Earthquake.now

M4.5 Earthquake near Saipan, Northern Mariana Islands — 20 August 2026

A light earthquake of magnitude 4.5 was recorded near Saipan, Northern Mariana Islands on , with an epicentre 85 km north of Saipan, at a focal depth of 213.5 km.

4.5 Light

Time (UTC): 2026-08-20 21:57:40

Time (your timezone): —

Magnitude: 4.5 (light)

Focal depth: 213.5 km (intermediate)

Epicentre: 15.9742, 145.6180

Location: 85 km N of Saipan, Northern Mariana Islands

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 4.5 earthquake radiates roughly 85 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 312, 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 →

Where was the epicentre?

The epicentre was located at 15.9742, 145.6180 — 85 km north of Saipan. The closest other recorded event was a magnitude 4.8 earthquake 36 km north of here on 25 June 2025.

Why the 214 km depth matters

At 214 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 M4.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 214 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 13 hours since this event.

29 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.8 event near San Jose Village on 15 December 2025. This M4.5 event released about 89 times less energy than that event.

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

Where this event sits in the record

This earthquake is part of the August 2026 worldwide record. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other magnitude 4 earthquakes worldwide

All magnitude 4 earthquakes →

Questions about this earthquake

How strong is a magnitude 4.5 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 4.5 earthquake radiates roughly 85 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Saipan?

At 214 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.

Was the M4.5 earthquake near Saipan felt?

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.

What does the USGS tsunami field mean for this event?

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 M4.5 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 214 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.

Have there been aftershocks?

No further earthquakes have been recorded within about 150 km of the epicentre in the 13 hours since this event.

How often do earthquakes happen near Saipan?

29 earthquakes of magnitude 4 or above have been logged within roughly 200 km of this epicentre in our catalogue. The strongest was a magnitude 5.8 event near San Jose Village on 15 December 2025. This M4.5 event released about 89 times less energy than that event.