The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
On 1 January 2024, the Mw=7.5 Noto Peninsula Earthquake struck the Ishikawa Prefecture in Japan. AS of the time of writing, 168 people are known to have lost their lives, whilst up to 323 are currently missing. A week after the event, there is little prospect of further survivors being found, but some of those reported missing may be safe elsewhere.
As expected from a reverse fault earthquake occurring just offshore a populated area, the earthquake triggered tsunami waves (fortunately of limited size) and building collapses. However, the earthquake has also triggered many substantial landslides (some reports indicate over 1,000, although this number will rise once a full inventory has been created), which have served to kill people directly and to hinder the rescue operations, most notably through the blockage of roads, increasing the loss of life from structural collapses.
The most dramatic image of these landslide is a video that has been widely posted to social media from Wajima. NBC has posted this to Youtube:-
Some early work has been undertaken to map the landslides triggered by the Noto Peninsula Earthquake. In the first instance, this is likely to be some of the larger failures. The Geospatial Information Authority of Japan has tweeted this map showing “slope failure locations and soil accumulation locations” – this data is also available online:-
There are some fascinating clusters of landslides, which will be interesting to understand. Two of these are located inland, but there is also a distinct cluster along the coast, where there are steep slopes that are likely to be out of equilibrium.
They have also posted aerial images online, with agreements that the data can be used and shared. There are some analyses already of the landslides shown in these images, some of which are startling:-
Meanwhile, there are some stunning images of the landslides triggered by the earthquake, including this one:
The caption describes this as “National Route 249 near Minamishimi in the city, which was cut off by a landslide.”