Shallow M5.1 AFTERSHOCK struck on Monday Evening in the North Pacific Ocean 186km from Morioka (Japan).

Written by Earthquakelist.org on April 20th, 2026. Last updated May 10th, 2026.

A shallow and significant Magnitude 5.1 aftershock struck in the North Pacific Ocean 186 kilometer from Morioka, Japan in the evening of Monday April 20th, 2026.

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Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 140 kilometers (87 mi) off the coast of Japan, 186 kilometer east of Morioka in Iwate. The center of this earthquake had a very shallow depth of 24 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Apr 20, 2026 21:56 (Tokyo Time) - Apr 20, 2026 12:56 Universal Time.
Location:	186 km east of Morioka, Iwate, Japan. Coordinates 39°38'52"N 143°19'40"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.1 Detected by 363 stations. Maximum Error Range ±0.03 .
Depth:	24 km (15 mi) A very shallow depth.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually cause tsunami's. Always stay cautious - More info here.

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 119 kilometer (74 mi) east of Miyako.

Multiple large cities are in proximity of today's earthquake. Sendai is located 262 km to the southwest. Morioka is located 186 km to the west. Hachinohe is located 182 km to the northwest.

An overview of nearby towns and cities is available in the overview below.

Overview of nearby places

This is likely an aftershock

This earthquake was an aftershock. A larger mag. 7.4 earthquake struck 42 km (26 mi) northwest in advance of this 5.1 earthquake around 5 hrs earlier.

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 happen often in the region

Earthquakes of this strength are very common in the region. In total, 156 earthquakes with a magnitude of 5.1 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 23 days.

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 10/05/26 15:18 (). 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 us6000srjx
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20260420_0000210
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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