QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Emajagua, PR

No earthquake was likely felt in Emajagua in the 24 hours to 4:29 pm AST (20:29 UTC). The last one was M 2.2, 7 km (5 mi) ESE, at 2:59 pm AST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Emajagua

This page: a magnitude 1.9 earthquake was recorded 7 km (4 mi) south-southwest of Emajagua, PR, at 8:58 am AST on 23 July 2018 (12:58 UTC), 12 km deep.

USGS: 6 km SSW of Emajagua, Puerto Rico

54 km (33 mi) SSE of San Juan, PR · 35 km (22 mi) SSE of Caguas, PR

8:58 am AST, Jul 23, 2018 · · 12 km deep · released about 21 lb of TNT

Every earthquake near Emajagua Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Maunabo Municipio 6 kmPatillas Municipio 10 kmYabucoa Municipio 14 kmArroyo Municipio 15 kmSan Lorenzo Municipio 23 kmGuayama Municipio 25 kmHumacao Municipio 25 kmLas Piedras Municipio 27 kmJuncos Municipio 31 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
8:58 am AST on 23 July 2018 ()
Where
7 km (4 mi) south-southwest of Emajagua, PR · earthquakes near Emajagua
Magnitude
M 1.9 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Maunabo Municipio, 6 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3033 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Emajagua, 7 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: Emajagua 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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

The largest earthquake within 50 km since 2016 was M 4.6 on 2016-12-05 — about 12,000 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 42 km NW 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 17.9463, -65.9070. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Maunabo Municipio, PR 6 km (4 mi) N earthquakes near Maunabo Municipio
Patillas Municipio, PR 10 km (6 mi) NW earthquakes near Patillas Municipio
Yabucoa Municipio, PR 14 km (8 mi) NNE earthquakes near Yabucoa Municipio
Arroyo Municipio, PR 15 km (9 mi) WNW earthquakes near Arroyo Municipio
San Lorenzo Municipio, PR 23 km (15 mi) NNW earthquakes near San Lorenzo Municipio
Guayama Municipio, PR 25 km (15 mi) W earthquakes near Guayama Municipio

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. 2.1 3 km SSW of Salinas, Puerto Rico
  2. 1.7 2 km S of Jauca, Puerto Rico
  3. 2.2 2 km SE of Cidra, Puerto Rico
  4. 2.2 22 km SSE of Lamboglia, Puerto Rico
  5. 2.6 3 km NNW of Benitez, Puerto Rico
  6. 2.6 14 km SW of Esperanza, Puerto Rico
  7. 1.6 2 km SE of Cayey, Puerto Rico
  8. 1.6 4 km WNW of Yaurel, Puerto Rico
  9. 1.6 2 km E of Bayamon, Puerto Rico
  10. 2.2 5 km ESE of G. L. Garcia, Puerto Rico
  11. 2.1 2 km SSW of Aguas Buenas, Puerto Rico
  12. 2.0 18 km SE of El Negro, Puerto Rico
  13. 2.0 1 km SSW of Jauca, Puerto Rico
  14. 2.4 21 km SE of El Negro, Puerto Rico
  15. 2.3 6 km NW of Yaurel, Puerto Rico

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.