Every coastal area and river estaury potentially threatened by tsunamis, but they are most likely to happen on shores facing directly a megathrust. Scientists estimate that tsunami is commonly occurring in Indonesia and pacific ocean(Japan), because the pacific rim bordering the ocean has a large number of earthquake zone. However, the tsunami have also occurred at caribbean ocean and Medittarian sea as well.
Facts about tsunami: 1. 6.9-magnitude earthquake struck off Japan's Honshu island on Tuesday, triggering tsunami waves and bringing back traumatic memories for locals of the devastating 2011 Fukushima disaster.
2. On the night of July 9, 1958, an earthquake along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet. The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. The wave hit with such power that it swept completely over the spur of land that separates Gilbert Inlet from the main body of Lituya Bay. The wave then continued down the entire length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska. The force of the wave removed all trees and vegetation from elevations as high as 1720 feet (524 meters) above sea level. Millions of trees were uprooted and swept away by the wave. This is the highest wave that has ever been known.
TSUNAMI SAFETY RULES: 1. All earthquakes do not cause tsunamis, but many do. When you know that an earthquake has occurred, stand by for a tsunami emergency message. 2. An earthquake in your area is one of nature's tsunami warning signals. Do not stay in low-lying coastal areas after a strong earthquake has been felt. 3. Tsunamis are sometimes preceded by a noticeable fall in sea level as the ocean retreats seaward exposing the seafloor. A roar like an oncoming train may sometimes be heard as the tsunami wave rushes toward the shore. These are also nature's tsunami warning signals.