Earthquake near Rochester, WA

A magnitude 1.6 earthquake was recorded in Rochester, WA, at 1:24 pm PDT on 27 September 2017 (20:24 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Grand Mound, Fords Prairie, Centralia, Tenino, Chehalis, Tumwater.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 8.1 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 1,900,000× the energy of this one
2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
3. Around the size people start to feel M 3.0 120× the energy of this one
4. This earthquake M 1.6 about 8.1 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 5 earthquakes of M5 or more within 50 km:

1. 6.8 The 2001 Nisqually, Washington Earthquake · 47 km NE of this epicentre Feb 28, 2001
2. 6.7 4 km WNW of Roy, Washington · 44 km ENE of this epicentre Apr 13, 1949
3. 5.8 8 km N of Satsop, Washington · 39 km NW of this epicentre Jul 3, 1999
4. 5.1 Olympic Peninsula, Washington · 48 km NNW of this epicentre Oct 27, 1940
5. 5.0 18 km N of Satsop, Washington · 49 km NW of this epicentre Jun 10, 2001

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 46.8182, -123.1037. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.6 12 km ENE of McCleary, Washington 19:15 UTC
2. 1.6 11 km S of Shelton, Washington 21:59 UTC
3. 1.5 4 km N of McCleary, Washington 02:11 UTC
4. 1.5 8 km WSW of Napavine, Washington 19:18 UTC
5. 1.8 5 km NNW of Winlock, Washington 22:43 UTC
6. 1.7 4 km ENE of Elma, Washington 20:22 UTC
7. 1.6 1 km W of Winlock, Washington 19:34 UTC
8. 1.8 6 km NW of Winlock, Washington 19:23 UTC
9. 1.9 3 km WNW of Winlock, Washington 20:15 UTC
10. 1.6 11 km S of Shelton, Washington 19:29 UTC
11. 1.9 2 km NE of Tanglewilde-Thompson Place, Washington 20:15 UTC
12. 2.0 13 km WSW of Longbranch, Washington 09:44 UTC
13. 1.6 11 km S of Shelton, Washington 21:05 UTC
14. 1.5 3 km W of Winlock, Washington 20:11 UTC
15. 1.7 3 km W of Winlock, Washington 22:26 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 02:54 UTC. 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.