All Types of Tsunamis

••• Camaro99z/iStock/GettyImages

A tsunami is a catastrophic sea wave that achieves landfall and causes destruction. Its source is a major geographic event under sea level, such as an earthquake, volcano eruption, or landslide. Though frequently called tidal waves, tsunamis have nothing to do with ocean tides. Many Pacific and Indian Ocean coastal countries maintain tsunami warning systems so local governments can establish timely evacuation routes. The warning systems specify what kind of tsunami may be moving toward land and provide evacuation information.

Local Tsunami

A local tsunami is a tsunami that causes damage in relatively close proximity to the tsunami-causing event. Specifically, the underwater event -- usually an earthquake -- that produces a local tsunami happens within 100 km, which is a little over 60 miles, of the land damage that results. These tsunamis can be devastating because the time between the underwater event and the arrival of the tsunami can be under an hour -- and sometimes less than 10 minutes. This does not provide sufficient time for comprehensive evacuations.

Regional Tsunami

A regional tsunami is one that causes damage from 100 km to 1,000 km from the underwater event that causes the tsunami. In some cases, more contained damages occur outside the 1,000 km perimeter. Regional tsunamis provide slightly more warning time than local tsunamis, making landfall between one and three hours of the event that causes them. Within the 1,000 km area, just one to three hours may not provide enough time for people to evacuate safely.

Distant Tsunami

A distant tsunami, also called a tele-tsunami or ocean-wide tsunami -- originates with an exceptionally powerful and destructive event more than 1,000 km away from landfall. Though a distant tsunami may first appear like a local tsunami, it travels across wide swathes of ocean basin. There is more time to evacuate and escape a distant tsunami, but it also covers a larger mass of land and tends to cause extensive and widespread destruction.

The Distant Tsunami of 2004

The most devastating tsunami on historical record occurred in the Indian Ocean on December 26, 2004. On that day, a massive underwater earthquake -- measuring at 9.1 out of 10 on the Richter scale -- occurred off the northern coast of Sumatra, Indonesia. The resulting distant tsunami hit the coasts of Indonesia, Thailand, Malaysia, India, Sri Lanka, Myanmar, the Maldives, and even countries in East Africa. At least a quarter of a million people died, with the worst damage concentrated in India, Indonesia, Sri Lanka,Thailand and the Maldives.

Related Articles

Mini Earthquakes Rock SoCal Every Three Minutes, Science...
How Is a Tsunami Created?
Ancient Fault Lines in Pennsylvania
How Do Tsunamis Stop?
When Is Hurricane Season in Hawaii?
How to Calculate Epicenter
What Seasons Do Floods Occur?
Facts About Mount Etna
How Do Tsunamis Affect Human Lives?
Tornadoes' Effects on People
The History of Solar Flares on Earth
How Do Earthquakes Affect People & Land?
Chances of a Solar Eclipse
How Does an Earthquake Form a Tsunami?
This Mysterious Seismic Event Could Have Birthed a...
A Fault Line in California is Creeping - Is The Big...
Scales Used to Measure Earthquakes
What Is the Difference Between Magnitude and Intensity?
What Kind of Damage Has Mauna Loa Caused?
The Causes of Floods