4.8

M4.8 Earthquake 168 km SW of Grindavík, Iceland — August 1, 2021

2021-08-01 00:51:11 UTC (2021-08-01) · approx. 10:51 PM UTC-2 local

MagnitudeM4.8(mb)
Time00:51 UTC≈ 10:51 PM UTC-2
Depth10.0 kmshallow crustal
Coordinates62.904°, -25.087°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 1, 2021 at 00:51 UTC, a magnitude 4.8 shallow crustal earthquake struck 168 km SW of Grindavík, Iceland, at a depth of 10.0 km and coordinates 62.9038°, -25.0871°.

Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Iceland, a region characterized by the Mid-Atlantic Ridge, where the North American and Eurasian plates diverge at 18-25 mm per year, amplified by the Iceland mantle plume. The nearest mapped fault system is the Mid-Atlantic Ridge. View all earthquakes in Iceland.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 62.90°, -25.09°

Earthquake Details

Magnitude
4.8 mb
Depth
10.0 km
shallow crustal
Location
62.9038°N
-25.0871°E

Technical Information

Event ID
us6000f140
Event Type
earthquake
Status
✓ Reviewed
Significance
354
Azimuthal Gap
32.0°
Min Station Distance
2.490°
RMS Residual
0.53 sec
Last Updated
2021-10-14 01:04:38 UTC

Common Questions

How strong was the magnitude 4.8 earthquake near Grindavík, Iceland?

The magnitude 4.8 earthquake that struck 168 km SW of Grindavík, Iceland on August 1, 2021 at 00:51 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 62.9038°, -25.0871°, which is 168 km SW of Grindavík, Iceland. View all earthquakes in Iceland.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 earthquakes can continue for several days and gradually diminish over time.

Has Iceland had earthquakes this big before?

The largest recorded earthquake in Iceland was the M6.6 South Iceland earthquake of June 17, 2000. Today's magnitude 4.8 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000f140). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 1, 2021). M4.8 Earthquake 168 km SW of Grindavík, Iceland — August 1, 2021. Retrieved October 14, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f140/