The April 26, 1973 earthquake
M6.2near Honomu, Hawaii
A magnitude 6.2 earthquake 22.9 miles deep, centred in Hawaii County. The 13th strongest in Hawaii’s record since 1900, and the strongest within 50 miles since a magnitude 6.4 on June 16, 1940. 44 aftershocks of magnitude 2.5 or more followed within 30 days.
Watch the sequence unfoldMagnitude 6.2 · April 26, 1973
How the ground moved
Every recorded earthquake in the sequence, in order, through the month after.
The earthquake
- Magnitude
- 6.2
- surface-wave magnitude (ms)
- Depth
- 22.9 mi
- 36.9 km below the surface
- Local time
- Thursday, April 26, 1973
- 10:26 HST; 20:26 UTC
- In Hawaii’s record
- 13th
- strongest of 39,637 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event hv19730624 (“3 km WSW of Honomu, Hawaii”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Aftershocks
Earthquakes of magnitude 2.5 or more within 20 miles of the epicentre in the 30 days after.
44
Aftershocks in 30 days
3.8
Largest aftershock, May 5, 1973
14
On the first day
0
In the 7 days before
- The search radius is the surface rupture length expected for an earthquake of this magnitude (Wells and Coppersmith, 1994), at least 20 and at most 600 miles, so a great earthquake's sequence is counted along its whole fault.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Hawaii CountyHI · inside
Earthquakes around the epicentre
6,143 earthquakes of magnitude 3 or more within 50 miles of this epicentre since 1973.
Earlier earthquakes of magnitude 5 or more within 50 miles, strongest first
- September 20, 1908M6.7
- June 16, 1940M6.4
- March 28, 1915M6.4
- November 1, 1918M6.2
- May 3, 1905M6.2
- June 27, 1962M6.2
- March 30, 1954M6.1
- March 20, 1927M6.0
- March 19, 1926M6.0
- January 2, 1935M5.9
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.