While minor earthquakes are common in South Carolina, tsunamis are extremely rare.
The most powerful earthquake in recent state history, the 1886 quake that knocked down buildings in Charleston, created a tidal wave that ranged from less than an inch to 20 inches, according to the states 36-page Tsunami Response Plan.
Charleston tide gauge records indicated a small tsunami in South Carolina after a 1929 earthquake off Newfoundland, and geographic historians say a 1755 quake off Portugal caused a tsunami over much of the east coast of North America, according to the International Journal of the Tsunami Society.
The makeup of the Earth's crust under the Atlantic Ocean makes massive tidal waves less likely along the South Carolina coast. The crust under much of the Atlantic is more passive than the massive plates that often push over each other on the Pacific rim and in the Indian Ocean, University of South Carolina geography professor Pradeep Talwani said after the 2004 Indonesian quake.
That doesnt mean South Carolina cant be hit by a big tsunami. There are major plate collisions under Caribbean waters. Also, a scientific study early last decade speculated that a massive tsunami would hit the East Coast if a chunk of the volcanic La Palma in the Canary Islands broke off, but subsequent studies of the La Palma scenario came up with less devastating conclusions.