The concentration and distribution of heavy minerals in tsunami deposits is not random and mostly source-dependent. Heavy minerals may thus be good indicators of sediment provenance and tsunami flow dynamics. The tsunamis generated by the 1996 phreato-magmatic eruption in Karymskoye Lake represent a relevant case-study because the provenance of the abundant heavy minerals found in the tsunami deposits is well constrained (the on-going basaltic eruption itself). X-ray computed tomography (X-CT) of cores of tsunami sediments is used to identify heavy minerals and characterise their source and spatial distribution in the tsunami deposit, and to propose a scenario of the coupled eruption and tsunamis. An original combination of methods including X-CT, SEM and XRF core scanner allows distinguishing subunits corresponding to pulses of sediments deposition and associated inputs of heavy minerals, together with erosive contacts, laminations, and rip-up clasts of the substratum. The structure of the tsunami deposits suggests that a major tsunami consisting of two main waves inundated the coastal terrace up to 100m inland on the eastern shore of the lake; a scenario that is consistent with waves generated by experimental explosions. This largest tsunami might have occurred when underwater explosions were at a critical water depth of 40m (corresponding to a two-third submerged explosion in the 60m deep lake). However, more investigations are needed to better understand the critical conditions leading to a tsunami during underwater eruptions.
Marine Geology – Elsevier
Published: Feb 1, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.
All for just $49/month
It’s easy to organize your research with our built-in tools.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud