Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Morton, WA
USGS: 17 km S of Morton, Washington
- When
- 6:19 am PDT on 22 July 2018 ()
- Where
- 17 km (11 mi) S of Morton, WA · earthquakes near Morton
- Magnitude
- M 1.8 (ml)
- Depth
- 11 km below the surface
- Felt
- no reports yet
- Nearest
- Lewis County, 21 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2992 days ago
A magnitude 1.8 earthquake was recorded 17 km (11 mi) S of Morton, WA, at 6:19 am PDT on 22 July 2018 (13:19 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
How big was it?
This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 790,000× the energy of this one
- Around the size people start to feel M 3.0 70× the energy of this one
- This earthquake M 1.8 about 14 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 16 earthquakes of M5 or more within 50 km; the five largest:
- 5.7 38 km NNE of Amboy, Washington · 23 km SSE of this epicentre
- 5.2 37 km NNE of Amboy, Washington · 23 km SSE of this epicentre
- 5.2 23 km S of Morton, Washington · 7 km SSE of this epicentre
- 5.1 28 km ENE of Amboy, Washington · 44 km SSE of this epicentre
- 5.1 Washington · 22 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 46.4043, -122.2855. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lewis County, WA | 21 km (13 mi) | NNW | earthquakes near Lewis County |
| Cowlitz County, WA | 38 km (24 mi) | SW | earthquakes near Cowlitz County |
| Skamania County, WA | 49 km (31 mi) | SSE | earthquakes near Skamania County |
| Clark County, WA | 72 km (45 mi) | SSW | earthquakes near Clark County |
| Thurston County, WA | 72 km (45 mi) | NW | earthquakes near Thurston County |
| Pierce County, WA | 73 km (45 mi) | N | earthquakes near Pierce County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 1.6 14 km SSW of Morton, Washington
- 1.6 21 km SSE of Mossyrock, Washington
- 1.8 9 km S of Toledo, Washington
- 1.6 9 km SSE of Toledo, Washington
- 1.6 12 km SSE of Toledo, Washington
- 1.8 8 km E of Ashford, Washington
- 1.6 4 km W of Mossyrock, Washington
- 1.6 6 km SSW of Morton, Washington
- 1.6 6 km ESE of Ashford, Washington
- 2.2 23 km S of Morton, Washington
- 1.6 16 km ENE of Kalama, Washington
- 1.5 6 km SE of Onalaska, Washington
- 2.6 8 km E of Ashford, Washington
- 1.8 23 km SSE of Mossyrock, Washington
- 1.8 24 km N of Amboy, Washington
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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.