StEER: Noto Peninsula Earthquake Preliminary Virtual Reconnaissance Report

On January 1, 2024, a powerful earthquake with a magnitude of Mj 7.6 (Mw 7.5) struck the Noto
Peninsula in Japan, at a focal depth of 10 km. This seismic event was characterized by a
significant under-ocean fault rupture over 100 km, leading to major crustal deformation, strong
ground motion, and a tsunami, with a notable 4.0 m uplift of the ocean floor.
The Japan Meteorological Agency (JMA) recorded a maximum intensity of 7 on their scale in Sika
Town and Wajima City, with substantial impacts felt up to 300 km away. Ground motion
parameters such as Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV) exceeded
1,000 cm/s2 and 100 cm/s, respectively, suggesting potential structural damage beyond the
design basis for extremely rare seismic events. Acceleration and displacement spectra at the sites
with extensive building and lifeline damage show high response in the 1.0-2.0 sec range, likely
due to relatively soft soil conditions.
The earthquake severely impacted Ishikawa Prefecture, damaging at least 96,000 structures,
including traditional timber houses, historical temples, and shrines. Damage was exacerbated by
soft soil conditions, particularly affecting aged timber housing and low-rise non-ductile reinforced
concrete (RC) buildings. Steel buildings generally survived the shaking unless they had poor
welding details. Significant damage to steel structures also included buckling of braces in parking
structures and damage to cladding materials.