著者

Kawamura Kimitaka Izawa Yusuke Mochida Michihiro Shiraiwa Takayuki

出版者

Elsevier

雑誌

Geochimica et Cosmochimica Acta (ISSN:00167037)

巻号頁・発行日

vol.99, pp.317-329, 2012-12-15

被引用文献数

91

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We successfully detected biomass burning tracers including levoglucosan and vanillic, p-hydroxybenzoic and dehydroabietic acids in an ice core (153 m long, ca. 300 years old) taken from Ushkovsky ice cap (altitude, 3903 m), the Kamchatka Peninsula, Northeast Asia. Concentrations of total organic carbon (TOC) were also determined in the ice core. Levoglucosan, which is produced by pyrolysis of cellulose and hemicellulose and thus is a general tracer of biomass burning, showed sporadic peaks in the years of 1705, 1759, 1883, 1915, 1949 and 1972, with the largest peak in 1949. However, its concentrations did not show a systematic increase in the last century although the concentration peaks seemingly corresponded to the higher ambient temperatures in the northern high latitudes. In contrast, dehydroabietic acid, a specific tracer of the pyrolysis of conifer resin, showed a gradual increase from the early 1900s to 1990s with a significant peak in 1970. Contributions of dehydroabietic acid to TOC also showed an increasing trend for the 20th century. Similarly, vanillic and p-hydroxybenzoic acids presented higher concentrations in the last half-century with sporadic peaks in 1705, 1759 and 1949. This study showed that general biomass burning tracers such as levoglucosan have been sporadically transported over the glacier of the Kamchatka Peninsula. In contrast, the ice core record of dehydroabietic acid indicated that fires of boreal conifer forest have more frequently and increasingly occurred in Far East and Siberia during the last century and transported to the Northwestern Pacific. The present study demonstrates that organic tracers of biomass burning preserved in ice core could provide historical records of biomass burning and boreal forest fires.