Title: Tsunami: Maine's Geologic Hazards: Maine Geological Survey: Maine ACF
Headings: Tsunamis in the Atlantic Ocean
Tsunamis in the Atlantic Ocean
Background
What is a tsunami?
How big can tsunami get?
What was the most devastating recorded tsunami?
Tsunamis in the Atlantic Ocean and Caribbean Sea
Large Historic Tsunamis in the Atlantic Ocean and Caribbean Sea (abbreviated list)
Tsunamis in the Gulf of Maine
Tsunami Threat to the East Coast of the United States and New England
Caribbean Islands - Earthquakes and Volcanic Eruptions
North Carolina/Virginia Continental Shelf - Submarine Landslide
Volcanic Eruption and Landslide - La Palma, Canary Islands
Tsunami Monitoring Systems
So should we be worried in Maine?
Selected Bibliography
Originally published on the web as the January 2005 Site of the Month.

Content: Its height is simply the excess height of the tsunami wave (crest) over the normal ocean level as it passes a given point. Its runup distance is the distance from the normal tide line, or shoreline, at the time of the tsunami's arrival to its maximum extent inland. The runup height is the elevation of the point of maximum runup above the normal ocean surface at the time of the tsunami (Figure 4). Figure 4. When the tsunami encounters the coastline, it breaks, surging water forward. Note the runup distance and height in relation to the normal sea level ( adapted from USGS ). The effect a tsunami has on a coastline also depends on the the origin of the tsunami, distance from its point of origin, its size, and the slope and configuration of the bathymetry and coast that the tsunami is approaching. Because of the long period of tsunamis, they can bend around obstacles such as islands, bays, and gulfs. They typically arrive at a coast in the form of suddenly decreasing then rapidly increasing water levels, bore-like waves (similar to a tidal bore), several large breaking waves, or a combination. Tsunamis rarely arrive as a giant breaking wave, as is most commonly depicted, but generally arrive as forceful and rapid increases in water level that violently flood the coastline.