Earthquake Alert: M4.8 Event Detected in Japan

An earthquake measuring magnitude 4.8 has been detected near 39 km NE of Kuji, Japan, occurring at 11:58 UTC on Thursday, June 25, 2026. Here is everything you need to know about what happened, what it means, and what to do.

The Basics

According to USGS data, this earthquake originated at a depth of 66.6 km beneath the surface. At a focal depth of 66.6 km, this is classified as a shallow earthquake (0–70 km). Shallow events are typically the most damaging: the seismic energy has less distance to travel before reaching the surface, resulting in stronger and more abrupt ground shaking at the epicentre.

A magnitude 4.8 earthquake is considered a moderate event. In practical terms, this means it is felt strongly by everyone; minor to moderate damage possible in vulnerable buildings.

Why Does This Area Get Earthquakes?

Japan sits at the convergence of the Pacific, Philippine Sea, Eurasian, and North American tectonic plates, making it one of the most seismically active countries on Earth.

Japan experiences roughly 1,500 earthquakes per year that are strong enough to be felt. The country has developed one of the world's most sophisticated earthquake early-warning networks, capable of alerting millions of citizens within seconds of a major rupture.

How Much Energy Is That, Really?

The magnitude scale can be deceptive to non-specialists because it looks like a simple number. In reality, it is logarithmic: each step up releases around 32 times more energy.

A magnitude 4.8 earthquake releases approximately approximately 30,000 tonnes of TNT — comparable to the Hiroshima atomic bomb of energy. For comparison, this exceeds the energy released by most conventional explosive events and is sufficient to shift tectonic stress in measurable ways across a wide region.

Moderate earthquakes are felt by virtually everyone near the epicentre. Strong shaking lasting 10–30 seconds can topple unsecured items, crack plaster, and cause poorly anchored objects to fall. Aftershocks are common following moderate events.

Should People Be Worried?

Significant damage can occur to vulnerable structures — particularly unreinforced masonry, old adobe buildings, and poorly maintained older construction. Well-engineered modern buildings are designed to withstand this level of shaking with minimal structural impact, though contents may shift and non-structural elements (ceilings, partitions) can be damaged.

Aftershocks are a normal part of the earthquake process and should be expected in the hours and days following any notable event. Most aftershocks are smaller than the main shock, but they can be significant — and structures weakened by the main event may be more vulnerable to subsequent shaking.

Staying Safe

Fasten heavy furniture — bookshelves, water heaters, cabinets — to walls using earthquake straps. Store breakable items on lower shelves and heavy items closest to the floor. These simple steps significantly reduce the risk of injury from falling objects.

Understanding the type of building you live or work in is one of the most important steps in earthquake preparedness. Older unreinforced masonry buildings and soft-storey apartment buildings are significantly more vulnerable than modern reinforced concrete or steel-frame structures. If you have concerns, consult a structural engineer.

If you are in Japan, follow J-Alert instructions and refer to local municipal evacuation maps. Many buildings constructed after the 1981 revised building code are designed to withstand strong shaking.

For real-time updates on this earthquake and all seismic activity worldwide, visit our live earthquake map. You can also read our full earthquake safety guide for detailed preparedness advice.

How QuakeWatch Tracks This Event

QuakeWatch sources earthquake data directly from the USGS ComCat (Comprehensive Catalog), which aggregates data contributed by seismic networks worldwide including JMA (Japan), EMSC (Europe and Mediterranean), GFZ (Germany and global), Geoscience Australia, and dozens of national and regional networks. This data is refreshed every 60 seconds, ensuring that new earthquakes appear on our live map within minutes of being processed by the USGS. You can also submit a felt report for this earthquake directly on its detail page.