What cities in the us Virgin Islands are earthquake prone?

Answer 1

All cities in the Virgin Islands are earthquake prone. The islands consists of four legal towns: Christiansted and Fredriksted on St. Croix, Cruz Bay on St. John and Charlotte Amalie on St. Thomas. There are quite a number of other densely populated communities, many with much more inhabitants than the cities.

The Virgin Islands is the second most earthquake prone region in the United States of America, California, of course, being number one. On average, the Virgin Islands may experience three to four earthquakes a day. Most are below 4.0 and not felt by the average person.

Most of the Virgin Islands (District of St. Thomas-St. John) is on the Caribbean Ridge, a mostly undersea chain of volcanic mountains bordering the south Atlantic plate. St. Croix and the three other islands in the St. Croix District are on the South American plate which is slowly forcing its way beneath the Atlantic/Caribbean plate.

This movement causes frequent undersea tremors, typically epi-centered just a few miles north or west of St. Thomas. St. Thomas experienced two tsunamis in the 1800's as a result of undersea earthquakes. The city of Charlotte Amalie took the brunt of both tsunamis.

All areas of the Virgin Islands are equally vulnerable to earthquake activity. More government concern is focused of the threat of tsunami. All four cities in the Virgin Islands are coastal communities with larges areas at sea level and some slightly below. There are structures built on filled land, creating the concern that earthquakes cause filled land to vibrate like Gelatin, destabilizing foundations.

Real time information and email alerts on Virgin Islands earthquake activity can be obtained through a local government agency called VITEMA (Virgin Island Emergency Management Agency). See the related link for their website.