QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near North Portland, OR

USGS: 5 km NW of North Portland, Oregon

14 km (9 mi) NW of Portland, OR · 12 km (8 mi) W of Vancouver, WA

11:49 pm PST, Mar 8, 2018 · · 18 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Clark County 25 kmMultnomah County 28 kmWashington County 28 kmColumbia County 42 kmCowlitz County 62 kmYamhill County 62 kmClackamas County 69 kmSkamania County 75 kmTillamook County 81 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
11:49 pm PST on 8 March 2018 ()
Where
6 km (3 mi) NW of North Portland, OR · earthquakes near North Portland
Magnitude
M 1.6 (ml)
Depth
18 km below the surface
Felt
no reports yet
Nearest
Clark County, 25 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3126 days ago

A magnitude 1.6 earthquake was recorded 6 km (3 mi) NW of North Portland, OR, at 11:49 pm PST on 8 March 2018 (07:49 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Lake Shore, Vancouver, Hazel Dell, Felida, Minnehaha, Salmon Creek.

How big was it?

This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.2 5 km E of Bridgeton, Oregon · 13 km ESE of this epicentre
  2. 5.0 3 km SW of Portland, Oregon · 17 km SSE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 45.6442, -122.7557. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Clark County, WA 25 km (16 mi) NE earthquakes near Clark County
Multnomah County, OR 28 km (18 mi) ESE earthquakes near Multnomah County
Washington County, OR 28 km (18 mi) WSW earthquakes near Washington County
Columbia County, OR 42 km (26 mi) NW earthquakes near Columbia County
Cowlitz County, WA 62 km (38 mi) N earthquakes near Cowlitz County
Yamhill County, OR 62 km (39 mi) SW earthquakes near Yamhill County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

58 earthquakes have been recorded within 50 km since this one.

  1. 1.6 3 km WSW of Yacolt, Washington
  2. 1.6 5 km SW of Deer Island, Oregon
  3. 1.5 3 km SW of Yacolt, Washington
  4. 1.6 2 km E of Sherwood, Oregon
  5. 1.7 6 km ENE of Prescott, Oregon
  6. 1.7 13 km ESE of Yacolt, Washington
  7. 1.5 3 km SSW of Beaverton, Oregon
  8. 1.9 3 km WSW of Dundee, Oregon
  9. 2.2 3 km ESE of Woodland, Washington
  10. 1.6 16 km ENE of Kalama, Washington
  11. 1.8 0 km SW of Kalama, Washington
  12. 1.6 1 km SSW of Cherry Grove, Washington
  13. 1.5 4 km NW of North Portland, Oregon
  14. 1.5 Washington-Oregon border region
  15. 1.5 4 km W of Mulino, Oregon

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.