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M4.2 Earthquake near San Alejandro, Peru — 18 March 2025

A light earthquake of magnitude 4.2 was recorded near San Alejandro, Peru on , with an epicentre 68 km west-northwest of San Alejandro, at a focal depth of 108.9 km. It ranked as the 19th strongest of 20 earthquakes recorded in Peru in the preceding 30 days.

4.2 Light

Time (UTC): 2025-03-18 10:50:37

Time (your timezone): —

Magnitude: 4.2 (light)

Focal depth: 108.9 km (intermediate)

Epicentre: -8.6587, -75.8152

Location: 68 km WNW of San Alejandro, Peru

Country: Peru

USGS link to NOAA tsunami information: Not linked

Review status: Reviewed

Source: USGS event page

How strong was this earthquake?

Light earthquakes are widely felt near the epicentre and can rattle windows, dishes and hanging objects. Damage is uncommon and usually limited to cracked plaster or fallen loose items.

A magnitude 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 271, which is below the USGS threshold of more than 600 for its significant-earthquake list. The ranking combines magnitude with available Did You Feel It responses and PAGER alert level; it is not a direct measurement of damage.

What the magnitude scale actually measures →

When it happened locally

That is about 05:47 local solar time at the epicentre, around dawn.

This event was deeper than 64% of the 277 earthquakes recorded in Peru in our catalogue and stronger than 16% of them.

Where was the epicentre?

The epicentre was located at -8.6587, -75.8152 — 68 km west-northwest of San Alejandro. The closest other recorded event was a magnitude 5.2 earthquake 11 km north-northeast of here on 03 August 2026.

The nearest other settlements in our records are Uchiza (37 km west), Tocache (55 km north), Campo Verde (72 km east-northeast) and Tingo María (95 km south-southwest).

Why the 109 km depth matters

At 109 km this was an intermediate-depth earthquake. Energy from events at this depth spreads out before it reaches the surface, which usually means weaker shaking near the epicentre than a shallow quake of the same magnitude, but shaking felt across a wider area.

This catalogue does not ingest eyewitness responses, so it cannot confirm where this earthquake was felt. Based on magnitude alone, an event this size is often felt across the surrounding area. Its intermediate depth normally reduces peak shaking near the epicentre compared with a shallow event of the same magnitude.

Read more on how focal depth changes what you feel →

What does the tsunami information flag mean?

The USGS record does not carry a link to NOAA tsunami information. That field is not an all-clear and does not state whether a tsunami occurred. In this case, a damaging tsunami would be less likely because at M4.2 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 109 km focal depth is too great to deform the sea floor significantly; it occurred inland rather than beneath the sea floor. For an active coastal alert, use tsunami.gov or your local warning authority.

How earthquakes generate tsunamis, and what the alert levels mean →

Aftershocks and local seismic history

No further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event.

32 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Picota on 01 April 2026. This M4.2 event released about 501 times less energy than that event.

No other earthquakes have been recorded within 100 km of this epicentre in the past year, which makes this a genuinely isolated event.

How long aftershock sequences last, and how large they get →

Where this event sits in the record

This earthquake is part of the March 2025 worldwide record, and of earthquakes in Peru during March 2025. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other recent earthquakes in Peru

All recorded earthquakes in Peru →

Other magnitude 4 earthquakes worldwide

All magnitude 4 earthquakes →

Questions about this earthquake

How strong was the earthquake near San Alejandro?

It measured magnitude 4.2 — a light earthquake. A magnitude 4.2 earthquake radiates roughly 30 tons of TNT equivalent in seismic energy.

How deep was the earthquake near San Alejandro?

The focus was 109 km below the surface, which counts as intermediate.

Was the San Alejandro earthquake felt at the surface?

At magnitude 4.2 and a focal depth of 109 km, the depth spreads the energy out, so shaking is weaker overhead but reaches further.

When did the earthquake near San Alejandro happen?

18 March 2025 at 10:50 UTC.

Was there a tsunami?

No. The USGS record carries no tsunami-information link for this event.

Have there been aftershocks?

No further earthquakes have been recorded within about 150 km of the epicentre in the seven days after this event.

How often do earthquakes happen near San Alejandro?

32 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 6.0 event near Picota on 01 April 2026. This M4.2 event released about 501 times less energy than that event.