QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Milwaukie, OR

USGS: 0 km WSW of Milwaukie, Oregon

10 km (6 mi) S of Portland, OR

6:41 pm PDT, Jul 22, 2017 · · 25 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Multnomah County 21 kmWashington County 37 kmClark County 38 kmClackamas County 47 kmYamhill County 57 kmMarion County 61 kmColumbia County 65 kmHood River County 77 kmCowlitz County 84 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
6:41 pm PDT on 22 July 2017 ()
Where
in Milwaukie, OR · earthquakes near Milwaukie
Magnitude
M 1.7 (ml)
Depth
25 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Multnomah County, 21 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3276 days ago

A magnitude 1.7 earthquake was recorded in Milwaukie, OR, at 6:41 pm PDT on 22 July 2017 (01:41 UTC). 1 person has reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Oak Grove, Lake Oswego, Oatfield, Jennings Lodge, Clackamas, Gladstone.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 3 earthquakes of M5 or more within 50 km:

  1. 5.6 4 km E of Scotts Mills, Oregon · 46 km S of this epicentre
  2. 5.2 5 km E of Bridgeton, Oregon · 18 km N of this epicentre
  3. 5.0 3 km SW of Portland, Oregon · 8 km NW 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 45.4452, -122.6437. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Multnomah County, OR 21 km (13 mi) ENE earthquakes near Multnomah County
Washington County, OR 37 km (23 mi) WNW earthquakes near Washington County
Clark County, WA 38 km (24 mi) NNE earthquakes near Clark County
Clackamas County, OR 47 km (29 mi) SE earthquakes near Clackamas County
Yamhill County, OR 57 km (35 mi) WSW earthquakes near Yamhill County
Marion County, OR 61 km (38 mi) S earthquakes near Marion County

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

Aftershocks so far

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

  1. 1.6 7 km SSE of Molalla, Oregon
  2. 1.6 1 km N of West Haven, Oregon
  3. 2.0 7 km SE of Molalla, Oregon
  4. 1.5 11 km NNE of Sandy, Oregon
  5. 1.6 1 km WSW of West Slope, Oregon
  6. 1.6 7 km ESE of Molalla, Oregon
  7. 1.8 8 km SE of Molalla, Oregon
  8. 1.8 7 km ENE of Carlton, Oregon
  9. 1.6 1 km NNE of Saint Helens, Oregon
  10. 1.5 3 km N of Portland, Oregon
  11. 1.6 6 km SSE of Sandy, Oregon
  12. 2.0 4 km SE of Ridgefield, Washington
  13. 2.1 8 km SE of Molalla, Oregon
  14. 1.6 8 km S of Scappoose, Oregon
  15. 1.7 7 km NW of North Portland, 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.