A tsunami is also called a harbor wave. A tsunami is usually caused by a major disturbance like an earthquake, underwater explosions or volcanic eruptions. A tsunami is quite similar to a rapidly rising tide. They have a very long wave length and they rise in height when they reach shallow waters. Some tsunamis are caused by landslides. They are a smashing force of water that travels at a very high speed and they can cause major destruction. Tsunamis in the Atlantic Ocean have caused death and destruction. In 2004, a tsunami struck Sri Lanka and Indonesia. Tsunamis that occur in the Atlantic Ocean stike the east coast of the United States. The worst recorded tsunami was the one that struck Indonesia in 2004.
Most of the tsunamis occur in the Pacific Ocean. The east coast of the United States is a passive range for Tsunami activity. The Atlantic Ocean has fewer tsunamis than the Pacific Ocean because it has less volcanic activity. The majority of the tsunamis that occur in the Atlantic Ocean are often caused by earthquakes or volcanoes. These tsunamis that have occured in the Atlantic Ocean have caused localized damages and deaths. A large historic tsunami that occured in the Atlantic was recorded in 1755 and this one struck Portugal. In 1867, there was another tsunami that hit the U.S. Virgin Islands. A tsunami hit really close to the state of Maine in 1929. It hit Grand Banks, Newfoundland, Canada and reached heights of 27 m.
In Maine, only small tsunami events have been recorded in the years of 1872 and 1926. Threats do exist on the east coast of the United States and they are often caused by landslides off the coasts of Virginia and North Carolina. The tsunamis here are quite similar to a category 3 or 4 hurricane. There are tsunami warning systems that warn people when a tsunami is about to take place. In the state of Hawaii, there is an International Tsunami Information Center that keeps watch and provides alerts and warnings. Ther is no monitoring program in the Atlantic Ocean, but someday soon there will be. They really need these monitoring systems wherever the tsunamis can occur so that people can be warned of the danger. What protects Maine from an Atlantic Ocean Tsunami is the shallow Georges Bank offshore. Water levels often fall really low before a tsunami will strike.