Earthquake

Earthquakes can cause affected areas to increase or decrease in elevation by several feet, which can in turn lead to flooding in coastal areas. Port Royal, on the south shore of Jamaica, subsided several feet in an earthquake in 1692 and suddenly disappeared as the sea rushed into the new depression. Eyewitnesses recounted the seismic destruction of the infamous pirate anchorage as follows: "... in the space of three minutes, Port-Royall, the fairest town of all the English plantations, exceeding of its riches,... was shaken and shattered to pieces, sunk into and covered, for the greater part by the sea.... The earth heaved and swelled like the rolling billows, and in many places the earth crack'd, open'd and shut, with a motion quick and fast... in some of these people were swallowed up, in others they were caught by the middle, and pressed to death.... The whole was attended with... the noise of falling mountains at a distance, while the sky... was turned dull and reddish, like a glowing oven." Ships arriving later in the day found a small shattered remnant of the city that was still above the water. Charts of the Jamaican coast soon appeared printed with the words "Port Royall Sunk." During the New Madrid (Missouri) earthquake of 1811, a large area of land subsided around the bed of the Mississippi River in west Tennessee and Kentucky. The Mississippi was observed to flow backwards as it filled the new depression and created what is now known as Reelfoot Lake. The last great earthquake in the U.S. Pacific Northwest occurred two years before Port Royal sank in 1690. In the 300 years since then, no major earthquake has released the potential energy that has been building under the crust. Geologists have found buried forests and deposits indicating that coastal areas were periodically flooded, probably as the result of major earthquakes.