An earthquake was recorded by CIVISA at 18:31 local time (19:31 in Lisbon) with a magnitude of 2.0 on the Richter scale. The epicenter was approximately three kilometers west-northwest (WNW) of Furnas on São Miguel Island.
“Based on available information, the earthquake was felt with a maximum intensity of III/IV (Modified Mercalli Intensity Scale) in the parish of Furnas,” CIVISA reports.
The Richter scale categorizes earthquakes by magnitude: micro (less than 2.0), very minor (2.0-2.9), minor (3.0-3.9), light (4.0-4.9), moderate (5.0-5.9), strong (6.0-6.9), major (7.0-7.9), great (8.0-8.9), exceptional (9.0-9.9), and extreme (greater than 10).
The Modified Mercalli Intensity Scale measures “degrees of intensity and respective description”.
With an intensity of III, considered weak, the tremor is felt indoors with swinging hanging objects and a “vibration similar to that caused by the passage of heavy vehicles,” according to the Instituto Português do Mar e da Atmosfera on its website.
At an intensity of IV, deemed moderate, “suspended objects sway, the vibration is akin to the passage of heavy vehicles or the sensation of a heavy ball hitting walls, parked cars rock, windows, doors, and china rattle, glass and china clink or tinkle, and at the upper end of this intensity, walls and wooden structures creak,” states the IPMA.
