Shallow M6.6 AFTERSHOCK struck on Tuesday Morning in the North Pacific Ocean 151km from Hachinohe (Japan).

Written by Earthquakelist.org on December 8th, 2025. Last updated December 10th, 2025.

In the North Pacific Ocean 151 kilometer from Hachinohe, Japan, a shallow and strong Magnitude 6.6 aftershock occurred in the early morning of Tuesday December 9th, 2025. Mag 6.5+ earthquakes at shallow depth under sea have the potential to cause tsunami's.

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Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 103 kilometers (64 mi) off the coast of Japan, 151 kilometer east-northeast of Hachinohe in Aomori. The center of this earthquake had a very shallow depth of 19 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Dec 9, 2025 06:52 (Tokyo Time) - Dec 8, 2025 21:52 Universal Time.
Location:	151 km ENE of Hachinohe, Aomori, Japan. Coordinates 41°0'12"N 143°9'49"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 6.6 Detected by 21 stations. Maximum Error Range ±0.068 .
Depth:	19 km (12 mi) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Potential Tsunami Risk Mag 6.5+ earthquakes at shallow depth under sea have the potential to cause tsunami's. Always stay cautious - More info here.

Potential Tsunami Risk

There is a potential tsunami risk in the aftermath of this earthquake, immediately evacuate to higher grounds away from coastal areas and monitor advice from local authorities. This earthquake checks all the likely tsunami risk factors: under sea, at a magnitude of MAG-6.5+ and at a shallow depth.

Tsunami Risk Factors

Minimal impact predicted

Based on scientific estimates by the US Geographic Survey (USGS), the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls no higher than 10 million USD.

Roughly 1.9 million people exposed to shaking

An estimated 1.9 million have been exposed to shaking (An MMI or Modified Mercalli Intensity level II or higher) as a result of this earthquake according scientific estimates published by the USGS.

An estimated 1,274,000 people were exposed to level IV. At this level, light shaking and likely no damage can be expected. All exposure to shaking was within the borders of Japan .

Nearby towns and cities

This earthquake may have been felt in Japan . The closest significant population center near the earthquake is Hachinohe in Aomori, Japan. Hachinohe is located 151 kilometer (94 mi) east-northeast of the epicenter. The intensity of shaking and damage in Hachinohe is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Multiple major population centers exist within 300km of the earthquake that struck today. Sapporo is located 274 km to the northwest (intensity unknown, possibly low). Sendai is located 362 km to the south-southwest (intensity unknown, possibly low). Niigata is located 497 km to the southwest (intensity unknown, possibly low).

An overview of nearby towns and cities is available in the overview below. If places don't have intensity data available, it likely means the experienced impact in those places was fairly small.

Overview of nearby places

Earthquake Intensity Map

The graph below overlays a map of the region around the epicenter with earthquake intensity data provided by the US Geographic Survey. The highest intensity level detected for this earthquake is V.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

Shaking reported by 3 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 3 people have reported shaking in 3 places, all within Japan.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

• Hachinohe, Aomori, Japan: 1 person.
• Iwanai, Hokkaido, Japan: 1 person.
• Hamamatsu, Shizuoka, Japan: 1 person.

This is likely an aftershock

Approximately 8 hrs before this earthquake hit, a larger 7.6 magnitude earthquake struck 86 km (53 mi) west of this one. For that reason, we classify the Mag. 6.6 earthquake as an aftershock.

Overview of foreshocks and aftershocks

More earthquakes coming?

Aftershocks are usually at least 1 order of magnitude less strong than main shocks. The more time passes, the smaller the chance and likely strength of any potential aftershocks.

The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk

Earthquakes like this are common in the region

Earthquakes of this strength occur quite regularly in the region. In total, 3 earthquakes with a magnitude of 6.6 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every 3 years.

Sources

Last updated 10/12/25 04:18 (). This article is automatically generated based on available data. We keep checking multiple sources for additional information. This article gets updated as new details on this earthquake become available.

1. US Geographic Society (USGS): Earthquake us6000rtie
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20251208_0000384
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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