[MIS08-23] Holocene biomass burning history reconstructed from the Lake Suigetsu sediments
Keywords:Biomass burning, Thermal optical transmittance, Benzene polycarboxylic acid, Lake Suigetsu
Observed degradation rates of BC in the natural environment are much lower than those of the organic carbon. Increasing the fire temperature of the biomass burning leads to a decrease of BC degradability due to higher degree of condensation of hydrocarbons. Even under the strong weathering condition in the tropical climate, EC can be stable for more than a century. Although the previous fire researches (paleoclimate rather than modern ecology) reconstructed the amount of BC or charcoals from sediments, the temperature of BC formation has not been discussed well.
Objective of this study is understanding the controlling factors of the thermal character of BC such as aging and provenance in relation to the variabilities of vegetation and human activity in the hinterland as well as burning temperature. For this purpose, BC in the bulk samples are determined with thermal optical transmittance and benzene polycarboxylic acid methods for SG-12 core sediments collected from the Lake Suigetsu. Preliminary results show that fire temperature of soot was higher during stronger East Asian summer monsoon periods for the last 15 kyr.