Tsunamis are among the most destructive forces in nature. With little warning, these giant waves can reach heights ranging from 10 feet (3.05 m) to, in extreme cases, 100 feet (30.5 m).
Most tsunamis are caused by undersea earthquakes that occur at the boundaries between tectonic places. When these geologically active areas experience a sudden movement in the ocean floor, the displaced water results in a series of gigantic rolling waves that radiate out from the source. Less frequently, tsunamis are caused by the eruption of undersea volcanoes, underwater landslides, or even large meteorites hitting the ocean.
In the deepest parts of the sea, tsunamis are capable of reaching speeds of around 500 miles per hour (805 km/h) – comparable to the speed of a jet airplane – allowing them to cross vast expanses of ocean in a matter of hours. Remarkably, tsunamis lose very little energy as they travel. Large tsunamis, like the 2004 Indian Ocean tsunami, can travel thousands of miles and cause damage to far-flung countries.
Unlike wind-driven waves that only affect the ocean’s top layer, tsunami waves travel through the entire water column. Interestingly, you might not even notice a tsunami if you were onboard a boat in the middle of the ocean – the top of the wave might only cause a few feet of displacement beyond the water surface. But when tsunamis approach the shallow water close to a shoreline, they finally slow down, their wavelength decreases, and they increase dramatically in height.
The awful, awe-inspiring power of tsunamis:
- Although tsunamis usually appear with little warning, the vacuum effect caused by the arrival of the tsunami’s trough before the wave crest typically gives at least a few minutes of notice, alerting people to get to high ground as soon as possible.
- Around 80% of all tsunamis occur in the “Ring of Fire” region of the Pacific Ocean, due to the frequent tectonic activity that causes earthquakes and volcanoes. Twenty-six nations in the Pacific region participate in the Pacific Tsunami Warning System, which monitors seismic activity and water levels in the hopes of alerting coastal residents as quickly as possible in the event of a tsunami.
- It’s easy to underestimate the power of fast-moving water, which is why floods are so dangerous. Even six inches of water could knock you off your feet, while a foot of water could carry away a car. Now imagine a tsunami wave with a height of 10 feet or more.