COLLABORATIVE RESEARCH: Paleoventilation of the Southwest Pacific and Southern Ocean in the Holocene and late Quaternary

合作研究：全新世和晚第四纪西南太平洋和南大洋的古通风

基本信息

批准号：
0425053
负责人：
Elisabeth Sikes
金额：
$ 18.87万
依托单位：
Rutgers University New Brunswick
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2004
资助国家：
美国
起止时间：
2004-11-01 至 2007-10-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0425053&HistoricalAwards=false
关键词：
COLLABORATIVE RESEARCH Paleoventilation Southwest Pacific

项目摘要

Under this award the PIs will construct a profile of 14C ages for several time slices in the glaciation and deglaciation in order to better constrain past deep water age of the southwest Pacific and Southern Oceans. To do this, the PIs will perform a sediment coring expedition to the subtropical and subantarctic waters to the north and east New Zealand. The cruise will recover multiple cores at each of six locations that are known to contain widespread tephra layers from the from the Taupo volcanic zone on the North Island of New Zealand. These ashes have been well dated on land and provide stratigraphic tie points and a means to establish the relative ages of marine and terrestrial (atmospheric) carbon reservoirs in the past. Previous work on preexisting cores with these ashes has demonstrated that surface and deep water masses in the last glaciation and deglaciation could be centuries older than previously imagined and controversial because surface water reservoir ages in subtropical locations of more than 1900 yrs are considered unlikely even in the glaciation. Continued work to resolve these issues has been hampered because cores from subtropical locations have either insufficient material and/or depth coverage for continued work on 14C and have problematic ash identification. This project will collect giant piston cores to provide sufficient sediment to obtain enough foraminifera from a narrow sediment band surrounding the ashes to properly identify and date the tephras in order to conduct 14C AMS radiocarbon dating foraminifera associated with ash layers in the marine sediment.

根据该奖项，PI 将构建冰期和冰消期多个时间切片的 14C 年龄剖面，以便更好地限制西南太平洋和南大洋过去的深水年龄。为此，PI 将在新西兰北部和东部的亚热带和亚南极水域进行沉积物取芯考察。该邮轮将在六个地点分别回收多个岩心，这些地点已知含有来自新西兰北岛陶波火山区的广泛火山灰层。这些灰烬已在陆地上进行了很好的年代测定，并提供了地层连接点和确定过去海洋和陆地（大气）碳库相对年龄的方法。先前对含有这些灰烬的现有岩心进行的研究表明，末次冰期和冰消期中的地表和深层水团可能比之前想象的要古老几个世纪，并且存在争议，因为即使在亚热带地区，地表水库年龄超过 1900 年也被认为是不可能的。冰川作用。解决这些问题的持续工作受到阻碍，因为来自亚热带地区的岩心材料和/或深度覆盖范围不足以继续进行 14C 工作，并且灰烬识别存在问题。该项目将收集巨型活塞芯，以提供足够的沉积物，以便从灰烬周围的狭窄沉积带中获得足够的有孔虫，从而正确识别和测定碎石年代，以便对与海洋沉积物中灰烬层相关的有孔虫进行 14C AMS 放射性碳测年。