Japan: Tsunami Warning after 7.6 Magnitude Earthquake, Waves of Several Metres Expected

An earthquake with a 7.6 magnitude was recorded on Monday 8th December 2025 shortly after 2.15 pm, according to the United States geological survey (USGS). A tsunami warning has been issued.

An important earthquake was felt this Monday, December 8, 2025, offshore japanese North and East coasts, reported the United States geological survey (USGS) around 2:15 p.m. (French time, i.e. 11:15 p.m. Japanese time).

According to the Japan Meteorological Agency, quoted by the news agency Reuters, the epicenter of the earthquake was 80 kilometers offshore aomori Prefecture, to a depth of 50 kilometres. The USGS mentions an earthquake off the coast of Misawa, on the Pacific coast of Japan, at a depth of 53 kilometres.

Tsunami alert triggered

The magnitude of earthquake reached 7.6 on the Richter scale, which justifies the triggering of tsunami warning by the authorities immediately.

As specified by Jérôme Vergne, seismologist at the Strasbourg School and Observatory of Earth Sciences, here are the trends that can be identified following an earthquake, based on the Richter scale:

Between 1 and 3: we hardly notice that an earthquake is in progress;
Between 3 and 4: the earthquake is well felt, for example, on the scale of a department;
From 5: it already does some damage. For example, in Deux-Sèvres [last June 20, Editor’s note], many homes were affected;
Beyond 6: the earthquake destroys fragile buildings and causes victims.

Several people were injured, public television reported NHK quoting a hotel worker in Hachinohe, near Aomori. Live footage shows broken pieces of glass scattered across roads. City residents fled their homes to take refuge in the town hall.

A government spokesperson, Minoru Kihara, urged residents to stay in a safe place until the alert was lifted.

Waves up to three metres expected

The website of the French Ministry of Foreign Affairs confirms that concern is in order, to the extent that “the amplitude of the tsunami generated increases with the magnitude of the earthquake”. And to recall that beyond 8 (which is what the present earthquake in Japan is close to), “the earthquake can generate a potentially devastating tsunami.

Earthquakes with a magnitude greater than 8.7, such as that of Japan on March 11, 2011 and that of Sumatra on December 26, 2004 (9.2), induce major tsunamis which cause sudden flooding and submersion along the coasts of the entire ocean basin concerned. Even if the earthquake occurs thousands of kilometres away, tsunami waves can travel long distances and sweep over seemingly out-of-reach coasts (example of the 2004 tsunami in Indonesia which claimed many lives in Sri Lanka).

The region could know strong aftershocks in the coming days, the government warned at another press conference. According to the Japan Meteorological Agency (JMA), waves up to three metres high could fall on the northeast side of the Japan.

A first wave of 40 cm hit a port in the northern region of Aomori in the evening. A few minutes later, another 40 cm wave reached the town of Urakawa, Hokkaido region. Other waves reached the coast, but none exceeded 70 centimetres, JMA said.