5.6

M5.6 Earthquake near Sea of OkhotskOctober 9, 2021

2021-10-09 07:19:27 UTC (2021-10-09) · approx. 5:19 PM UTC+10 local

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MagnitudeM5.6(mww)
Time07:19 UTC5:19 PM UTC+10
Depth447.5 kmdeep-focus
Coordinates50.042°, 149.875°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alertno significant casualties or damage expected

On October 9, 2021 at 07:19 UTC, a magnitude 5.6 deep-focus earthquake struck near Sea of Okhotsk, at a depth of 447.5 km and coordinates 50.0419°, 149.8754°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.

Physical scale: An earthquake of magnitude 5.6 releases seismic energy equivalent to roughly 4 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 4.4 km — a useful intuition for the size of the slip patch on the fault.

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Map showing earthquake epicenter at 50.04°, 149.88°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M5.6 earthquake near Sea of Okhotsk

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
5.6 mww
Depth
447.5 km
deep-focus
Location
50.0419°N
149.8754°E
Intensity (MMI)
0.0
weak

Technical Information

Event ID
us6000ft86
Event Type
earthquake
Status
✓ Reviewed
Significance
482
Azimuthal Gap
50.0°
Min Station Distance
5.645°
RMS Residual
0.72 sec
Last Updated
2025-12-22 22:17:35 UTC

Common Questions

How strong was the magnitude 5.6 earthquake near Sea of Okhotsk?

The magnitude 5.6 earthquake that struck near Sea of Okhotsk on October 9, 2021 at 07:19 UTC had a depth of 447.5 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 50.0419°, 149.8754°, which is near Sea of Okhotsk.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.6 earthquakes can continue for days to weeks and gradually diminish over time.

Authoritative source: USGS event page (event ID: us6000ft86). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 9, 2021). M5.6 Earthquake near Sea of OkhotskOctober 9, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000ft86/