 9.1 magnitude earthquake, struck the Indonesian island of Sumatra in the Indian Ocean on Dec. 26, 2004.
About 230,000 people were killed and 1.7 million others were displaced. Economic losses were estimated at about $17 billion.
The costliest tsunami in history took place off the east coast of Japan on March 11, 2011. A 9.1 magnitude earthquake, the largest ever recorded in Japan, caused about 18,000 deaths and about $318 billion in damages.
Shifting tectonic plates
How are tsunamis different from regular waves?
Regular waves are caused by wind. Strong, long-lasting winds create larger waves, with heights varying from 3 to 11 feet. Compared to tsunamis, they move relatively slowly, and their wavelengths are short, measured in feet. They reach the shore every few seconds.
Tsunamis are created by undersea disruptions and travel much faster than regular waves. Their wavelengths can be measured in miles, and they reach the shore minutes or hours apart. Their wave heights can range from 10 feet or more, reaching 100 feet in extreme cases.
Can you surf in a tsunami?
The short answer is no. Tsunami waves are different than regular waves used by surfers, says the University of Hawaii:
?Tsunami waves do not have faces - the concave sections of waves - so there's nothing for a surfboard to grip.
?Tsunami waves are filled with dredged-up trash.
?A tsunami wave approaching land is more like a wall of whitewater.
CONTRIBUTING Dinah Voyles Pulver, Thao Nguyen, Will Carless, Kathleen Wong, John Bacon, Joel Shannon, Jeanine Santucci
SOURCE USA TODAY Network reporting and research; Reuters; National Oceanic and Atmospheric Administration; sciencelearn.org; National Geographic
(This story was updated to include video.)
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Glasgow Times
4 hours ago
- Glasgow Times
SpaceX delivers new crew to orbiting station in just 15 hours
The four US, Russian and Japanese astronauts pulled up in their SpaceX capsule after launching from Nasa's Kennedy Space Centre. They will spend at least six months at the orbiting lab, swapping places with colleagues who have been up there since March. SpaceX will bring those four back as early as Wednesday. Moving in are Nasa's Zena Cardman and Mike Fincke, Japan's Kimiya Yui and Russia's Oleg Platonov – each of whom had been originally assigned to other missions. The docked SpaceX capsule next to the International Space Station (Nasa and SpaceX via AP) 'Hello, space station,' Mr Fincke radioed as soon as the capsule docked high above the South Pacific. Ms Cardman and another astronaut were pulled from a SpaceX flight last year to make room for Nasa's two stuck astronauts, Boeing Starliner test pilots Butch Wilmore and Suni Williams, whose space station stay went from one week to more than nine months. Mr Fincke and Mr Yui had been training for the next Starliner mission. But with Starliner grounded by thruster and other problems until 2026, the two switched to SpaceX. Mr Platonov was bumped from the Soyuz launch line-up a couple of years ago because of an undisclosed illness. Their arrival temporarily puts the space station population at 11. The astronauts greeting them had cold drinks and hot food waiting for them. While their taxi flight was speedy by US standards, the Russians hold the record for the fastest trip to the space station – a lightning-fast three hours.
Leader Live
4 hours ago
- Leader Live
SpaceX delivers new crew to orbiting station in just 15 hours
The four US, Russian and Japanese astronauts pulled up in their SpaceX capsule after launching from Nasa's Kennedy Space Centre. They will spend at least six months at the orbiting lab, swapping places with colleagues who have been up there since March. SpaceX will bring those four back as early as Wednesday. Moving in are Nasa's Zena Cardman and Mike Fincke, Japan's Kimiya Yui and Russia's Oleg Platonov – each of whom had been originally assigned to other missions. 'Hello, space station,' Mr Fincke radioed as soon as the capsule docked high above the South Pacific. Ms Cardman and another astronaut were pulled from a SpaceX flight last year to make room for Nasa's two stuck astronauts, Boeing Starliner test pilots Butch Wilmore and Suni Williams, whose space station stay went from one week to more than nine months. Mr Fincke and Mr Yui had been training for the next Starliner mission. But with Starliner grounded by thruster and other problems until 2026, the two switched to SpaceX. Mr Platonov was bumped from the Soyuz launch line-up a couple of years ago because of an undisclosed illness. Their arrival temporarily puts the space station population at 11. The astronauts greeting them had cold drinks and hot food waiting for them. While their taxi flight was speedy by US standards, the Russians hold the record for the fastest trip to the space station – a lightning-fast three hours.
Powys County Times
6 hours ago
- Powys County Times
SpaceX delivers new crew to orbiting station in just 15 hours
SpaceX delivered a fresh crew to the International Space Station on Saturday, making the trip in a quick 15 hours. The four US, Russian and Japanese astronauts pulled up in their SpaceX capsule after launching from Nasa's Kennedy Space Centre. They will spend at least six months at the orbiting lab, swapping places with colleagues who have been up there since March. SpaceX will bring those four back as early as Wednesday. Moving in are Nasa's Zena Cardman and Mike Fincke, Japan's Kimiya Yui and Russia's Oleg Platonov – each of whom had been originally assigned to other missions. 'Hello, space station,' Mr Fincke radioed as soon as the capsule docked high above the South Pacific. Ms Cardman and another astronaut were pulled from a SpaceX flight last year to make room for Nasa's two stuck astronauts, Boeing Starliner test pilots Butch Wilmore and Suni Williams, whose space station stay went from one week to more than nine months. Mr Fincke and Mr Yui had been training for the next Starliner mission. But with Starliner grounded by thruster and other problems until 2026, the two switched to SpaceX. Mr Platonov was bumped from the Soyuz launch line-up a couple of years ago because of an undisclosed illness. Their arrival temporarily puts the space station population at 11. The astronauts greeting them had cold drinks and hot food waiting for them. While their taxi flight was speedy by US standards, the Russians hold the record for the fastest trip to the space station – a lightning-fast three hours.
