4.2

M4.2 Earthquake near Molucca Sea — January 20, 2023

2023-01-20 19:57:43 UTC (2023-01-20) · approx. 3:57 AM UTC+8 local

MagnitudeM4.2(mb)
Time19:57 UTC≈ 3:57 AM UTC+8
Depth40.8 kmshallow crustal
Coordinates2.637°, 126.754°
Felt byNo felt reports
Status✓ Reviewed by USGS

On January 20, 2023 at 19:57 UTC, a magnitude 4.2 shallow crustal earthquake struck near Molucca Sea, at a depth of 40.8 km and coordinates 2.6372°, 126.7544°.

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.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 17 days ago 161 km WNW of Tobelo, Indonesia. Since the mainshock, the USGS has recorded 1 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 2.64°, 126.75°

Earthquake Details

Magnitude
4.2 mb
Depth
40.8 km
shallow crustal
Location
2.6372°N
126.7544°E

Technical Information

Event ID
us6000jjpk
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Stations Used
24
Azimuthal Gap
111.0°
Min Station Distance
1.951°
RMS Residual
0.69 sec
Last Updated
2023-03-31 19:43:46 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near Molucca Sea?

The magnitude 4.2 earthquake that struck near Molucca Sea on January 20, 2023 at 19:57 UTC had a depth of 40.8 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.

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

No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier 161 km WNW of Tobelo, Indonesia. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

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: us6000jjpk). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, January 20, 2023). M4.2 Earthquake near Molucca Sea — January 20, 2023. Retrieved March 31, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000jjpk/