The 5.4-magnitude earthquake, centered in the Atlantic Ocean about 64 kilometers southwest of Sesimbra, occurred at 5:11 a.m. local time.
The shallow earthquake, with a depth of approximately 17 kilometers below the seabed, was the strongest in the region in 15 years. Residents in Lisbon and nearby cities reported feeling strong shaking that woke them from sleep.
The U.S. Geological Survey (USGS) confirmed the earthquake's magnitude and location. (ILKHA)