Possible climate preconditioning on submarine landslides along a convergent margin, Nankai Trough (NE Pacific)

Abstract

Abstract Submarine landslides are major agents of sediment mass transfer from the shallow to deep sea. Due to their rapid emplacement and tsunamigenic potential, such landslides are significant geohazards for society and off- and on-shore infrastructure. The relationship between climate change and the occurrence of submarine landslides is widely debated. However, there is a lack of continuous long-term submarine landslide records with which to comprehensively understand the relationship between climate-driven forces and submarine landslide occurrence. Here, using oxygen isotope stratigraphy in combination with tephrochronology, we date a 1 Myr continuous record of six landslide deposits (at 13.0–14.2, 323–339, 372–384, 394–413, 508–521, and 857–867 ka) recorded in a slope basin of the Nankai Trough subduction zone, off-shore Japan, which represents the major outcome of this study. The ages of the six landslides coincide mostly with interglacial periods. Thus, we propose that climate forcing might act as a preconditioning factor for slope instability in this active tectonic region. Graphical abstract Location map, lithology, δ18O isotope stratigraphy (black dots) and tephrochronology (pink layers) of drill core C0018A (drilled within the Nankai Through during IODP Exp. 333). δ18O isotope data were correlated with the LR04 stack reference dataset (blue line) of Liesiecki and Raymo (2005). The mass transport deposits (MTD) are dated within odd numbered Marine Isotope Stages (MIS) taken from Bassinot et al. (1994).

Keywords

• Mass transport deposit
• Nankai Trough
• δ18O isotope stratigraphy
• Tephrochronology
• Climate preconditioning