Magnitude3.1

Reviewed by USGSOregon33y ago

M3.1 earthquake 2 km E of Scotts Mills, Oregon

Friday, March 26, 1993, 17:39:21 UTC · 45.048°N, 122.633°W

A magnitude 3.1 earthquake struck 2 km E of Scotts Mills, Oregon on Friday, March 26, 1993, 17:39:21 UTC, at a depth of 20.4 km (shallow).

Magnitude
3.1
Minor · md
Depth
20 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

674 kg of TNT

That is about 1/22,353 of the Hiroshima bomb. A magnitude 5.0 releases about 708 times more energy.

Tectonic setting

220 km

from the nearest mapped plate boundary, between the Juan de Fuca and North American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

20 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M2.7 on March 27, 1993. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M31h6h1d3d7d14d30dMainshock M3.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 2.74 km E of Scotts Mills, Oregon33y ago · 2 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 28 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 76 recorded deaths. The most severe:

  1. 1980M5.2

    Mt St Helens

    18 May 1980 · 134 km away · intensity V

    61 deaths$2.0 billion damagetsunami

  2. 1949M7.0

    Washington

    13 Apr 1949 · 236 km away · intensity VIII

    8 deaths$25 million damagetsunami

  3. 1965M6.6

    Seattle

    29 Apr 1965 · 263 km away · intensity VIII

    7 deaths$28 million damage

  4. 1993M5.6

    Washington-Oregon Border

    25 Mar 1993 · 2 km away · intensity VII

    $28 million damage

  5. 1700M9.0

    Cascadia Subduction Zone

    27 Jan 1700 · 186 km away

    Severe damage ($5–24M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

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