The small Caribbean island of Jamaica is not one you usually associate with quakes but it does in fact transverse several fault lines. It lays where the Caribbean plate is moving westward relative to the Gonâve microplate with the main fault lines being the Enriquillo-Plantain garden fault zone in the east and the Walton fault zone to the west. The faults cause an average of 200 – 400 minor quakes a year on the island and is a part of the same fault system which cause the devastating Haiti quake of 2010. Jamaica its self has had a fair few big earthquakes, luckily there tends to be around 100 years between events. January 14th 1907 was one of the worst in recent history.
At 3.30pm local time a magnitude 6.5 earthquake along the sinstral strike-slip fault. Every house in Kingston was damaged and a local tsunami was triggered causing waves 6-8 ft crashing in to the northern coastline. Fires raged for hours after hindering rescue attempts for people trapped under the collapsed buildings.
It is estimated between 800 to 1100 people were killed although even official death tolls varied greatly. Over 10,000 were left homeless and over $25,00 000 worth of damage was caused leading it to be refered to as one of Jamaica’s worst natural disasters. Most of the damaged occurred in Kingston, although Buff Bay and Anotto Bay were also badly effected.
The main tremor lasted 35 seconds and was followed almost immeadiatly by a slightly weaker after shock. The only seismograph on the island was actually damaged by the earthquake meaning that magnitude and epicentre had to pretty much be guessed from witness reports. Over 80 aftershocks occurred over the next month pulling down already destroyed buildings. At the time buildings were poorly constructed to withstand any level of earthquake and this was made worse by the bedrock of the area being mainly unconsolidated sands and gravels meaning a greater intensity on the surface and ground deformation.
One positive outcome was the greater awareness of the seismic threat to the island. Building codes were put in place as the city was rebuilt to limit future destruction, earthquake and fire insurance became available to residents and better monitoring systems were put in place. Sadly a full seismic network was not put in place until after the 1957 Montego Bay earthquake.