Rare Video: Japan Tsunami | National Geographic

Summary

On March 11, 2011, northern Japan was devastated by a magnitude 9.0 earthquake and massive tsunami. The quake, one of the largest ever recorded, triggered tsunami waves that overran coastal cities, flooding up to three miles inland and overwhelming even the largest seawalls. The disaster claimed over 28,000 lives, but cutting-edge technology, including GPS and high-resolution video footage, provided invaluable data for studying the event. These insights help better understand the forces of nature and improve future disaster preparedness to save lives.

Takeaways

• 😀 A magnitude 9.0 earthquake struck northern Japan on March 11, 2011, causing widespread devastation.
• 😀 The earthquake, centered 80 miles offshore, triggered tsunami warnings immediately for coastal cities.
• 😀 People in coastal areas knew to seek higher ground as the tsunami waves inundated cities, causing massive destruction.
• 😀 Incredible footage from Kesennuma shows people watching in horror as tsunami waves demolished buildings and mixed with debris.
• 😀 Tsunami waves, which reached over 18 feet in height, breached seawalls in cities, overwhelming Japan’s defenses.
• 😀 Despite being the largest earthquake ever recorded in Japan and one of the five largest globally, the March 11 disaster caused significant loss of life, with over 28,000 people confirmed dead or missing.
• 😀 The earthquake occurred when two tectonic plates collided under the ocean, displacing massive amounts of water and generating enormous waves.
• 😀 In deep water, tsunami waves travel fast, reaching speeds up to 500 miles per hour, but only a few feet high, barely noticeable to ships.
• 😀 As tsunami waves enter shallow waters, their speed decreases, but their height increases dramatically, causing massive damage.
• 😀 Advanced technology, including high-precision GPS stations, allowed geophysicists to study the quake and tsunami in great detail, creating valuable visualizations for future research and disaster preparedness.
• 😀 Some tsunami waves reached as far as 3 miles inland, demonstrating the immense power and reach of the event, with new evidence available to help mitigate future risks.

Q & A

What event does the transcript describe, and when did it occur?

The transcript describes the magnitude 9.0 earthquake and subsequent tsunami that struck northern Japan on March 11, 2011.

Where was the epicenter of the earthquake located?

The earthquake's epicenter was located about 80 miles offshore from northern Japan.

What did people do in response to tsunami warnings?

People in coastal cities immediately ran to higher ground to escape the tsunami after the warnings went up.

What was captured in the footage from Kesennuma?

The footage from Kesennuma captured people retreating to a high-rise rooftop and watching in horror as tsunami waves inundated their city, knocking buildings into rubble.

What was the height of the seawall that failed in the city of Komatsu?

The seawall in Komatsu was 18 feet high, but it was not enough to withstand the magnitude of the March 11 disaster.

Why did the tsunami waves grow in height as they approached the shoreline?

As tsunami waves entered shallow waters, friction with the ocean floor slowed the waves down but caused their height to increase dramatically.

What unusual perspective was captured during the March 11 tsunami?

A rare aerial view was captured showing a tsunami wave approaching the Japanese shoreline.

How far did some of the tsunami waves travel inland?

Some tsunami waves reached as far as 3 miles inland, causing massive destruction.

What technology was used to study the March 11 earthquake and tsunami?

More than 1,200 high-precision GPS stations in Japan were used to study the earthquake, and data from these stations were used to create a detailed visualization of the event.

How fast did the waves of displacement from the earthquake move?

The waves of displacement from the earthquake moved as fast as 5 miles per second.