The IPMA has indicated that it is not possible to establish a link between the earthquake of magnitude 3.0 on the Richter scale recorded and felt today near Sesimbra with the quake that occurred on August 26.
Anearthquake with a magnitude of 3.0 on the Richter scale was recorded at 02:26 today with an epicenter around 30 kilometers from Sesimbra, in the Setúbal district, in a submerged area, without causing any personal or material damage. Previously, the Portuguese Institute for the Sea and Atmosphere (IPMA) had put the magnitude at 3.1.
The quake was felt with low intensity, possibly with a maximum grade of III (Modified Mercalli scale) in the municipalities of Setúbal, Sines and Sesimbra, and other places in the Lisbon district.
The IPMA stressed that the event is part of the “normal activity of the territory and is not indicative of an increase in seismicity in Portugal”.
“It should be noted that it is not possible to establish a link between this earthquake and the one that occurred on August 26,” reads the statement.
On that day, an earthquake with a magnitude of 5.3 on the Richter scale was recorded at 05:11, 58 kilometers west of Sines (also in the Setúbal district), and caused no victims or material damage, with aftershocks following.
This earthquake, according to the IPMA, caused no personal or material damage and was felt with a maximum intensity of IV/V (Modified Mercalli scale) in the Sines region and with less intensity in the Setúbal and Lisbon areas.
According to the Richter scale, earthquakes are classified according to their magnitude as micro (less than 2.0), very small (2.0-2.9), small (3.0-3.9), slight (4.0-4.9), moderate (5.0-5.9), strong (6.0-6.9), large (7.0-7.9), important (8.0-8.9), exceptional (9.0-9.9) and extreme (when greater than 10).
The Modified Mercalli scale measures “degrees of intensity and their description”.
With an intensity of IV, considered moderate, “suspended objects sway, the vibration is similar to that caused by the passage of heavy vehicles or the sensation of a heavy ball hitting the walls, parked cars sway, windows, doors and crockery shake, glass and crockery rattle or clink and at the top of this degree walls and wooden structures creak,” the institute describes on its website.
At intensity III, which is considered weak, the tremor is felt inside the house and hanging objects shake, feeling a “vibration similar to that caused by the passage of heavy vehicles”.
