6.3

M6.3 Earthquake in the Izu Islands, Japan regionNovember 29, 2021

2021-11-29 12:40:44 UTC (2021-11-29) · approx. 10:40 PM UTC+10 local

Felt by 80 people across nearby locations.

MagnitudeM6.3(mww)
Time12:40 UTC10:40 PM UTC+10
Depth11.0 kmshallow crustal
Coordinates31.196°, 142.503°
Felt by80DYFI responses· max MMI 2.8
Status✓ Reviewed by USGS· Tsunami evaluation· green PAGER
green Alertno significant casualties or damage expected
Tsunami Warning Issued

On November 29, 2021 at 12:40 UTC, a magnitude 6.3 shallow crustal earthquake struck in the Izu Islands, Japan region, at a depth of 11.0 km and coordinates 31.1960°, 142.5026°. The earthquake was reported felt by 80 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.8 (weak). 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 6.3 releases seismic energy equivalent to roughly 43 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 13 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Japan, a region characterized by the intersection of four tectonic plates — Pacific, Philippine Sea, Eurasian, and North American — creating multiple subduction zones. The nearest mapped fault system is the Japan Trench. View all earthquakes in Japan.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 31.20°, 142.50°

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 M6.3 earthquake near Izu Islands, Japan region

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 80 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 M6.3 earthquake near Izu Islands, Japan region

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 3weak14,296

Earthquake Details

Magnitude
6.3 mww
Depth
11.0 km
shallow crustal
Location
31.1960°N
142.5026°E
Felt Reports
80
DYFI responses
Intensity (MMI)
2.8
weak
Community Intensity
5.8
CDI from reports

Technical Information

Event ID
us7000fxyq
Event Type
earthquake
Status
✓ Reviewed
Significance
657
Azimuthal Gap
35.0°
Min Station Distance
2.976°
RMS Residual
0.75 sec
Last Updated
2025-12-22 22:21:03 UTC

Common Questions

How strong was the magnitude 6.3 earthquake in the Izu Islands, Japan region?

The magnitude 6.3 earthquake that struck in the Izu Islands, Japan region on November 29, 2021 at 12:40 UTC had a depth of 11.0 km. It was felt by 80 people with maximum shaking intensity of MMI 2.8 (weak). For context, this was a strong earthquake capable of causing significant damage.

Where did the earthquake occur?

The earthquake epicenter was located at 31.1960°, 142.5026°, which is in the Izu Islands, Japan region. View all earthquakes in Japan.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.3 earthquakes can continue for weeks to months and gradually diminish over time.

Has Japan had earthquakes this big before?

The largest recorded earthquake in Japan was the M9.1 Tohoku earthquake of March 11, 2011. Today's magnitude 6.3 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000fxyq). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, November 29, 2021). M6.3 Earthquake in the Izu Islands, Japan regionNovember 29, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000fxyq/