A shallow and significant M5.1 earthquake struck in the North Atlantic Ocean 57 kilometer from Ponta Delgada, Portugal in the evening of Tuesday October 20th, 2026.
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Earthquake Summary
This earthquake hit under water in the North Atlantic Ocean, 1867 kilometers (1160 mi) off the coast of Portugal, 57 kilometer northwest of Ponta Delgada in Azores. 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: | Oct 20, 2026 18:07 (Azores Time) - Oct 20, 2026 18:07 Universal Time. |
|---|---|
| Location: | 57 km NW of Ponta Delgada, Azores, Portugal. Coordinates 37°57'27"N 26°15'32"W. |
| Map: |  Map of area around epicenter. Click to open in Google Maps. |
| Magnitude: | MAG 5.1 Detected by 20 stations. Maximum Error Range ±0.069 . |
| 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
The closest significant population center near the earthquake is Ponta Delgada in Azores, Portugal. Ponta Delgada is located 57 kilometer (35 mi) northwest of the epicenter.
Overview of nearby places
| Distance | Place |
|---|---|
| 57 km (35 mi) SE from epicenter |
Ponta Delgada Azores, Portugal. |
Shaking reported by 8 people
People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 8 people have reported shaking in 4 places, all within Portugal.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.
Places with most reports:
- Arrifes, Açores, Portugal: 3 people.
- Rosto do Cão, Açores, Portugal: 2 people.
- Vila Franca do Campo, Açores, Portugal: 2 people.
- Ponta Delgada, Açores, Portugal: 1 person.
7 Aftershocks detected
Since this main shock, 7 smaller aftershocks were detected. A 5.1 magnitude earthquake hit 2 sec later 81 km (51 mi) east of this earthquake.
Overview of foreshocks and aftershocks
| Classification | Magnitude | When | Where |
|---|---|---|---|
| Main Shock This Earthquake |
M 5.1 |
Oct 20, 2026 18:07 (Azores Time) | - |
| Aftershock | M 5.1 |
2 sec later Oct 20, 2026 18:07 (Azores Time) | 81 km (51 mi) E from Main Shock. |
| Aftershock | M 2.6 |
19 mins later Oct 20, 2026 18:26 (Azores Time) | 18 km (11 mi) S from Main Shock. |
| Aftershock | M 3.4 |
24 mins later Oct 20, 2026 18:30 (Azores Time) | 10 km (6 mi) S from Main Shock. |
| Aftershock | M 2.5 |
38 mins later Oct 20, 2026 18:45 (Azores Time) | 11 km (7 mi) S from Main Shock. |
| Aftershock | M 2.5 |
43 mins later Oct 20, 2026 18:49 (Azores Time) | 7 km (4 mi) S from Main Shock. |
| Aftershock | M 2.5 |
52 mins later Oct 20, 2026 18:59 (Azores Time) | 10 km (6 mi) S from Main Shock. |
| Aftershock | M 3.2 |
1 hr later Oct 20, 2026 19:19 (Azores Time) | 11 km (7 mi) S 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).This is an unusually powerful earthquake
Earthquakes of this strength are not so common in the region, but it's not the first time. This is the strongest earthquake to hit since August 2nd, 2025, when a 5.2 magnitude earthquake hit 223 km (138 mi) further east. An even stronger magnitude 5.4 earthquake struck on January 11th, 2021.
In total, 2 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 5 years.
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 20/10/26 22:28 (). This article contains currently available information about the earthquake and is automatically composed. We continue to update this article up to a few days after the earthquake occurred.
- US Geographic Society (USGS): Earthquake us6000u3p1
- Geonames.org: World Cities Database
- Google Maps: Static API
- Earthquakelist.org: Historic Earthquakes Database
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