Significant M5.6 AFTERSHOCK struck on Wednesday Night in the North Pacific Ocean 170km from Hachinohe (Japan).

Written by Earthquakelist.org on April 21st, 2026. Last updated April 22nd, 2026.

A significant Magnitude 5.6 aftershock struck in the North Pacific Ocean 170 kilometer from Hachinohe, Japan deep in the night of Wednesday April 22nd, 2026. Shaking may have been felt by a total of 1.3 million people.

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Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 168 kilometers (105 mi) off the coast of Japan, 170 kilometer east of Hachinohe in Aomori. The center of this earthquake had a quite shallow depth of 35 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Apr 22, 2026 03:44 (Tokyo Time) - Apr 21, 2026 18:44 Universal Time.
Location:	170 km east of Hachinohe, Aomori, Japan. Coordinates 40°9'22"N 143°27'36"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.6 Detected by 20 stations. Maximum Error Range ±0.069 .
Depth:	35 km (22 mi) A quite shallow depth.
Max. Intensity:	IV Light On the Modified Mercalli Scale.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually cause tsunami's. Always stay cautious - More info here.

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 90% likelyhood of between 0 and 1 fatalities.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 90% likelyhood of between 0 and 1 million US Dollars in economic damage and impact.

Roughly 1.3 million people exposed to shaking

An estimated 1.3 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.

Weak shaking and probably no damage may have been experienced by an estimated 920,800 people. At III, it is the highest MMI level this earthquake has caused. All exposure to shaking was within the borders of Japan .

Nearby towns and cities

This earthquake may have been felt in Japan . Miyako in Iwate, Japan is the nearest significant place from the epicenter. The earthquake occurred 141 kilometer (88 mi) north-east of Miyako. Miyako experienced an earthquake intensity (MMI Scale) of roughly III. That level implies weak shaking and probably no damage.

Multiple major population centers exist within 300km of the earthquake that struck today. Morioka is located 203 km to the west (intensity unknown, possibly low). Hachinohe is located 170 km to the west and experienced an intensity of III (weak shaking, probably no damage). Aomori is located 242 km to the west (intensity unknown, possibly low).

A complete list of nearby places is included below. Estimated intensity data (MMI) sourced from a shake-map published by the US Geographic Survey is shown where available (cities without data probably experienced little impact).

Overview of nearby places

Earthquake Intensity Map

The intensity in shaking and damage by this earthquake is illustrated through the map below. The highest intensity measured for this earthquake is III.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

This is likely an aftershock

This earthquake was an aftershock. A larger mag. 7.4 earthquake struck 42 km (26 mi) southwest in advance of this 5.6 earthquake around 1 day earlier.

Overview of foreshocks and aftershocks

More earthquakes coming?

The risk of aftershocks decreases rapidly over time. Usually, aftershocks are at least one order of magnitude lower than a main shock.

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 happen often in the region

Earthquakes of this strength are very common in the region. In total, 42 earthquakes with a magnitude of 5.6 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 months.

Low tsunami risk

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Sources

Last updated 22/04/26 12:18 (). 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 us6000srvu
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260421_0000326
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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