Reviewed by USGSOregon35y ago
M4.3 earthquake 188 km W of Port Orford, Oregon
Sunday, July 14, 1991, 21:23:38 UTC · 42.449°N, 126.761°W
A magnitude 4.3 earthquake struck 188 km W of Port Orford, Oregon on Sunday, July 14, 1991, 21:23:38 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 10 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
17 km
from the nearest mapped plate boundary, between the Pacific and Juan de Fuca plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 200 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.4123 km W of Big Lagoon, CaliforniaJanuary 31, 1922 · 170 km SE of this epicenter
- 7.2The 1980 Eureka, California EarthquakeNovember 8, 1980 · 255 km SE of this epicenter
- 7.1The 1923 Humboldt County, California EarthquakeJanuary 22, 1923 · 262 km SE of this epicenter
- 6.9103 km W of Pistol River, OregonJuly 13, 1991 · 97 km E of this epicenter
- 6.8123 km W of Ferndale, CaliforniaNovember 25, 1954 · 239 km S of this epicenter
- 6.884 km W of Ferndale, CaliforniaFebruary 9, 1941 · 236 km SE of this epicenter
- 6.8off the coast of Northern CaliforniaJuly 6, 1934 · 174 km SE of this epicenter
- 6.7217 km W of Ferndale, CaliforniaSeptember 10, 1984 · 216 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2 recorded deaths. The most severe:
- 1954M6.6
Humboldt County
21 Dec 1954 · 298 km away
1 death$2 million damage
- 1932M6.5
Eureka
6 Jun 1932 · 281 km away · intensity VIII
1 deathModerate damage ($1–5M)
- 1980M7.2
North Coast
8 Nov 1980 · 255 km away · intensity VII
$2 million damage
- 1865
Fort Humboldt, Eureka
1 Oct 1865 · 247 km away · intensity IX
Moderate damage ($1–5M)
- 1922M7.6
Northern
31 Jan 1922 · 192 km away
Limited damage (under $1M)
- 1923M7.1
Northern
22 Jan 1923 · 262 km away · intensity VIII
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.