Earthquake.now

M4.1 Earthquake near Shima, Japan — 17 September 2026

A light earthquake of magnitude 4.1 was recorded near Shima, Japan on , with an epicentre 89 km south-southeast of Shima, at a focal depth of 363.4 km. It ranked as the 42nd strongest of 43 earthquakes recorded in Japan in the preceding 30 days.

4.1 Light

Time (UTC): 2026-09-17 05:42:28

Time (your timezone): —

Magnitude: 4.1 (light)

Focal depth: 363.4 km (deep)

Epicentre: 33.5744, 137.1730

Location: 89 km SSE of Shima, Japan

Country: Japan

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 4.1 earthquake radiates roughly 21 tons of TNT equivalent in seismic energy.

The USGS assigns this earthquake a significance score of 259, 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 14:51 local solar time at the epicentre, during the afternoon.

This event was deeper than 93% of the 1,230 earthquakes recorded in Japan in our catalogue and stronger than 5% of them.

Where was the epicentre?

The epicentre was located at 33.5744, 137.1730 — 89 km south-southeast of Shima. The closest other recorded event was a magnitude 4.6 earthquake 35 km southwest of here on 04 July 2026.

The nearest other settlements in our records are Kumano (35 km southwest), Shima (54 km east), Shingū (75 km west) and Iwata (87 km northeast).

Why the 363 km depth matters

At 363 km this was a deep-focus earthquake, occurring well inside the subducting slab rather than in the crust. Deep events are rarely damaging even at large magnitudes, though they can be felt over very long distances.

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 deep focus normally weakens surface shaking while spreading perceptible motion over a broad area.

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 M4.1 it falls below the magnitude 6.5 threshold that generally applies before a submarine earthquake displaces enough water to generate a damaging tsunami; its 363 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 1 day since this event.

36 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 Shingū on 26 February 2025. This M4.1 event released about 355 times less energy than that event.

5 earthquakes have been recorded within 100 km of this epicentre in the past year, 1 of them in the past 30 days.

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

Where this event sits in the record

This earthquake is part of the September 2026 worldwide record, and of earthquakes in Japan during September 2026. Browse the full monthly archive to compare periods.

Nearest recorded earthquakes to this epicentre

Other recent earthquakes in Japan

All recorded earthquakes in Japan →

Other magnitude 4 earthquakes worldwide

All magnitude 4 earthquakes →

Questions about this earthquake

How strong was the earthquake near Shima?

It measured magnitude 4.1 — a light earthquake. A magnitude 4.1 earthquake radiates roughly 21 tons of TNT equivalent in seismic energy.

How deep was the earthquake near Shima?

The focus was 363 km below the surface, which counts as deep.

Was the Shima earthquake felt at the surface?

At magnitude 4.1 and a focal depth of 363 km, the depth spreads the energy out, so shaking is weaker overhead but reaches further.

When did the earthquake near Shima happen?

17 September 2026 at 05:42 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 1 day since this event.

How often do earthquakes happen near Shima?

36 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 Shingū on 26 February 2025. This M4.1 event released about 355 times less energy than that event.