JACKSONVILLE, Fla. – A confirmed 6.1 magnitude earthquake occurred around 65 miles from Mantua, Cuba around 2 p.m. on Monday.
The United States Geological Survey (USGS) received over 5,500 reports from Mexico to North Florida of people feeling shaking. The highest concentration of reports were over Central and West Florida, closest to the epicenter of the earthquake.
On the Richter Scale (a scale used to measure the total energy released at the source), between 6-6.9 would classify this earthquake as a strong earthquake. The scale goes from 1 to 9.9 and is each whole number represents roughly 32 times more energy.
JaxReady, the city of Jacksonville’s emergency preparedness division, said it received reports from Northeast Florida residents who also said they experienced the aftershock.
On the did you feel it map above, reports are measured using a different scale.
The Modified Mercalli intensity scale measures the effects of an earthquake at a given location.
The strength is notated by roman numeral from 1 to 10. For example, two is weak and seven is very strong. Each intensity category has different examples of damage which can be shown above.
How exactly does the Richter Scale and the Modified Mercalli scale differ?
The Richter Scale strictly measures magnitude or the total energy released by the earthquake from seismographs and the Modified Mercalli Scale measures intensity from eyewitness accounts and structural damage.
The strongest known earthquake in Florida occurred in 1879. A magnitude 4.4 earthquake occurred near Gainesville.
In 1886, a strong earthquake hit Charleston, South Carolina. The strength was estimated to be around 7.0. Impacts were felt here in Georgia and Florida.
Using the modified Mercalli intensity scale, Northeast Florida and Southeast Georgia recorded a value of roughly 6 to 7, indicating strong to very strong.
According to reports, structural damage was reported well away from Charleston, including central Alabama, central Ohio, eastern Kentucky, southern Virginia, and western West Virginia, and long-period effects were observed at distances exceeding 600 miles.
Several other weaker earthquakes have occurred with some being so weak you cant feel them.
Fortunately Florida is not situated near any plate boundaries and the closest fault line is over the Caribbean Sea. However if an earthquake is strong enough, impacts can be observed here like we have seen in the past.