The initial British settlement of Jamaica during the latter part of the 17th Century was concentrated on a long sandspit extending across the mouth of Kingston harbour, known as the Palisadoes. This sandspit consisted of a ridge of sand, swept by currents along the coast from rivers to the east, overlying limestone bedrock which is presently some 100 m below sea level. The town of Port Royal was therefore literally built on sand, and water - saturated and very weak sand at that. Nevertheless, the business opportunities derived from servicing the ships (and sailors) at anchor in Kingston harbour meant that by 1692 the 6500 - strong population of the town were both rich and notorious. Archaeological and archival investigations suggest, however, that the reputation of the town as a Caribbean Sodom and Gomorrah derives more from the manner of its demise than its existence.

On 7th June 1692 a violent earthquake shook eastern Jamaica. The location of the earthquake and the fault on which it occurred are not well known. It was however sufficient to liquefy the sand in the lower part of the sandspit and cause it to flow out across Kingston harbour. The upper part of the sandspit, and the town built upon it, subsided bodily by up to several metres. Archaeological excavations have revealed many intact foundations, flagstone floors and roadways, indicating that the sandspit did not completely disintegrate. Nevertheless, about two-thirds of the area of the town was permanently submerged. Furthermore, the earthquake and the submarine sediment flows (possibly also including submarine landslides on the steep slopes outside Kingston harbour) generated a series of tsunami waves - at least three waves were recorded - which swept over the sandspit, carrying ships into the town where their remains have subsequently been excavated by archaeologists. Over two thousand people, or one in three of the population, were killed immediately by the earthquake and tsunami. Many more died subsequently from their injuries and from disease. Accounts vary but between 1000 and 3000 more people may have died in the aftermath of the earthquake, raising the proportional death toll to between 50% and 80% of the pre-earthquake population.

Although the Palisadoes sandspit subsequently reestablished itself and Port Royal was partially rebuilt, the focus of settlement on Jamaica subsequently moved to Kingston, built on higher ground and less unstable foundations. This trend was reinforced by another earthquake in 1703 and a series of damaging hurricanes from 1712 to 1744. A parallel can be drawn between the changing patterns of settlement on Jamaica and events after the 1964 Alaska earthquake, in particular the reconstruction of the town of Valdez on an entirely new site.

The new Palisadoes sandspit was partially liquefied again by an earthquake on January 14th, 1907, which also caused severe damage in Kingston, and around 1200 deaths. Earthquake damage to Port Royal was intense owing to amplification of the seismic waves by the soft sediment, and the extreme westernmost part of the Palisadoes sandspit subsided below sea level, by between 3 and 6 metres. Although the population of Jamaica is vastly greater now than it was at the beginning of the century, let alone than in 1692, the population of Port Royal had declined to around 1800 in the early 1980's. More recently, however, the location of the town at the entrance to Kingston harbour has led to an agreement (1998) to develop Port Royal as a "historical and cultural port of call for cruise ships", through the construction of a pier and tourist centre. There is considerable potential for damage to these facilities and any cruise ships using them in the event of a future severe earthquake, liquifaction event and tsunami. Ironically, one of the economic justifications for the project is the attraction provided by the wealth of archaeological remains from the 17th Century Port Royal, which owe their exceptional preservation to the sudden destruction of that town in 1692.