5.5

M5.5 Earthquake 21 km NW of Kultuk, Russia — September 21, 2020

2020-09-21 18:04:57 UTC (2020-09-21) · approx. 1:04 AM UTC+7 local

Felt by 46 people across nearby locations. Maximum shaking intensity MMI 6.8 (very strong).

MagnitudeM5.5(mww)
Time18:04 UTC≈ 1:04 AM UTC+7
Depth10.0 kmshallow crustal
Coordinates51.857°, 103.480°
Felt by46DYFI responses· max MMI 6.8
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On September 21, 2020 at 18:04 UTC, a magnitude 5.5 shallow crustal earthquake struck 21 km NW of Kultuk, Russia, at a depth of 10.0 km and coordinates 51.8569°, 103.4802°. The earthquake was reported felt by 46 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 6.8 (very strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Kultuk (population 4,151).

Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Russia, a region characterized by the Kuril-Kamchatka subduction zone on the northwestern Pacific Ring of Fire. The nearest mapped fault system is the Kuril-Kamchatka Trench. View all earthquakes in Russia.

Learn more: Magnitude scale · Aftershock sequences

Nearest Populated Places

Kultukpop. 4,151
MMI 4.8 (moderate)
Slyudyankapop. 18,809
MMI 4.5 (moderate)
Shamankapop. 1,700
MMI 4.2 (moderate)
Smolenshchinapop. 2,200
MMI 4.2 (moderate)
Shelekhovpop. 47,459
MMI 4.1 (moderate)
Baklashipop. 3,000
MMI 4.1 (moderate)
Map showing earthquake epicenter at 51.86°, 103.48°

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 M5.5 earthquake near 21 km NW of Kultuk, Russia

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 46 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 M5.5 earthquake near 21 km NW of Kultuk, Russia

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

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak502,818
MMI 4light1,027,020
MMI 5moderate14,854
MMI 6strong1,278

Earthquake Details

Magnitude
5.5 mww
Depth
10.0 km
shallow crustal
Location
51.8569°N
103.4802°E
Felt Reports
46
DYFI responses
Intensity (MMI)
6.8
very strong
Community Intensity
6.8
CDI from reports

Technical Information

Event ID
us6000bzek
Event Type
earthquake
Status
✓ Reviewed
Significance
497
Azimuthal Gap
28.0°
Min Station Distance
0.203°
RMS Residual
0.68 sec
Last Updated
2025-12-22 18:42:37 UTC

Common Questions

How strong was the magnitude 5.5 earthquake near Kultuk, Russia?

The magnitude 5.5 earthquake that struck 21 km NW of Kultuk, Russia on September 21, 2020 at 18:04 UTC had a depth of 10.0 km. It was felt by 46 people with maximum shaking intensity of MMI 6.8 (very strong). For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 51.8569°, 103.4802°, which is 21 km NW of Kultuk, Russia. The nearest populated place is Kultuk (population 4,151). View all earthquakes in Russia.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.

Has Russia had earthquakes this big before?

The largest recorded earthquake in Russia was the M9.0 Kamchatka earthquake of November 4, 1952. Today's magnitude 5.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000bzek). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, September 21, 2020). M5.5 Earthquake 21 km NW of Kultuk, Russia — September 21, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000bzek/