On Wednesday Evening a Shallow M5.8 Earthquake struck in the North Pacific Ocean near Dededo Village (Guam).

Written by Earthquakelist.org on May 28th, 2025. Last updated July 19th, 2025.

Just before midnight of Wednesday May 28th, 2025, a shallow and significant MAG-5.8 earthquake hit in the North Pacific Ocean 88 kilometer from Dededo Village, Guam. Around 180 thousand people have been exposed to shaking. Another country near the epicenter is Northern Mariana Islands.

Earthquake Summary

This earthquake hit under water in the North Pacific Ocean, 62 kilometers (38 mi) off the coast of Guam, 88 kilometer south of Dededo Village in Dededo. The center of this earthquake had a quite shallow depth of 28 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	May 28, 2025 23:34 (Guam Time) - May 28, 2025 13:34 Universal Time.
Location:	88 km south of Dededo Village, Dededo, Guam. Coordinates 12°44'5"N 144°57'25"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.8 Detected by 14 stations. Maximum Error Range ±0.063 .
Depth:	28 km (17 mi) A quite shallow depth.
Max. Intensity:	V Moderate 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 180 thousand people exposed to shaking

This earthquake may have been felt by around 180 thousand people. That is the expected population size of the area exposed to a level of shaking of II or higher on the Modified Mercalli scale according to the USGS.

The highest earthquake impact level for this earthquake is V, which corresponds with moderate shaking and very light damage. Roughly 2,670 people are expected to be exposed to this level. Intensity level IV was experienced by the majority of people (around 170 thousand). In their region, light shaking and likely no damage can be expected.

People in 2 countries have been exposed to shaking. In Guam , around 170 thousand people, with impact levels up to V (moderate shaking, very light damage). Shaking was experienced by inhabitants of Northern Mariana Islands too.

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
0	II	Very weak	None
3,190	III	Weak	Probably none
170,900	IV	Light	Likely none
2,670	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

Guam and Northern Mariana Islands are both located within 300km distance of the epicenter of the earthquake.

Located 81 kilometer (50 mi) south-southeast of the epicenter of this earthquake, Mangilao Village (Mangilao, Guam) is the nearest significant population center. Mangilao Village experienced an earthquake intensity (MMI Scale) of roughly IV. That level implies light shaking and likely no damage.

An overview of nearby towns and cities is available in the overview below. If places don't have intensity data available, it likely means the experienced impact in those places was fairly small.

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
81 km (50 mi) NNW from epicenter	Mangilao Village Mangilao, Guam.	IV Light
85 km (53 mi) NNW from epicenter	Hagåtña Hagatna, Guam.	IV Light
85 km (53 mi) NNW from epicenter	Guam Government House Hagatna, Guam.	IV Light
86 km (53 mi) NNW from epicenter	Tamuning Tamuning, Guam.	IV Light
86 km (53 mi) NNW from epicenter	Tamuning-Tumon-Harmon Village Tamuning, Guam.	IV Light
88 km (55 mi) N from epicenter	Dededo Village Dededo, Guam.	IV Light
89 km (55 mi) N from epicenter	Yigo Village Yigo, Guam.	IV Light
289 km (180 mi) NNE from epicenter	Saipan Saipan, Northern Mariana Islands.

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is V. 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.

Aftershocks detected

This main shock was prefaced by 4 smaller foreshocks. Roughly 1 day before this earthquake, a foreshock measuring MAG-5 was detected nearby 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
Foreshock	M 5.0	1 day earlier May 27, 2025 12:57 (Guam Time)	40 km (25 mi) ENE from Main Shock.
Foreshock	M 4.5	1 day earlier May 27, 2025 13:00 (Guam Time)	50 km (31 mi) ENE from Main Shock.
Foreshock	M 4.4	1 day earlier May 27, 2025 15:24 (Guam Time)	54 km (33 mi) ENE from Main Shock.
Foreshock	M 4.5	16 hrs earlier May 28, 2025 07:26 (Guam Time)	41 km (25 mi) NE from Main Shock.
Main Shock This Earthquake	M 5.8	May 28, 2025 23:34 (Guam Time)	-

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.

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 are common in the region

Earthquakes of this strength occur quite regularly in the region. This is the strongest earthquake to hit since August 14th, 2023, when a 6.1 magnitude earthquake hit 287 km (178 mi) further east-northeast. That was also the heaviest earthquake to hit the region in the past 10 years.

In total, 6 earthquakes with a magnitude of 5.8 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 years.

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 5.8. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 28 km (17 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 19/07/25 04:38 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.