Shallow M5.4 Earthquake hit in the Ionian Sea 164km from Pátra (Greece) on Tuesday Night.

Written by Earthquakelist.org on December 15th, 2025. Last updated January 8th, 2026.

A shallow and significant M5.4 earthquake struck in the Ionian Sea 164 kilometer from Pátra, Greece in the night of Tuesday December 16th, 2025. Around 1.2 million people have been exposed to shaking. Albania is also near its epicenter.

Earthquake Summary

This earthquake hit under water in the Ionian Sea, 66 kilometers (41 mi) off the coast of Greece, 164 kilometer southwest of Pátra in West Greece. The center of this earthquake had a very shallow depth of 15 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Dec 16, 2025 01:41 (Athens Time) - Dec 15, 2025 23:41 Universal Time.
Location:	164 km SW of Pátra, West Greece, Greece. Coordinates 37°25'60"N 20°10'29"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.4 Detected by 33 stations. Maximum Error Range ±0.054 .
Depth:	15 km (9 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 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls no higher than 10 million USD.

Roughly 1.2 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 1.2 million have been exposed to shaking at an MMI level of II or higher.

An estimated 4,870 people were exposed to level IV. At this level, light shaking and likely no damage can be expected. The majority of people (roughly 0.8 million) live in an area exposed to level III, where weak shaking and probably no damage is expected. All exposure to shaking was within the borders of Greece .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
389,100	II	Very weak	None
826,700	III	Weak	Probably none
4,870	IV	Light	Likely none
0	V	Moderate	Very light
0	VI	Strong	Light
0	VII	Very Strong	Moderate
0	VIII	Severe	Moderate to heavy
0	IX	Violent	Heavy
0	X	Extreme	Very heavy

Nearby towns and cities

Greece and Albania are both located within 300km distance of the epicenter of the earthquake.

Located 111 kilometer (69 mi) west-southwest of the epicenter of this earthquake, Amaliáda (West Greece, Greece) is the nearest significant population center. The intensity of shaking and damage in Amaliáda is estimated to be around level III on the Modified Mercalli Intensity scale (weak shaking, probably no damage).

A complete list of nearby places is included below. Estimated intensity data (MMI) sourced from a shake-map published by the US Geographic Survey is shown where available (cities without data probably experienced little impact).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
111 km (69 mi) ENE from epicenter	Amaliáda West Greece, Greece.	III Weak
115 km (71 mi) ENE from epicenter	Pýrgos West Greece, Greece.	III Weak
164 km (102 mi) NE from epicenter	Pátra West Greece, Greece.	III Weak
171 km (106 mi) NE from epicenter	Agrínio West Greece, Greece.	III Weak
177 km (110 mi) ESE from epicenter	Kalamata Peloponnese, Greece.	III Weak
177 km (110 mi) NNE from epicenter	Préveza Epirus, Greece.	III Weak
190 km (118 mi) ENE from epicenter	Aígio West Greece, Greece.	II Weak
195 km (121 mi) E from epicenter	Trípoli Peloponnese, Greece.	III Weak
204 km (127 mi) E from epicenter	Sparta Peloponnese, Greece.	III Weak
205 km (127 mi) NNE from epicenter	Árta Epirus, Greece.	III Weak
227 km (141 mi) E from epicenter	Árgos Peloponnese, Greece.
245 km (152 mi) N from epicenter	Corfu Ionian Islands, Greece.
251 km (156 mi) ENE from epicenter	Kórinthos Peloponnese, Greece.
255 km (158 mi) NNE from epicenter	Ioánnina Epirus, Greece.
256 km (159 mi) NE from epicenter	Lamía Central Greece, Greece.	II Weak
262 km (163 mi) ENE from epicenter	Livadeiá Central Greece, Greece.
263 km (163 mi) NE from epicenter	Kardítsa Thessaly, Greece.
272 km (169 mi) N from epicenter	Sarandë Vlorë, Albania.
274 km (170 mi) NNE from epicenter	Tríkala Thessaly, Greece.
286 km (178 mi) ENE from epicenter	Mégara Attica, Greece.
293 km (182 mi) ENE from epicenter	Thívai Central Greece, Greece.
294 km (183 mi) N from epicenter	Gjirokastër Gjirokastër, Albania.
298 km (185 mi) ENE from epicenter	Salamína Attica, Greece.

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

Earthquake Intensity Map based on Shakemap Data provided by USGS.

Shaking reported by 1 person

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 1 person has reported shaking in one place in Greece.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Messíni, Messinía, Greece: 1 person.

9 Aftershocks detected

Since this main shock, 9 smaller aftershocks were detected. Just 12 hrs after this main shock, an earthquake measuring MAG-3.6 was detected 7 km (4 mi) south-east of this earthquake.

Overview of foreshocks and aftershocks

Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.
Classification	Magnitude	When	Where
Main Shock This Earthquake	M 5.4	Dec 16, 2025 01:41 (Athens Time)	-
Aftershock	M 2.5	6 mins later Dec 16, 2025 01:48 (Athens Time)	22 km (14 mi) NE from Main Shock.
Aftershock	M 3.3	9 mins later Dec 16, 2025 01:51 (Athens Time)	8 km (5 mi) NE from Main Shock.
Aftershock	M 3.2	1 hr later Dec 16, 2025 02:50 (Athens Time)	7 km (4 mi) SSW from Main Shock.
Aftershock	M 2.9	2 hrs later Dec 16, 2025 03:38 (Athens Time)	15 km (10 mi) SW from Main Shock.
Aftershock	M 3.6	12 hrs later Dec 16, 2025 13:56 (Athens Time)	7 km (4 mi) SE from Main Shock.
Aftershock	M 2.6	23 hrs later Dec 17, 2025 01:10 (Athens Time)	7 km (4 mi) N from Main Shock.
Aftershock	M 2.6	1 day later Dec 17, 2025 04:42 (Athens Time)	83 km (52 mi) ESE from Main Shock.
Aftershock	M 2.8	2 days later Dec 18, 2025 06:17 (Athens Time)	97 km (60 mi) NNE from Main Shock.
Aftershock	M 2.6	2 days later Dec 18, 2025 12:27 (Athens Time)	30 km (18 mi) E from Main Shock.

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

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 March 29th, 2024, when a 5.8 magnitude earthquake hit 96 km (60 mi) further east. An even stronger magnitude 6.8 earthquake struck on October 25th, 2018.

In total, 13 earthquakes with a magnitude of 5.4 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 9 months.

Low tsunami risk

DISCLAIMER: We strongly suggest to closely monitor advice from local authorities with regards to tsunami risks. Our analysis is based on automatically collected data from external sources, and these might contain mistakes. In addition, earthquakes can cause landslides that may lead to a tsunami, or be a followed by another, potentially stonger, earthquake.

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 5.4. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 15 km (9 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 08/01/26 00:58 (). 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.