Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

68 PATA Days 2024 1 2 T H I N T E R N AT I O N A L I N Q U A M E E T I N G O N PA L E O S E I S M O L O G Y , A C T I V E T E C T O N I C S A N D A R C H A E O S E I S M O L O G Y ( PATA ) , O C T O B E R 6 T H - 1 1 T H , 2 0 2 4 , L O S A N D E S , C H I L E K E Y W O R D S Noto earthquake, primary and secondary environmental effects, Japan. (1) Institut de Radioprotection et Sûreté Nucléaire, Fontenay-Aux-Roses, France. (2) Geological Survey of Japan (AIST), Tsukuba, Japan *Email: stephane.baize@irsn.fr Stéphane Baize (1) Takashi Azuma (2) Aurore Laurendeau (1) Marguerite Mathey (1) OVERVIEW OF THE ENVIRONMENTAL EFFECTS DURING THE M7 . 5 NOTO PENINSULA EARTHQUAKE ( 1 / 1 /2024) A B S T R A C T This contribution presents several of the remarkable environmental effects that affected the Noto Peninsula, NW Japan, after the M7.5 earthquake on 1/1/2024. A one-week survey allowed to recognize surface ruptures, including some evidence previously unmapped by other teams, stunning coastal uplift, landsliding and liquefaction. A compilation of published datasets will allow to propose an ESI-scale intensity estimation in a further work. I N T R O D U C T I O N The 2024 New Year’s Day earthquake that hit the Noto Peninsula (NP) in Japan occurred at 16:10 local time (07:10 UTC). Its epicentre is located beneath the Northeastern tip of the NP, close to Suzu city (Figure 1). This region is under NW-SE contraction caused by subduction/collision along the eastern coast of Japan. It led to 245 fatalities and 1300 injuries, mostly inWajima and Suzu, and extensive damage to dwellings and infrastructures, caused both by ground shaking and environmental effects. The NP earthquake was caused by the rupture of a NE- SW trending and south dipping reverse fault at shallow depth, which surface traces could correspond to the offshore Noroshi-oki, Machino-oki and Wajima-oki segments (according to the AIST database). This strong event appears to be the climax of a sequence started in 2020 with other significant events in 2022 (M5.4) and 2023 (M6.5).