New Research Results Show 19 Square Kilometers of Land Underwent Liquefaction in Noto Peninsula Earthquake; Amount Thought to be Increased by Sand Blown in from Sea of Japan

The Yomiuri Shimbun

16:03 JST, November 25, 2025

Ground liquefaction caused by last year’s Noto Peninsula Earthquake is estimated to have damaged a total of 19.21 square kilometers of land across 34 municipalities in Ishikawa, Toyama, Niigata and Fukui prefectures, research by the National Research Institute for Earth Science and Disaster Resilience (NIED) has shown.

According to the Tsukuba, Ibaraki Prefecture-based Institute, the damaged areas amount to 410 times as much ground space as that taken up by Tokyo Dome stadium and represent about quadruple the damage from the 2016 Kumamoto Earthquake.

It was also confirmed that some places which had suffered liquefaction in prior earthquakes experienced re-liquefaction when the 2024 quake occurred.

Liquefaction is a phenomenon in which the ground becomes softer due to the shaking from an earthquake. It tends to occur in places where the soil is sandy and on pieces of reclaimed land.

Shigeki Senna, a senior researcher at the NIED who is an expert on structural and seismic engineering, confirmed traces of eruptions of sand and water in the quake-hit areas.

The affected land areas were divided into squares of about 25 meters on each side. If anywhere within a square showed evidence of liquefaction, the entire square was regarded as having been damaged by the phenomenon. The total area was calculated in this way.

By prefecture, the largest amount of liquefaction damage was seen in Ishikawa Prefecture, with 11.92 square kilometers affected, more than 60% of the total.

This was followed by 3.71 square kilometers in Niigata Prefecture, 3.47 square kilometers in Toyama Prefecture and 0.12 square kilometers in Fukui Prefecture.

Using the same method, the area of land affected by liquefaction after the 2011 Great East Japan Earthquake was calculated at 39.09 square kilometers, 836 times the ground area of Tokyo Dome.

In regions facing the Sea of Japan, strong winds carry sand inland from the seashore. It is thought that the existence of geological strata containing large amounts of sand made liquefaction easier, resulting in damage over a wide area.

At the time of the 2007 earthquake in the Noto Peninsula, Nanao, Ishikawa Prefecture, was hit by strong tremors. At least 13 areas of the city that were near the sea suffered from re-liquefaction due to the 2024 quake.

The ground under the town of Uchinada, Ishikawa Prefecture, experienced large-scale horizontal sliding.

In the same town, two locations which experienced liquefaction in the 1891 Nobi Earthquake, the epicenter of which was in Gifu Prefecture, were found to have suffered from re-liquefaction in last year’s quake.