M4.7 Earthquake 70 km SE of Kirakira, Solomon Islands — October 18, 2021
2021-10-18 22:43:24 UTC (2021-10-18) · approx. 9:43 AM UTC+11 local
Aftershock of the M5.6 mainshock.
On October 18, 2021 at 22:43 UTC, a magnitude 4.7 shallow crustal earthquake struck 70 km SE of Kirakira, Solomon Islands, at a depth of 40.5 km and coordinates -10.9823°, 162.2775°.
Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 169 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — 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 5.6 mainshock that occurred 13 days ago 93 km SE of Kirakira, Solomon Islands. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
162.2775°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.7 earthquake near Kirakira, Solomon Islands?
The magnitude 4.7 earthquake that struck 70 km SE of Kirakira, Solomon Islands on October 18, 2021 at 22:43 UTC had a depth of 40.5 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -10.9823°, 162.2775°, which is 70 km SE of Kirakira, Solomon Islands.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 4.7 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 93 km SE of Kirakira, Solomon Islands. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Authoritative source: USGS event page (event ID: us6000fwqt). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 18, 2021). M4.7 Earthquake 70 km SE of Kirakira, Solomon Islands — October 18, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fwqt/