Shallow M5.5 AFTERSHOCK struck on Wednesday Night in the North Pacific Ocean 154km from Hachinohe (Japan).

Written by Earthquakelist.org on April 21st, 2026. Last updated May 17th, 2026.

In the North Pacific Ocean 154 kilometer from Hachinohe, Japan, a shallow and significant Magnitude 5.5 aftershock occurred deep in the night of Wednesday April 22nd, 2026. Around 2.2 million people have been exposed to shaking.

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Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 145 kilometers (90 mi) off the coast of Japan, 154 kilometer east of Hachinohe in Aomori. The center of this earthquake had a very shallow depth of 16 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:	154 km east of Hachinohe, Aomori, Japan. Coordinates 40°8'9"N 143°14'54"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.5 Detected by 33 stations. Maximum Error Range ±0.054 .
Depth:	16 km (10 mi) A very 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 2.2 million people exposed to shaking

The USGS has published a report estimating the number of people exposed to this earthquake. Acoording to their analysis, roughly 2.2 million have been exposed to shaking at an MMI level of II or higher.

The highest earthquake impact level for this earthquake is III, which corresponds with weak shaking and probably no damage. Roughly 1,920,000 people are expected to be exposed to this level. 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 124 kilometer (77 mi) north-east of Miyako. The intensity of shaking and damage in Miyako is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

Multiple major population centers exist within 300km of the earthquake that struck today. Sendai is located 292 km to the southwest (intensity unknown, possibly low). Morioka is located 185 km to the west and experienced an intensity of III (weak shaking, probably no damage). Hachinohe is located 154 km to the west and experienced an intensity of III (weak shaking, probably no damage).

The table below provides an overview of all places in proximity of today's earthquake. Where available, the estimated intensity on the Modified Mercalli Intensity Scale in each place is included. Places where this information is omitted likely experienced little impact.

Overview of nearby places

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is IV. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.

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 27 km (17 mi) southwest in advance of this 5.5 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.

It's always adviced to be cautious of the risk of a larger shock following any significant earthquake, however this risk is fairly small. There is a roughly 94 percent change that no larger main shock will follow in the days following this earthquake.

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. In total, 68 earthquakes with a magnitude of 5.5 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 2 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 17/05/26 21:08 (). 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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