5:15 PM - 6:30 PM
[HCG26-P09] Verification of the method to reconstruct histories of crustal uplift rate from river longitudinal profiles: Application to the central part of Boso Peninsula, Japan
Keywords:river longitudinal profile, inverse analysis, erosion
Here, we aim to verify the method for analyzing river profiles in tectonically active regions where the uplifting rates of bedrock varies in smaller spatial and temporal scales. We investigated uplift rate histories of the central part of the Boso Peninsula in Japan, and examined the effectiveness of the method, comparing results of multiple rivers that locate in same region. As a result, we found that the uplift rate histories estimated from multiple rivers were inconsistent each other although they locate on the same tectonic terrain. We infer that cause of this inconsistency in estimated uplifting histories can be attributed to the heterogeneity in erodibility of the bedrock in the study area. The forward model employed in this study assumes that the erodibility of bedrock is constant in space; however, several knickpoints actually locate at the lithological boundaries, suggesting the possibility that variation in erodibility should be taken account in the model. Thus, we suggest that parameterization of physical controls such as lithologic variation is significant in order to improve the method to estimate uplift rate histories from longitudinal river profiles in tectonically active regions.