Reviewed by USGSCalifornia Earthquake122y ago
M7.9 earthquake in The 1906 San Francisco, California Earthquake
Wednesday, April 18, 1906, 13:12:26 UTC · 37.750°N, 122.550°W
A magnitude 7.9 earthquake struck in The 1906 San Francisco, California Earthquake on Wednesday, April 18, 1906, 13:12:26 UTC, at a depth of 11.7 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.9
- Major · mw
- Depth
- 12 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- IX
- Violent (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
11 megatons of TNT
That is about 709 times the Hiroshima bomb. It released about 22,387 times the energy of a magnitude 5.0.
Tectonic setting
3 km
from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
12 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists no earlier M5.0+ earthquakes within 300 km.
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 22 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 730 recorded deaths. The most severe:
- 1906M7.9
San Francisco
18 Apr 1906 · 11 km away · intensity XI
700 deaths$400 million damagetsunami
- 1868M6.8
Hayward,San Francisco
21 Oct 1868 · 40 km away · intensity IX
30 deathsUnder $1 million damagetsunami
- 1858
San Jose,San Francisco
26 Nov 1858 · 56 km away · intensity IX
Severe damage ($5–24M)
- 1861
Contra Costa,Alameda Counties
4 Jul 1861 · 56 km away · intensity XI
Severe damage ($5–24M)
- 1898M6.5
Sonoma County
31 Mar 1898 · 52 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1892M6.2
Winters
21 Apr 1892 · 101 km away · intensity IX
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.