fault lines and tectonic shifts
Imagine two giant plates, called tectonic plates, floating on Earth's surface. These are constantly moving at a very slow rate measured in centimeters per year. They interact in various ways, rubbing against each other, colliding, or even pulling apart. Jamaica sits precisely where two of these plates, the Gonâve microplate and the Caribbean Plate, meet. Over millions of years, this continuous movement has fractured Jamaica's crust into distinct blocks, much like a puzzle breaking apart.
However, the sideways movement of these blocks isn't the only force at play. When the blocks encounter resistance or obstacles, they can no longer move sideways so they are forcefully pushed upwards. This upward movement is responsible for the formation of mountains and the overall elevation of the island. This is how Jamaica emerged from the ocean, and the process continues to this day, as evidenced by a slow but steady rise of the Blue Mountains.
These fractures in the Earth's crust are called faults, and they are the primary locations for earthquakes. In Jamaica, most seismic activity occurs along these faults, particularly the Plantain Garden and Blue Mountains faults. While there are also faults in central Jamaica, they are not as active.
The following video explains the process and the impact to Jamaica.
For more information on the Port Royal 1692 earthquake and some of the graphics featured about the devastation, see Port Royal - a Fiwi Roots Website.