Wetland formation associated with development of a large-scale landslide in Mt. Funagata, NE Japan

Abstract

This study revealed wetland development in the Sugenuma Landslide, a huge translational landslide on the Funagata volcano in the northeastern Japan, based on sediment core analysis obtained from 4 wetlands, ¹⁴C dating and tephrochronology. The Sugenuma landslide was divided into several large-scale masses based on their motion direction and surface roughness. Large-scale wetlands are distributed in between the masses, and small-scale ones are formed in linear depressions on the masses. The three wetlands were formed after 11-12 ka probably associated with a large-scale landslide activity and the other was formed by a secondary small-scale landslide a few centuries before the present. This suggests that wetlands have been formed one after another by subsequent landslide activities which sustains distinctive landscape diversity, including wetland, forest and scarp in a landslide.