During an earthquake near port royal, jamaica, the water-saturated sand on which the city was built vigorously shook. as a result, the sand particles lost contact with one another, giving the mixture the consistency of a thick milk shake. anything supported by the ground, such as buildings and people, either floated or sank. one eyewitness stated: "whole streets with inhabitants were swallowed up. . some were swallowed quite down, and cast up again by great quantities of water; others went down and were never more seen." this is a description of