The role of global and local factors in determining the middle to late Holocene environmental history of the South Kurile and Komandar islands, northwestern Pacific
The role of global and local factors in determining the middle to late Holocene environmental history of the South Kurile and Komandar islands, northwestern Pacific
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全球和地方因素在决定西北太平洋南千岛群岛和科曼达尔群岛中晚期全新世环境历史中的作用
DOI：
10.1016/j.palaeo.2004.02.023
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
V. Bazarova
中科院分区：
文献类型：
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作者：
N. Razjigaeva;T. Grebennikova;L. Ganzey;L. Mokhova;V. Bazarova
西北太平洋岛屿全新世沉积物的研究对于了解该地区在海洋气候、小气候强变率和海流对比影响下的自然发育具有重要意义。白令岛的全新世剖面记录了以下事件：约4600-4500年BP的冷却；约3500-3400年BP变暖；在3000年BP左右冷却；约2700 BP时海平面上升（高达1.5米）；在大约1800-1400年BP冷却；海平面在大约1000年前上升。在南千岛群岛，大约7000-6500年前，干燥和凉爽的气候转变为温暖和潮湿，比北海道岛晚。此时，黑潮系统变得更加活跃，桦树组合被寒温带阔叶林和针叶林/阔叶林混合林所取代。在全新世最佳时期（约6000年），温带阔叶林几乎占据了库纳希尔和伊图鲁普鄂霍次克一侧的全部地区，气候比现在温暖。在6500 ~ 6300 yr BP左右达到的最高海平面位置比现在高2.5 ~ 3 m。在4700 ~ 4500年BP的变冷过程中，海岛植被受暖流影响略有变化。这一时期的主要海平面下降导致了广泛的海岸沙丘场的形成。晚全新世初期的增温几乎与全新世最佳期相当。两次轻微的违法行为被记录在案。晚全新世下半叶发生的植被变化和气候恶化，导致热生植物类群消失或自然栖息地南移。1700 ~ 1300 yr BP降温期间，地峡面积增加，形成了带湖泊的滨海湿地和带古土壤的滨海沙丘，形成了草地和沼泽景观。晚全新世变暖并不强烈。火山对环境的影响导致了植被组合的变化，该地区的沼泽和厚厚的土壤剖面的形成。
The study of Holocene deposits from northwestern Pacific Islands is very important for understanding the natural development of the area in the context of oceanic climate, strong microclimate variability, and the influence of contrasting marine currents. Holocene sections from Bering Island record the following events: cooling at about 4600–4500 yr BP; warming at about 3500–3400 yr BP; cooling at about 3000 yr BP; sea-level rise (up to 1.5 m) at about 2700 BP; cooling at about 1800–1400 yr BP; and sea-level rise at about 1000 yr BP. On the South Kuriles, a dry and cool climate changed to warm and moist about 7000–6500 yr BP, later than on Hokkaido Island. At this time, the Kuroshio Current system became more active and birch assemblages were replaced by cool–temperate broadleaf forests and mixed coniferous/broadleaf forests. At the Holocene Optimum (about 6000 yr BP), temperate broadleaf forest occupied almost all of Kunashir and the Okhotsk side of Iturup and the climate was warmer than present. The highest sea-level position reached was 2.5–3 m above present level about 6500–6300 yr BP. During the cooling about 4700–4500 yr BP, island vegetation changed slightly due to the influence of warm currents. Major sea-level regression during this period led to the formation of extensive coastal dune fields. The warming at the beginning of the late Holocene was almost as great as that of the Holocene Optimum. Two minor transgressions are recorded. The vegetation changes and climatic deterioration that took place in the second half of the late Holocene resulted in either a disappearance of thermophylous taxa or in a southward shift of their natural habitats. During the cooling from 1700 to 1300 yr BP, the isthmus area increased, coastal wetlands with lakes and coastal dunes with paleosols were formed, and grassland and swamp landscapes developed. Late Holocene warming was not intensive. Volcanic impact on environments led to changes in vegetation assemblage, swamping of the area, and thick soil profile formation.