HR: 1340h
AN: GC13A-0932    [Abstracts]
TI: Holocene and Late Glacial Climate Change in Central Japan
AU: * Adhikari, D P
EM: adhikaridpnpl@yahoo.com, adhikaridp@ntc.net.np
AF: Department of Geology, Tri-Chandra Campus, Tribhuvan University, Ghantaghar, Kathmandu, Bag 13644, Nepal
AU: Kumon, F
EM: shkumon@shinshu-u.ac.jp
AF: Department of Environmental Sciences, Faculty of Science, Shinshu University, Asahi 1-1- 1, Matsumoto, Nag 390-8621, Japan
AU: Koshimizu, S
EM: koshi@yies.pref.yamanashi.jp
AF: Yamanashi Institute of Environmental Sciences, 5597-1, Kenmarubi, Kamiyoshida, Fujioshida, Yamanash, Yam 403-0005, Japan
AB: In an attempt to reconstruct the climate for the last 40 ka in central Japan, sediment cores from Lake Aoki, located close to the northern Japanese Alps, and Lake Yamanaka, at the northern foot of Mt. Fuji, were investigated for grain-size, diatoms, and total organic carbon (TOC) and total nitrogen (TN) contents. TOC flux and diatom abundance are closely positively correlated in both short-and long-term fluctuations. Changes in surface water temperature and paleohydrology appear to be the main factor affecting the variability in the proxy records. An abrupt decrease in sand and clay contents and increase in TOC flux and diatom abundance at 13 ka cal BP is interpreted as the last Glacial Holocene boundary. During the Glacial Period, more cooling events centered ca. 16, 28, 34, and 39 ka cal BP can be correlated with the Henrich events H1, H2, H3 and H4, respectively. The Last Glacial Maximum reaches its peak ca. 22 ka cal BP. Beginning with a rapid warming, the Holocene climate history is characterized by an alternating sequence of seven warm and seven cool phases with abrupt transition and lengths lasting from hundreds to thousands of years. Climatic events such as the Little Ice Age (LIA), the Younger and Older Dryas, the Medieval Warm Period, and the Holocene Optimum are evident, and some other warm and cool events not previously well recorded are also apparent. Generally, the Holocene was warmer than the present time but cool periods even colder than the LIA are also observed. The magnitude of climate change observed after the LIA was commonplace in the Holocene.
UR: http://www.agu.org
DE: 1600 GLOBAL CHANGE
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting