Reviewed by USGSOregon42y ago
M4.2 earthquake 260 km WNW of Bandon, Oregon
Wednesday, March 13, 1985, 20:19:58 UTC · 43.711°N, 127.526°W
A magnitude 4.2 earthquake struck 260 km WNW of Bandon, Oregon on Wednesday, March 13, 1985, 20:19:58 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.2
- 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
30 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 lists 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on March 14, 1985. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 105 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.5259 km W of Bandon, OregonMarch 13, 1985 · 23 km S of this epicenter
- 6.5235 km W of Port Orford, OregonAugust 5, 1910 · 106 km S of this epicenter
- 6.4213 km W of Port Orford, OregonAugust 20, 1952 · 99 km S of this epicenter
- 6.4169 km W of Crescent City, CaliforniaMarch 24, 1949 · 263 km SE of this epicenter
- 6.4187 km W of Trinidad, CaliforniaDecember 31, 1915 · 296 km S of this epicenter
- 6.4off the coast of OregonSeptember 11, 1928 · 244 km W of this epicenter
- 6.3off the coast of OregonMay 8, 1968 · 51 km W of this epicenter
- 6.3off the coast of OregonSeptember 25, 1936 · 147 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1700M9.0
Cascadia Subduction Zone
27 Jan 1700 · 247 km away
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.