Browse by author
Lookup NU author(s): Professor Takeshi Nakagawa, Dr Tsuyoshi Haraguchi
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Event layers in lake sediments are indicators of past extreme events, mostly the results of floods or earthquakes. Detailed characterisation of the layers allows the discrimination of the sedimentation processes involved, such as surface runoff, landslides or subaqueous slope failures. These processes can then be interpreted in terms of their triggering mechanisms. Here we present a 40 ka event layer chronology from Lake Suigetsu, Japan. The event layers were characterised using a multi-proxy approach, employing light microscopy and mu XRF for microfacies analysis. The vast majority of event layers in Lake Suigetsu was produced by flood events (362 out of 369), allowing the construction of the first long-term, quantitative (with respect to recurrence) and well dated flood chronology from the region. The flood layer frequency shows a high variability over the last 40 ka, and it appears that extreme precipitation events were decoupled from the average long-term precipitation. For instance, the flood layer frequency is highest in the Glacial at around 25 ka BP, at which time Japan was experiencing a generally cold and dry climate. Other cold episodes, such as Heinrich Event 1 or the Late Glacial stadial, show a low flood layer frequency. Both observations together exclude a simple, straightforward relationship with average precipitation and temperature. We argue that, especially during Glacial times, changes in typhoon genesis/typhoon tracks are the most likely control on the flood layer frequency, rather than changes in the monsoon front or snow melts. Spectral analysis of the flood chronology revealed periodic variations on centennial and millennial time scales, with 220 yr. 450 yr and a 2000 yr cyclicity most pronounced. However, the flood layer frequency appears to have not only been influenced by climate changes, but also by changes in erosion rates due to, for instance, earthquakes. (C) 2013 Elsevier Ltd. All rights reserved.
Author(s): Schlolaut G, Brauer A, Marshall MH, Nakagawa T, Staff RA, Ramsey CB, Lamb HF, Bryant CL, Naumann R, Dulski P, Brock F, Yokoyama Y, Tada R, Haraguchi T, Suigetsu 2006 Project Members
Publication type: Article
Publication status: Published
Journal: Quaternary Science Reviews
Year: 2014
Volume: 83
Pages: 157-170
Print publication date: 01/01/2014
Online publication date: 07/12/2013
Acceptance date: 24/10/2013
Date deposited: 30/05/2014
ISSN (print): 0277-3791
ISSN (electronic): 1873-457X
Publisher: Elsevier B.V
URL: http://dx.doi.org/10.1016/j.quascirev.2013.10.026
DOI: 10.1016/j.quascirev.2013.10.026
Altmetrics provided by Altmetric
