4.2

M4.2 Earthquake 103 km ESE of Iquique, Chile — July 29, 2021

2021-07-29 22:03:05 UTC (2021-07-29) · approx. 5:03 PM UTC-5 local

MagnitudeM4.2(mb)
Time22:03 UTC≈ 5:03 PM UTC-5
Depth100.5 kmintermediate depth
Coordinates-20.488°, -69.204°
Felt by5DYFI responses
Status✓ Reviewed by USGS

On July 29, 2021 at 22:03 UTC, a magnitude 4.2 intermediate depth earthquake struck 103 km ESE of Iquique, Chile, at a depth of 100.5 km and coordinates -20.4885°, -69.2045°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at -20.49°, -69.20°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 5 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.2 earthquake near 103 km ESE of Iquique, Chile

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.2 mb
Depth
100.5 km
intermediate depth
Location
-20.4885°N
-69.2045°E
Felt Reports
5
DYFI responses
Community Intensity
3.3
CDI from reports

Technical Information

Event ID
us6000f0ev
Event Type
earthquake
Status
✓ Reviewed
Significance
273
Azimuthal Gap
65.0°
Min Station Distance
0.348°
RMS Residual
0.80 sec
Last Updated
2021-10-03 05:23:45 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Iquique, Chile?

The magnitude 4.2 earthquake that struck 103 km ESE of Iquique, Chile on July 29, 2021 at 22:03 UTC had a depth of 100.5 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000f0ev). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, July 29, 2021). M4.2 Earthquake 103 km ESE of Iquique, Chile — July 29, 2021. Retrieved October 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f0ev/