Tsunami : After Earthquake Struck Russia
A powerful 8.8-magnitude earthquake struck Russia’s Kamchatka Peninsula recently, triggering tsunami warnings across the northern Pacific, including Alaska, Hawaii, and down to New Zealand.
- A tsunami is a series of waves generated by a large and sudden displacement of the ocean.
- Tsunamis can have devastating and wide-ranging effects, especially in coastal regions.
- The word tsunami is composed of the Japanese words “tsu” (which means harbor) and “nami” (which means “wave”).
- Large earthquakes below or near the ocean floor are the most common cause (about 80% of all known tsunamis are triggered by earthquakes), but landslides, volcanic activity, certain types of weather, and meteorites can also cause tsunamis.
- Not all earthquakes cause tsunamis; they must be strong and shallow (at least 6.5 magnitude and less than 70 km from the Earth’s surface), and move the seafloor vertically.
- Tsunamis radiate outward in all directions from their source and can move across entire ocean basins, around islands, and into bays, sounds, and up rivers.
- Out in the depths of the ocean, tsunami waves do not dramatically increase in height.
- But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases.
- The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave.
- Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters.
- Tsunamis can have heights of up to 30 m (98 ft) and reach speeds of 950 km per hour.
