A deadly earthquake jolted Ishikawa Prefecture off Japan's western coast on the first day of 2024, killing at least 64 people and damaging thousands of houses and infrastructure.

Aftershocks continued to shake the prefecture and nearby areas. Over 300 tremors have been detected since the quake first hit on Monday, according to Japan Meteorological Agency (JMA).

Japan is located in one of the most active seismic regions in the world, with the whole country at risk of being affected by quakes. Here's what you need to do about this quake and the reasons why the country is frequently hit by powerful quakes.

What happened?

A magnitude-7.6 earthquake struck the Noto region in Ishikawa Prefecture on Monday afternoon, prompting people in western coastal areas to flee to higher ground as tsunami waves swept cars and houses into the water. Satellite images show that homes along the coastline near Ukai were flooded, leaving a muddied coastline.

The JMA issued a warning for a wave of up to five meters on January 1, but it lifted all tsunami alerts on Tuesday at 10 a.m. after recording a wave of at least 1.2 meters in height. Weather officials warned that strong aftershocks may occur in the week, especially over the next two to three days.

In Suzu, a city of just over 5,000 households near the quake's epicenter, 90 percent of houses may have been destroyed, according to its mayor, Masuhiro Izumiya.

In another city, Wajima in Ishikawa, a fire was sparked by the quake, resulting in about 200 buildings being burned. Residents were warned of rainstorms and landslides on Wednesday.

As of 7 a.m. on Wednesday, power supply to about 35,000 households in the prefectures of Ishikawa and Niigata was cut off, and 67 gas stations were suspended.

Japan's Prime Minister Kishida Fumio said at a news conference that the government will strengthen its support for people suffering from the disaster, NHK reported Wednesday.

Kishida pledged to prioritize saving lives. He said that he has increased the number of Self-Defense Forces (SDF) to be mobilized in disaster zones to 2,000. He said the SDF and police will more than double the number of rescue dogs.

Why did the quakes occur in a cluster?

Past instances show there is a risk of up to 20 percent that another quake of the same size could take place, JMA said in a press briefing. Residents in the area continue to be hit by frequent aftershocks, which are putting structures in the region at even greater risk.

There are a number of active faults off the Noto Peninsula, with the compression pushing underground plates together and forcing one above the other, according to Japan's Headquarters for Earthquake Research Promotion. This is known as a reverse-type fault mechanism. Earthquakes have been increasing in the area since 2018, with seismic activity becoming higher over the past three years.

There were more than 14,000 small earthquakes occurring off the Noto region in seismic swarm from November 2020 to February 2023 with a magnitude of 1 or more, according to a paper by experts at Japanese universities. 

Considering the changes in crustal deformation zones in the region, it's possible that fluid movements were involved in earlier quakes, according to a report released by the government's earthquake research council.

The biggest earthquake in the Noto Peninsula over the last century was the Noto-Hanto earthquake that occurred on March 25, 2007 with a magnitude of 6.9.

Major earthquakes in Japan

An earthquake measuring 6.6 magnitude struck Iburi Subprefecture in southern Hokkaido, Japan, in 2018, which is the highest level observed on the island since 1923, when JMA made the first record. The earthquake disrupted electrical service throughout Hokkaido, leaving 44 people dead and 5.3 million residents without power.

In Japan, thousands of people have died due to major earthquakes in recent decades, with a large part of the northern region needing to be rebuilt after what is locally called the Great East Japan Earthquake of 2011. That earthquake and subsequent tsunami resulted in over 15,000 deaths, and thousands of victims were never recovered. The disaster also resulted in Japan's worst nuclear disaster at Tokyo Electric's Fukushima plant.

In 1995, more than 6,000 people died in the Kobe earthquake, while in more recent years, the Kumamoto earthquake in 2016 killed over 200 people. The death toll from an earthquake that struck Tokyo in 1923 is believed to have exceeded 100,000, according to official statistics.

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