Tsunamis are capable of causing large-scale erosion, transport, and rapid burial of seafloor materials, yet direct observations of their effects on biological remains in modern marine environments are extremely rare. Here, we document tsunami-driven transport and burial of experimentally deployed whale bones in Tsukumo Bay, Japan, following the 2024 Noto Peninsula Earthquake (Mw 7.5), which occurred on 1 January 2024 at 16:10 (JST).
Post-tsunami scuba surveys found 16 whale bone elements, including skulls, jaws, and vertebrae; some bones were damaged, one vertebral series remained articulated. All found bones were transported offshore to water depths of ~20 m, with minimum horizontal transport distances exceeding 30 m and a maximum of ~70 m. Most bones were associated with tongue-shaped gravel accumulations formed under influence of landslide-triggered debris flow and propagated tsunami, suggesting that whale bones and gravel- to boulder-sized clasts exhibited similar hydrodynamic behavior during tsunami backwash.
A sediment core collected adjacent to a skull records a sharp erosional surface overlain by cross-laminated sand and homogeneous mud, indicating tsunami erosion followed by rapid sediment redeposition. These observations provide rare empirical constraints on tsunami-induced early taphonomic processes, such as transport, destruction and burial, of vertebrate remains, offering valuable analogs for interpreting fossil assemblages.

抄録全体を表示