Twin Earthquakes Shake Greater Lisbon as City Still Recovers From Storms
Two earthquakes of magnitude 4.1 struck the Greater Lisbon region within two minutes of each other on Thursday afternoon, rattling nerves in a country still reeling from weeks of devastating storms and flooding.
Two earthquakes of magnitude 4.1 struck the Greater Lisbon region within two minutes of each other on Thursday afternoon, rattling nerves in a country still reeling from weeks of devastating storms and flooding.
The first tremor hit at 12:14 local time, followed by a second at 12:16, both with their epicentre located roughly four kilometres west-northwest of Alenquer, according to the Portuguese Institute of the Sea and Atmosphere (IPMA). The Euro-Mediterranean Seismological Centre confirmed identical magnitudes for both events.
No injuries or structural damage have been reported so far. The Lisbon fire brigade and civil protection authorities in Alenquer confirmed they had received no emergency calls related to the quakes. However, the National Authority for Emergency and Civil Protection issued a precautionary appeal, urging residents in areas previously affected by landslides and structural instability from the recent storms to exercise heightened caution.
Geologist Joao Duarte of the University of Lisbon's Faculty of Sciences explained that the quakes were relatively shallow, occurring at depths of just two and 15 kilometres respectively. "These were relatively superficial earthquakes, which makes them felt much more strongly," he said, noting that the pair could be described as "twin quakes" given their identical magnitude and near-simultaneous occurrence at the same fault.
The tremors were felt across a wide area of the Lisbon metropolitan region, including in office buildings and residential towers where workers and residents reported feeling distinct shaking. Social media filled rapidly with reports from across the capital, Setubal, and the Oeste region.
For the many thousands of newcomers who have settled in Portugal in recent years, the experience may have been unsettling. Portugal sits in a seismically active zone, and Lisbon was famously devastated by a massive earthquake in 1755. Modern building codes, updated significantly since the 1980s, are designed to withstand moderate seismic activity, though older buildings in historic centres remain more vulnerable.
Coming on the heels of storms Kristin, Leonardo, and Marta, which killed 18 people and caused widespread destruction, Thursday's quakes add to a sense of unease across the country. Authorities stressed that the seismic events are unrelated to the weather phenomena but acknowledged the psychological toll on a population already under strain.
IPMA continues to monitor seismic activity in the region. Residents are advised to review their household emergency plans and ensure they know evacuation routes, particularly those living in older buildings or areas prone to ground instability.
