Earthquake near Boulder City, NV

USGS: 18 km ESE of Boulder City, Nevada

66 km (41 mi) ESE of Las Vegas, NV · 36 km (22 mi) ESE of Henderson, NV

1:40 pm PDT, Oct 23, 2018 · 2018-10-23 20:40 UTC · 8.9 km deep · released about 5.4 lb of TNT

Every earthquake near Boulder City Felt it? Tell USGS Check my area

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: 1:40 pm PDT on 23 October 2018 (2018-10-23 20:40 UTC)
Where: 19 km (12 mi) ESE of Boulder City, NV · earthquakes near Boulder City
Magnitude: M 1.5 (ml)
Depth: 8.9 km below the surface
Felt: no reports yet
Nearest: Clark County, 48 km NW
Status: Reviewed by a seismologist

USGS · last changed by USGS 2901 days ago · we first saw it 2901 days ago

A magnitude 1.5 earthquake was recorded 19 km (12 mi) ESE of Boulder City, NV, at 1:40 pm PDT on 23 October 2018 (20:40 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
Around the size people start to feel M 3.0 180× the energy of this one
This earthquake M 1.5 about 5.4 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 one earthquake of M5 or more within 50 km:

5.0 1 km SE of Boulder City, Nevada · 17 km WNW of this epicentre May 4, 1939

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

Map loads when it scrolls into view

Epicentre 35.9027, -114.6484. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction from the epicentre
Clark County, NV	48 km (30 mi)	NW	earthquakes near Clark County
Mohave County, AZ	84 km (52 mi)	ESE	earthquakes near Mohave County

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

Aftershocks so far

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

1.6 11 km ENE of Henderson, Nevada 21:53 UTC
1.6 9 km NE of Whitney, Nevada 16:00 UTC
1.6 10 km SSE of Enterprise, Nevada 21:35 UTC
1.7 9 km ENE of Whitney, Nevada 21:00 UTC
1.6 8 km SSE of Paradise, Nevada 14:18 UTC
1.7 9 km WSW of Henderson, Nevada 23:42 UTC
1.6 8 km SSW of Henderson, Nevada 21:00 UTC
1.8 18 km E of Nellis Air Force Base, Nevada 10:39 UTC
2.1 14 km SSE of Enterprise, Nevada 22:20 UTC
1.8 18 km NE of White Hills, Arizona 02:28 UTC
2.4 11 km ESE of Enterprise, Nevada 21:50 UTC
1.8 8 km SSW of Whitney, Nevada 21:19 UTC
1.9 8 km SE of Enterprise, Nevada 22:21 UTC
1.9 10 km NW of Meadview, Arizona 04:11 UTC
2.2 7 km WNW of Meadview, Arizona 17:35 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 02:10 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.