Tremors Rock the Azores: Third Earthquake in Just Four Hours

Earthquake Strikes the Azores

A magnitude 3.7 earthquake struck the island of Terceira at 3:27 AM on Monday, marking the third tremor in just four hours during an ongoing seismic crisis affecting the Azores region. The Earthquake Information and Volcanic Surveillance Centre of the Azores (CIVISA) reported that the epicenter was located about three kilometers south of Raminho, in the municipality of Angra do Heroísmo.

According to CIVISA, the earthquake was felt predominantly in the western part of Terceira, registering a maximum intensity of V on the Modified Mercalli Scale. The eastern half of the island experienced an intensity of IV/V.

Understanding the Modified Mercalli Scale

The Modified Mercalli Scale measures the intensity of earthquakes based on their effects. An intensity of V is considered strong, with effects such as:

• People being awakened
• Liquids oscillating and possibly spilling
• Objects being displaced or toppled
• Doors swinging open or shut

An intensity of IV is categorized as moderate, causing:

• Suspended objects to sway
• Vibrations similar to heavy vehicle passage
• Windows and doors shaking

Additional Seismic Activity

Earlier in the morning, another tremor measuring 2.6 on the Richter scale was recorded at 1:26 AM, also centered near Serreta. This quake was felt with a maximum intensity of IV in various nearby locations, including Serreta, Raminho, and Biscoitos.

The recent quakes are part of a seismic crisis ongoing in Terceira since June 2022. On June 27, CIVISA raised the alert level for the Santa Bárbara volcano to V3, indicating a reactivation of the volcanic system with signs of heightened activity.

Previous Tremors

The first tremor of the day, measuring 2.6, was felt at 11:32 PM the previous night in the nearby island of Faial, part of the central Azores group.

Stay tuned for further updates on this developing situation.