A significant MAG-5.1 foreshock struck in the North Pacific Ocean 162 kilometer from Nemuro, Japan in the morning of Sunday December 21st, 2025.
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Earthquake Summary
This earthquake hit under water in the North Pacific Ocean, 191 kilometers (119 mi) off the coast of Japan, 162 kilometer east-northeast of Nemuro in Hokkaido. 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: | Dec 21, 2025 11:05 (Tokyo Time) - Dec 21, 2025 02:05 Universal Time. |
|---|---|
| Location: | 162 km ENE of Nemuro, Hokkaido, Japan. Coordinates 43°50'14"N 147°27'48"E. |
| Map: |  Map of area around epicenter. Click to open in Google Maps. |
| Magnitude: | MAG 5.1 Detected by 94 stations. Maximum Error Range ±0.059 . |
| Depth: | 35 km (21 mi) A quite 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 . Located 162 kilometer (101 mi) east-northeast of the epicenter of this earthquake, Nemuro (Hokkaido, Japan) is the nearest significant population center.
A complete list of nearby places is included below.
Overview of nearby places
| Distance | Place |
|---|---|
| 162 km (101 mi) WSW from epicenter |
Nemuro Hokkaido, Japan. |
| 188 km (117 mi) W from epicenter |
Shibetsu Hokkaido, Japan. |
| 203 km (126 mi) W from epicenter |
Nakashibetsu Hokkaido, Japan. |
| 257 km (160 mi) W from epicenter |
Abashiri Hokkaido, Japan. |
| 267 km (166 mi) WSW from epicenter |
Kushiro Hokkaido, Japan. |
| 270 km (168 mi) W from epicenter |
Motomachi Hokkaido, Japan. |
| 287 km (178 mi) W from epicenter |
Kitami Hokkaido, Japan. |
This is likely a foreshock
This earthquake was followed by a stronger MAG-5.2 earthquake, classifying this earthquake as a foreshock.
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 This Earthquake |
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 | 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.
In only six percent of cases, significant earthquakes are followed by a larger main shock, making the current earthquake a foreshock. While the chance of this happening is not so large, it is adviced to maintain cautiousness in the hours and days following a major earthquake.
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. This is the strongest earthquake to hit since December 20th, 2025, when a 5.2 magnitude earthquake hit 172 km (107 mi) further southwest. An even stronger magnitude 7 earthquake struck on February 13th, 2020.
In total, 55 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 35 km (21 mi). Earthquakes this shallow could trigger a tsunami. |
Sources
Last updated 08/01/26 04:28 (). 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 us6000rw9k
- European-Mediterranean Seismological Centre (EMSC): Earthquake 20251221_0000037
- Geonames.org: World Cities Database
- Google Maps: Static API
- Earthquakelist.org: Historic Earthquakes Database
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