Seismogenic liquefaction with M ∼ 3.5 in fine-grained sediments: An experimental approach

Abstract

Seismically liquefaction-induced soft-sediment deformation structures are key to understanding the geological history of earthquakes and sedimentary environments. These evidences usually have been associated with high-magnitude seismic events, above 5. However, the precise thresholds and mechanisms, especially for lower-magnitude earthquakes, remained unclear. This study aims to address this gap by experimentally investigating the development of deformation structures under controlled laboratory conditions. Using three sediment types arranged in five sequences, the sediments were subjected to low-magnitude seismic vibrations. Developed liquefaction features such as clastic volcanoes, pseudonodules, flame structures, and load casts were measured by a novel morphometric analysis to quantify their size and shape. The findings revealed that even at a magnitude of ∼3.5, liquefaction and deformation structures can occur, especially in high water-saturated fine-grained sediments. These results provide new insights into the thresholds of seismically-induced liquefaction and highlight the importance of considering lower-magnitude events in seismic risk assessments, offering significant implications for the study of sedimentary processes and earthquake-related deformation.