A research team from the University of Tokyo and other institutions found that multiple seafloor faults caused the tsunami during the Noto Peninsula earthquake [1].
This discovery provides critical insight into how complex underwater geological structures can amplify water displacement, potentially refining future tsunami warning systems for coastal regions.
The earthquake occurred on Jan. 1, 2024 [3]. According to the study, the tsunami was triggered by the formation of a deformation zone where several faults concentrated on the seabed [2]. This specific zone measured approximately 30 kilometers in length [2].
Researchers identified the width of this deformation zone as being between 2.5 and 3.8 kilometers [2]. The data shows that the seabed experienced a maximum uplift of about six meters within this area [2].
Beyond the primary deformation zone, the team discovered even more significant geological traces. They observed maximum uplift amounts of 60 meters or more in the surrounding areas [2]. This figure is more than 10 times the maximum uplift recorded within the immediate tsunami source zone [2].
The findings highlight a discrepancy in how fault movement is measured. While the deformation zone linked to the tsunami was approximately 30 kilometers long [2], other reports suggest the linked length of active faults was revised to 252.5 kilometers [2].
The research team focused their investigation on the seabed off the northeast coast of the Noto Peninsula to map these movements [2].
“Multiple seafloor faults caused the tsunami during the Noto Peninsula earthquake.”
The identification of a concentrated deformation zone suggests that tsunamis can be generated not just by a single massive rupture, but by the interaction of multiple smaller faults. By proving that seafloor uplift can reach 60 meters in surrounding areas, this research challenges previous assumptions about the scale of seabed displacement during such events, which may lead to more accurate risk assessments for other fault-dense regions.
