Earthquakes in Puerto Rico through history

The deadliest was not the strongest: a magnitude 7.1 on October 11, 1918 (24 km NNW of San Antonio, Puerto Rico), for which NOAA records 144 deaths. NOAA’s list of significant earthquakes has 20 here, back to 1717. NOAA records deaths in 3 of the events here, 172 in all. The latest on NOAA’s list is a magnitude 5.4 on May 2, 2020 (6 km S of Tallaboa, Puerto Rico). NOAA’s record here begins in 1717 with an earthquake (Arecibo). 14 of the 20 significant earthquakes NOAA lists here came before 1927. NOAA lists 9 tsunamis that began in or off Puerto Rico. The highest water NOAA records here was 6.1 m, on November 18, 1867. The deadliest, on October 11, 1918, killed 140 people here by NOAA’s runup records.

• May 2, 2020Earthquake · M 5.46 km S of Tallaboa, Puerto RicoUSGS · NOAA NCEI
• January 7, 2020Earthquake · M 6.44 km SSE of Indios, Puerto Rico · 4 deaths (NOAA)USGS · NOAA NCEI · Wikipedia
• July 29, 1943Earthquake · M 7.745 km N of San Antonio, Puerto RicoUSGS · NOAA NCEI · Wikipedia
• October 11, 1918Earthquake · M 7.124 km NNW of San Antonio, Puerto Rico · 144 deaths (NOAA)USGS · NOAA NCEI · Wikipedia
• October 11, 1918Tsunami · 6 m hereMona Passage · 140 deaths here (NOAA)NOAA NCEI · Wikipedia
• July 27, 1917Earthquake · M 6.894 km NE of Punta Cana, Dominican RepublicUSGS
• April 24, 1916Earthquake · M 6.826 km SE of Boca de Yuma, Dominican RepublicUSGS · NOAA NCEI
• November 18, 1867Earthquake · M 7.3 (est.)24 deaths (NOAA)NOAA NCEI · Wikipedia
• November 18, 1867Tsunami · 6.1 m hereVirgin IslandsNOAA NCEI · Wikipedia
• 1717EarthquakeAreciboNOAA NCEI

• An event counts for Puerto Rico 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 Puerto Rico 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 Puerto Rico, 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