Earthquakes in Portugal through history
From 1900 to October 19, 2026, USGS recorded 11 earthquakes of magnitude 6 or more in or off Portugal. The strongest on either list was a magnitude 8.5, twice: in 61 BCE (Cabo San Vicente) and on November 1, 1755 (Lisbon).
The last 30 days · as of
USGS recorded one earthquake of magnitude 4.5 or more in the area the map frames in the last 30 days.
The latest: magnitude 5.1 on October 20 (39 km W of Mosteiros, Portugal).
What the record holds
The one on November 1, 1755 was the deadliest: NOAA records 50,000 deaths for it. NOAA’s list of significant earthquakes has 57 here, back to 242 BCE. NOAA records deaths in 27 of the events here, 90,151 in all. The latest on NOAA’s list is a magnitude 6.2 on July 9, 1998 (12 km N of Horta, Portugal). NOAA’s record here begins in 242 BCE with an earthquake (Cadiz). It grows thinner going back: 12 of the 57 significant earthquakes NOAA lists here are from 1927 on. NOAA lists 21 tsunamis that began in or off Portugal, and one from elsewhere that reached it with deaths or a metre of water or more. The highest water NOAA records here was 15.2 m, on November 1, 1755. The deadliest, on November 1, 1755, killed 33,000 people here by NOAA’s runup records. NOAA lists 6 significant eruptions of 4 volcanoes in or off Portugal. The largest was Furnas on September 3, 1630, at 4 on the volcanic explosivity index. The deadliest was Sao Jorge on July 9, 1757, which killed 1,053 people by NOAA’s count.
The events
- July 9, 1998Earthquake · M 6.212 km N of Horta, Portugal · 10 deaths (NOAA)USGS · NOAA NCEI
- February 28, 1969Earthquake · M 7.8188 km SW of Sagres, Portugal · 25 deaths (NOAA)USGS · NOAA NCEI · Wikipedia
- February 28, 1968Earthquake · M 7.6NOAA NCEI
- July 9, 1757Eruption · VEI 0Sao Jorge · 1,053 deaths (NOAA)NOAA NCEI · Wikipedia
- November 1, 1755Earthquake · M 8.5 (est.)Lisbon · 50,000 deaths (NOAA)NOAA NCEI · Wikipedia
- November 1, 1755Tsunami · 15.2 m hereLisbon · 33,000 deaths here (NOAA)NOAA NCEI · Wikipedia
- September 3, 1630Eruption · VEI 4Furnas · 200 deaths (NOAA)NOAA NCEI · Wikipedia
- January 26, 1531Earthquake · M 7.7 (est.)Lisbon · 30,000 deaths (NOAA)NOAA NCEI
- October 22, 1522EarthquakeSao Miguel Island · 5,000 deaths (NOAA)NOAA NCEI · Wikipedia
- 61 BCEEarthquake · M 8.5 (est.)Cabo San VicenteNOAA NCEI
- 242 BCEEarthquakeCadizNOAA NCEI
Good to know
- An event counts for Portugal when it began inside its borders, or at sea within 100 km of its coast (so one can count for two neighbours), or further out, up to 300 km, where Portugal is the nearest country.
- USGS counts here start at magnitude 6: the catalogue’s smaller quakes thin out going back, where few instruments listened.
- NOAA lists significant events only: earthquakes that killed, did about $1 million of damage, reached magnitude 7.5 or intensity X, or raised a tsunami, and eruptions and tsunamis by like measures. Magnitudes before 1900 are its estimates from written accounts.
- Deaths are NOAA’s total for each event, wherever people died, its tsunami and fires included. A tsunami counts the dead its runup records give for this place: NOAA’s total for a tsunami includes its source quake’s.
- A tsunami from elsewhere counts where one of its runups killed or rose a metre or more.
- The map frames the box around Portugal, its neighbours’ quakes included, so its count runs higher than this page’s.
- Counted to October 19, 2026, as is the map. The last 30 days ask USGS again.
How the layers work, where their data comes from and what they can’t tell you: Earthquakes, live, The world through history