A shallow and significant Magnitude 5.1 aftershock struck in the North Pacific Ocean 200 kilometer from Nemuro, Japan in the early afternoon of Sunday December 21st, 2025.
Felt the earthquake? Share this article: 
Earthquake Summary
This earthquake hit under water in the North Pacific Ocean, 248 kilometers (154 mi) off the coast of Japan, 200 kilometer east of Nemuro in Hokkaido. The center of this earthquake had a very shallow depth of 10 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.
| Date and Time: | Dec 21, 2025 13:03 (Tokyo Time) - Dec 21, 2025 04:03 Universal Time. |
|---|---|
| Location: | 200 km east of Nemuro, Hokkaido, Japan. Coordinates 43°25'47"N 148°2'26"E. |
| Map: |  Map of area around epicenter. Click to open in Google Maps. |
| Magnitude: | MAG 5.1 Detected by 115 stations. Maximum Error Range ±0.053 . |
| Depth: | 10 km (6 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 . Nemuro in Hokkaido, Japan is the nearest significant place from the epicenter. The earthquake occurred 200 kilometer (124 mi) east of Nemuro.
Overview of nearby places
| Distance | Place |
|---|---|
| 200 km (124 mi) W from epicenter |
Nemuro Hokkaido, Japan. |
| 236 km (147 mi) W from epicenter |
Shibetsu Hokkaido, Japan. |
| 248 km (154 mi) W from epicenter |
Nakashibetsu Hokkaido, Japan. |
This is likely an aftershock
Approximately 16 mins before this earthquake hit, a larger 5.2 magnitude earthquake struck 4 km (2.4 mi) northwest of this one. For that reason, we classify the Mag. 5.1 earthquake as an aftershock.
Overview of foreshocks and aftershocks
| Classification | Magnitude | When | Where |
|---|---|---|---|
| Foreshock | M 4.4 |
3 days earlier Dec 18, 2025 18:54 (Tokyo Time) | 24 km (15 mi) SSE from Main Shock. |
| Foreshock | M 5.0 |
3 days earlier Dec 18, 2025 23:42 (Tokyo Time) | 5 km (3 mi) SW from Main Shock. |
| Foreshock | M 4.4 |
2 days earlier Dec 19, 2025 01:56 (Tokyo Time) | 25 km (16 mi) NNW from Main Shock. |
| Foreshock | M 4.5 |
2 days earlier Dec 19, 2025 10:25 (Tokyo Time) | 23 km (14 mi) SSW from Main Shock. |
| Foreshock | M 4.4 |
2 days earlier Dec 19, 2025 13:30 (Tokyo Time) | 8 km (5 mi) NW from Main Shock. |
| Foreshock | M 4.8 |
4 hrs earlier Dec 21, 2025 08:46 (Tokyo Time) | 5 km (2.9 mi) SSW from Main Shock. |
| Foreshock | M 4.8 |
4 hrs earlier Dec 21, 2025 08:46 (Tokyo Time) | 58 km (36 mi) NNW from Main Shock. |
| Foreshock | M 5.0 |
3 hrs earlier Dec 21, 2025 09:19 (Tokyo Time) | 16 km (10 mi) S from Main Shock. |
| Foreshock | M 5.0 |
3 hrs earlier Dec 21, 2025 09:22 (Tokyo Time) | 25 km (15 mi) NW from Main Shock. |
| Foreshock | M 4.9 |
3 hrs earlier Dec 21, 2025 09:26 (Tokyo Time) | 28 km (18 mi) NNW from Main Shock. |
| Foreshock | M 5.1 |
2 hrs earlier Dec 21, 2025 11:05 (Tokyo Time) | 61 km (38 mi) NW from Main Shock. |
| Foreshock | M 4.7 |
14 mins earlier Dec 21, 2025 12:33 (Tokyo Time) | 66 km (41 mi) NW from Main Shock. |
| Main Shock | M 5.2 |
Dec 21, 2025 12:48 (Tokyo Time) | - |
| Aftershock | M 5.0 |
5 mins later Dec 21, 2025 12:52 (Tokyo Time) | 16 km (10 mi) W from Main Shock. |
| Aftershock This Earthquake |
M 5.1 |
16 mins later Dec 21, 2025 13:03 (Tokyo Time) | 4 km (2.4 mi) SE from Main Shock. |
| Aftershock | M 4.7 |
59 mins later Dec 21, 2025 13:47 (Tokyo Time) | 34 km (21 mi) NW from Main Shock. |
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
Read: How to Stay Safe during an Earthquake (cdc.gov).Earthquakes like this happen often in the region
Earthquakes of this strength are very common in the region. In total, 54 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 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
| Factor | Under Sea? | MAG-6.5 or stronger? | Shallow depth? |
|---|---|---|---|
| Explanation | Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami. | Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's. |
Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor. |
| This Earthquake | This earthquake appears to have struck under the sea. | Not this earthquake. This earthquake had a magnitude of 5.1. Earthquakes of this strength are unlikely to trigger a tsunami. |
This earthquake occurred at a depth of of 10 km (6 mi). Earthquakes this shallow could trigger a tsunami. |
Sources
Last updated 07/01/26 06:18 (). 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.
- US Geographic Society (USGS): Earthquake us6000rwa4
- European-Mediterranean Seismological Centre (EMSC): Earthquake 20251221_0000068
- Geonames.org: World Cities Database
- Google Maps: Static API
- Earthquakelist.org: Historic Earthquakes Database
Share this article:
