QuakeIndex

volcanic eruption · reviewed by a seismologist

M 4.9mw

Earthquake near Volcano, HI

No earthquake was likely felt in Volcano in the 24 hours to 2:22 am HST (12:22 UTC). The last one was M 1.9, 6 km (4 mi) W, at 11:09 am HST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Volcano

No: USGS classifies this as a volcanic eruption, not an earthquake. A magnitude 4.9 volcanic eruption was recorded 6 km (4 mi) southwest of Volcano, HI, at 11:50 am HST on 20 May 2018 (21:50 UTC), less than 1 km deep. 3 people have reported feeling it to USGS.

USGS: 6 km SW of Volcano, Hawaii

38 km (23 mi) SSW of Hilo, HI

11:50 am HST, May 20, 2018 · · 0.0 km deep · released about 340 tons of TNT

Every earthquake near Volcano Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hawaii County 32 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
11:50 am HST on 20 May 2018 ()
Where
6 km (4 mi) southwest of Volcano, HI · earthquakes near Volcano
Hawaii today
every earthquake in Hawaii in the last 24 hours
Magnitude
M 4.9 (mw)
Depth
0.0 km below the surface
Felt
3 reports · strongest reported intensity III
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
Hawaii County, 32 km NW
Nearest mapped fault
Koa'e fault system, 5 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3013 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 181 km (112 mi) from the epicentre. In Volcano, 6 km away, the estimate is intensity V (moderate). 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: Volcano 6 km, intensity V · Mountain View 25 km, intensity IV · Pāhala 31 km, intensity IV · Hawaiian Paradise Park 38 km, intensity IV · Leilani Estates 39 km, intensity IV · Hilo 41 km, intensity III. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as volcanic eruption, not an earthquake.

How big was it?

This earthquake released about 340 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 500× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 22× the energy of this one
  3. Magna, Utah 2020 M 5.7 16× the energy of this one
  4. This earthquake M 4.9 about 340 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 710× more

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

The largest earthquake within 50 km since 2016 was M 6.9 on 2018-05-04 — about 1,000 times the energy of this one.

Before 2016, the USGS record lists 43 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.7 17 km SSW of Leilani Estates, Hawaii · 30 km ESE of this epicentre
  2. 6.7 Island of Hawai`i, Hawaii · 28 km ESE of this epicentre
  3. 6.7 22 km W of Volcano, Hawaii · 18 km W of this epicentre
  4. 6.4 Kaoiki area, Hawaii · 13 km WNW of this epicentre
  5. 6.2 Kilauea South Flank, Hawaii · 28 km ESE 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 19.4050, -155.2810. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hawaii County, HI 32 km (20 mi) NW earthquakes near Hawaii County

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

Aftershocks so far

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

  1. 2.7 13 km SSE of Volcano, Hawaii
  2. 2.9 10 km SW of Volcano, Hawaii
  3. 2.9 6 km SW of Volcano, Hawaii
  4. 2.6 5 km SW of Volcano, Hawaii
  5. 2.3 10 km SSW of Leilani Estates, Hawaii
  6. 1.7 11 km SSW of Leilani Estates, Hawaii
  7. 1.6 9 km SSW of Volcano, Hawaii
  8. 2.6 14 km SSE of Volcano, Hawaii
  9. 3.7 13 km SSE of Volcano, Hawaii
  10. 2.4 3 km WSW of Volcano, Hawaii
  11. 2.0 6 km SW of Volcano, Hawaii
  12. 2.6 11 km W of Volcano, Hawaii
  13. 2.4 6 km SW of Volcano, Hawaii
  14. 2.0 3 km SSW of Leilani Estates, Hawaii
  15. 2.2 15 km SSE of Fern Forest, Hawaii

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.