Since earthquakes cannot be predicted, we do not know when a tsunami will happen before the earthquake occurs. Once a large potentially tsunamigenic earthquake does occur, we can forecast tsunami arrival times and wave heights through the use of computer modeling. You can learn more on the NCTR website: http://nctr.pmel.noaa.gov/tsunami-forecast.html

Tsunamis are also triggered by landslides into or under the water surface, and can be generated by volcanic activity and meteorite impacts. See similar questions...

On the average, two tsunamis occur per year throughout the world which inflict damage near the source. See similar questions...

No. U.S. coastal communities are threatened by tsunamis that are generated by both local earthquakes and distant earthquakes. Local tsunamis give residents only a few minutes to seek safety. Tsunamis of distant origins give residents more time to evacuate threatened coastal areas but increase the need for timely and accurate assessment of the tsunami hazard to avoid costly false alarms. Thus, U.S. See similar questions...

Anything that rapidly displaces a large volume of water can cause a tsunami. Typically, tsunamis are caused by underwater earthquakes, but landslides, volcanic eruptions, calving icebergs, and (very rarely) meteorite impacts can also generate tsunamis. These types of events can cause large disturbances in the surface of the ocean, and when gravity pulls the water back down, the tsunami is born. See similar questions...

No. Neither the USGS nor any other scientists have ever predicted a major earthquake. They do not know how, and they do not expect to know how any time in the foreseeable future. However, based on scientific data, probabilities can be calculated for potential future earthquakes. For example, scientists estimate that over the next 30 years the probability of a major EQ occurring in the San Francisco Bay area is 67% and 60% in Southern California See similar questions...

Tsunami velocity depends on the depth of water through which it travels (velocity equals the square root of the product of the water depth times the acceleration of gravity). Tsunamis travel approximately 475 mph in 15,000 feet of water. In 100 feet of water the velocity drops to about 40 mph. A tsunami travels from the central Aleutian Is. to Hawaii in about 5 hours and to California in about 6 hours, or from the Portugal coast to North Carolina in about 8.5 hours. See similar questions...

Since a tsunami consists of a series of waves, the danger can last for many hours. Large tsunamis are generally recorded for a few days following the event. See similar questions...

No such event has ever occurred in living memory. Nonetheless, there is an early warning system. In any case, country properties on Santa Maria are never found less than 110 yards (100 metres) above sea level. See similar questions...

It is not possible to predict with certainty that training will be successful for a particular condition. But for the more common conditions we see, a reasonable prediction of outcome is usually possible. More important, however, the effectiveness of the training can usually be assessed early in the course of training. For most conditions, there are no known adverse side effects of the training, provided that it is conducted under professional guidance. See similar questions...

First the behaviour of the tide has to be recorded by a tide gauge at each particular location and the results subsequently analysed. The results of the analysis, known as tidal constants, are then used in a computer program to predict the behaviour of the tide for any period required. A more detailed explanation is available at TotalTide. Upon exiting the TotalTide demonstrator, clicking on 'About Tidal Prediction' will bring up pages about tides and tidal theory. See similar questions...

The idea that tornadoes may form as a result of warm moist air colliding with cold Canadian air and dry air from the Rockies is a gross oversimplification. Many thunderstorms form under those conditions, which never come close to producing tornadoes. Even when the large-scale environment is quite favorable for tornadoes, not every storm spawns one. See similar questions...

Yes. Tsunamis have been recorded in all the major oceans of the world. However, this phenomenon is mainly restricted to the Pacific basin, an area surrounded by volcanic island arcs, mountain chains and subduction zones earning the nickname the "ring of fire", as it is the most geologically active area on the planet. See similar questions...

Good sources of information about tsunamis are the Tsunami links from the NOAA/PMEL Tsunami page, the NOAA/PMEL National Tsunami Hazard Mitigation Program page, and the NWS FAQ page Graphics Credits: the Great Wave off the Coast of Kanagawa, by the Japanese artist Hokusai, from the University of Washington Tsunami Page News | Shari'ah | Health & Science | Muslim Affairs | Reading Islam | Family | Culture | Youth | Euro-Muslims See similar questions...

No. Earthquakes and tsunamis cannot be predicted. However, once a large earthquake does occur, PTWC can forecast the tsunami behavior if one had been generated. See similar questions...

Yes, but only to a limited extent. Although the process by which tornadoes form is not completely understood, scientific research has revealed that tornadoes usually form under certain types of atmospheric conditions. When forecasters see those conditions, they can predict that tornadoes are likely to occur. However, it is not yet possible to predict in advance exactly when and where they will develop, how strong they will be, or precisely what path they will follow. See similar questions...

Several types of data can be collected to assist hydrologists in predicting when and where floods might occur. The first and most important is the amount of rainfall occurring on a realtime (actual) basis, and second is the rate of change in river stage on a realtime basis. The rate of change can help indicate the severity and immediacy of the threat. See similar questions...

Once an earthquake has occurred, the arrival time of a tsunami, if generated, can be determined accurately. Tsunami wave heights can not be accurately predicted near the earthquake source. Away from the source, tsunami wave heights can be estimated based on mathematical tsunami models and observed wave heights. See similar questions...