QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near New Castle, CO

No earthquake was likely felt in New Castle in the 24 hours to 1:24 pm MST (20:24 UTC). The last one was M 5.0, 706 km (439 mi) ESE, at 4:21 am MDT on 23 July 2026, estimated intensity II (weak) in town; 499 felt reports to USGS. Every earthquake near New Castle

This page: a magnitude 2.5 earthquake was recorded 9 km (6 mi) northeast of New Castle, CO, at 5:16 pm MDT on 15 July 2023 (23:16 UTC), 5.0 km deep. 2 people have reported feeling it to USGS.

USGS: 7 km NNW of Chacra, Colorado

5:16 pm MDT, Jul 15, 2023 · · 5.0 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Garfield County 38 kmEagle County 67 kmPitkin County 67 kmRio Blanco County 72 kmDelta County 93 kmRoutt County 102 kmLake County 108 kmMesa County 110 kmGunnison County 114 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
5:16 pm MDT on 15 July 2023 ()
Where
9 km (6 mi) northeast of New Castle, CO · earthquakes near New Castle
Magnitude
M 2.5 (ml)
Depth
5.0 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Garfield County, 38 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1152 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 21 km (13 mi) from the epicentre. In New Castle, 9 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: New Castle 9 km, intensity II · Glenwood Springs 16 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 39.6426, -107.4736. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Garfield County, CO 38 km (23 mi) W earthquakes near Garfield County
Eagle County, CO 67 km (41 mi) E earthquakes near Eagle County
Pitkin County, CO 67 km (42 mi) SE earthquakes near Pitkin County
Rio Blanco County, CO 72 km (45 mi) WNW earthquakes near Rio Blanco County
Delta County, CO 93 km (58 mi) SSW earthquakes near Delta County
Routt County, CO 102 km (64 mi) NNE earthquakes near Routt County

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

Aftershocks so far

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

  1. 2.8 18 km SSE of Meeker, Colorado
  2. 2.2 10 km NW of Dotsero, Colorado
  3. 2.5 30 km NNW of Dotsero, Colorado
  4. 2.6 12 km S of Mulford, Colorado
  5. 2.1 6 km NNW of Chacra, Colorado
  6. 2.5 22 km NNW of New Castle, Colorado
  7. 2.9 6 km NNE of Chacra, Colorado

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.