Sea-level fluctuations control the distribution of highly liquefaction-prone layers on volcanic-carbonate slopes

Abstract Understanding and quantifying the hazards related to earthquake-induced submarine liquefaction landslides are particularly significant offshore of tropical volcanic-carbonate islands, where carbonate production competes with volcanism create highly contrasted lithological successions. To improve detection liquefaction-prone layers, we analyzed physical properties mineralogy performed 70 dynamic triaxial tests on 25 sediment cores eastern side Mayotte (Comoros archipelago in western Indian Ocean) an area that has experienced seismicity since 2018. We found main parameter controlling potential is presence low-density layers high calcite content accumulating along slope during lowstands. This phasing sea-level fluctuations implies a recurrent geohazard for islands worldwide. Furthermore, relationship between cyclic resistance its density magnetic susceptibility represents time-effective approach identifying liquefaction.