4.1

M4.1 Earthquake in the Flores region, IndonesiaOctober 4, 2022

2022-10-04 18:28:03 UTC (2022-10-04) · approx. 2:28 AM UTC+8 local

MagnitudeM4.1(mb)
Time18:28 UTC2:28 AM UTC+8
Depth9.1 kmshallow crustal
Coordinates-8.137°, 120.630°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 4, 2022 at 18:28 UTC, a magnitude 4.1 shallow crustal earthquake struck in the Flores region, Indonesia, at a depth of 9.1 km and coordinates -8.1368°, 120.6297°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 2 hours ago 51 km NNE of Ruteng, Indonesia. Since the mainshock, the USGS has recorded 55 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at -8.14°, 120.63°

Earthquake Details

Magnitude
4.1 mb
Depth
9.1 km
shallow crustal
Location
-8.1368°N
120.6297°E

Technical Information

Event ID
us6000ish6
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
16
Azimuthal Gap
90.0°
Min Station Distance
1.666°
RMS Residual
1.30 sec
Last Updated
2022-12-10 22:54:00 UTC

Common Questions

How strong was the magnitude 4.1 earthquake in the Flores region, Indonesia?

The magnitude 4.1 earthquake that struck in the Flores region, Indonesia on October 4, 2022 at 18:28 UTC had a depth of 9.1 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 4.1 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.3 one earlier?

No. This magnitude 4.1 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 51 km NNE of Ruteng, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000ish6). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, October 4, 2022). M4.1 Earthquake in the Flores region, IndonesiaOctober 4, 2022. Retrieved December 10, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000ish6/