A 4.1 magnitude earthquake was felt across parts of the Lisbon region early Thursday afternoon after a tremor struck near Alenquer in the Lisbon district. The seismic event was recorded at 12:14 pm local time and originated approximately four kilometres west northwest of the town of Alenquer at a depth of 15 kilometres, according to Portugal’s national seismic monitoring authorities.
The earthquake was widely felt but did not result in any reported injuries or material damage. Initial assessments from emergency services confirmed that the tremor caused concern among residents but did not trigger structural incidents or emergency interventions.
The strongest intensity was registered in the municipality of Loures, where the quake reached level IV to V on the modified Mercalli intensity scale. At this level, shaking can be clearly felt indoors, with some objects moving and windows rattling, but structural damage is generally unlikely.
Residents in several other municipalities also reported feeling the tremor with lower intensity. These included Lisbon, Sintra, Torres Vedras, Vila Franca de Xira, Almada and Barreiro, as well as Alenquer itself. Outside the Lisbon district, reports came in from Montemor o Novo in Évora, Peniche in Leiria, Benavente in Santarém and parts of the Coimbra district.
12:30 pm, authorities had gathered multiple confirmations from across central Portugal, indicating that the seismic activity was perceptible across a broad area. Despite the geographical spread of reports, officials reiterated that there were no signs of structural compromise, infrastructure disruption or casualties linked to the event.
Portugal’s National Emergency and Civil Protection Authority advised residents to remain attentive, particularly in areas that have recently experienced adverse weather conditions. Authorities highlighted that heavy rainfall and storms in recent weeks may have weakened slopes or older structures in certain locations. As a precaution, citizens were urged to exercise additional care in zones previously affected landslides or structural instability.
Portugal is situated near the boundary between the Eurasian and African tectonic plates, making it moderately prone to seismic activity. While most earthquakes recorded in mainland Portugal are of low to moderate magnitude, they can still be felt across wide areas depending on depth and location.
Seismologists continue to monitor aftershocks or any additional activity related to the Alenquer tremor. At this stage, no further significant seismic movements have been recorded in connection with the event.
Local authorities remain in coordination with civil protection teams to ensure readiness in the event of further developments, while reassuring the public that current assessments indicate no ongoing risk.
