3.2-magnitude offshore earthquake recorded off Faro

An earthquake measuring 3.2 on the Richter scale was recorded off the Algarve coast this Thursday morning (July 2), according to the Portuguese Institute for the Sea and the Atmosphere (IPMA).

The tremor’s epicentre was located around 45 kilometres south-southwest of Faro, but the IPMA said it had received no reports that the earthquake was felt.

The latest tremor comes just days after a magnitude 4.1 earthquake was felt in parts of the western Algarve, including Lagos and Portimão, on Sunday. That offshore quake, centred around 70 kilometres west-southwest of Cape St. Vincent, caused no injuries or damage but was felt with a maximum intensity of II/III on the Modified Mercalli scale.

The two events also come at a time when earthquakes have been firmly in the public consciousness following the catastrophic earthquakes that struck Venezuela last week, which have claimed more than 1,900 lives, including dozens of Portuguese nationals and people of Portuguese descent.

Algarve prepared for two earthquake scenarios

While both earthquakes in the Algarve were relatively minor, they have renewed attention on the Algarve’s seismic risk. The region is considered one of Portugal’s most earthquake-prone areas, and the Algarve Regional Civil Protection Authority has been updating its emergency planning for a major seismic event, according to a recent report by SIC.

Authorities currently work with two principal earthquake scenarios: one similar to the devastating 1755 Lisbon earthquake, which would primarily affect the western Algarve, and another centred on the Santo Estêvão fault near Tavira, with the greatest impact expected in the eastern Algarve.

Current emergency planning scenarios estimate that a major earthquake could leave around 2,000 people dead and 30,000 displaced, although Civil Protection has acknowledged those projections are based on older population data and are being updated using the 2021 Census.

The plans also include the possibility of a tsunami, with low-lying coastal areas including the Ria de Alvor, Arade estuary, Albufeira, Loulé, Faro, Olhão and Vila Real de Santo António identified as particularly vulnerable.

According to Civil Protection, residents could have as little as 10 to 15 minutes between a major offshore earthquake and the arrival of a tsunami, making it essential that people recognise warning signs and know evacuation routes. Several Algarve municipalities have already installed tsunami evacuation signage and carried out emergency drills.

The SIC report also highlighted concerns about the resilience of critical infrastructure. Civil Protection scenarios envisage possible disruptions to sections of the EN125 and Via do Infante (A22), as well as damage to hospitals and health centres that could complicate emergency response efforts.

Structural engineering experts cited by SIC also warn that inadequate inspection of construction work could increase the impact of a major earthquake, arguing that stricter enforcement of Portugal’s seismic building regulations is needed.

Michael Bruxo

Journalist for the Portugal Resident.