Earthquakes near Kochi, Japan through history

The deadliest was not the strongest: an estimated magnitude 8.4 on October 28, 1707 (Nankaido), for which NOAA records 5,000 deaths. NOAA’s list of significant earthquakes has 15 here, back to AD 684. NOAA records deaths in 8 of the events here, 16,268 in all. The latest on NOAA’s list is a magnitude 7.5 on April 1, 1968 (60 km ESE of Nobeoka, Japan). NOAA’s record here begins on November 29, 684 with an earthquake. It grows thinner going back: 3 of the 15 significant earthquakes NOAA lists here are from 1927 on. NOAA lists 2 tsunamis that began within 100 km of Kochi, Japan, and 10 from elsewhere that reached it with deaths or a metre of water or more. The highest water NOAA records here was 28 m, on December 24, 1854. The deadliest here came on October 28, 1707 from a magnitude 8.4 earthquake (Nankaido): NOAA’s runup records count 1,885 deaths within 100 km of Kochi, Japan.

• April 1, 1968Earthquake · M 7.560 km ESE of Nobeoka, Japan · one death (NOAA)USGS · NOAA NCEI · Wikipedia
• December 24, 1854Tsunami · 28 m hereNankaido · 1,120 deaths here (NOAA)NOAA NCEI · Wikipedia
• October 28, 1707Earthquake · M 8.4 (est.)Nankaido · 5,000 deaths (NOAA)NOAA NCEI · Wikipedia
• October 28, 1707Tsunami · 25.7 m hereNankaido · 1,885 deaths here (NOAA)NOAA NCEI · Wikipedia
• August 26, 887Earthquake · M 8.6 (est.)NankaidoNOAA NCEI
• November 29, 684Earthquake · M 8.4 (est.)NOAA NCEI · Wikipedia

• An event counts for Kochi, Japan 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