Earthquakes near San Luis Río Colorado through history

The deadliest was not the strongest: a magnitude 6.9 on May 19, 1940 (The 1940 Imperial Valley, California Earthquake), for which NOAA records 9 deaths. NOAA’s list of significant earthquakes has 12 here, back to 1852. NOAA records deaths in 5 of the events here, 19 in all. NOAA’s record here begins on November 29, 1852 with an earthquake. 3 of the 12 significant earthquakes NOAA lists here came before 1927.

• April 4, 2010Earthquake · M 7.2The 2010 Sierra El Mayor, B.C., Mexico Earthquake · 2 deaths (NOAA)USGS · NOAA NCEI · Wikipedia
• May 19, 1940Earthquake · M 6.9The 1940 Imperial Valley, California Earthquake · 9 deaths (NOAA)USGS · NOAA NCEI · Wikipedia
• December 31, 1934Earthquake · M 7.1Baja,Imperial ValleyNOAA NCEI
• November 29, 1852Earthquake · M 7.0 (est.)NOAA NCEI

• An event counts for San Luis Río Colorado when it began within 100 km of its centre, or 200 km for an earthquake of magnitude 7 or more. Damage can reach further.
• 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.
• 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