Testing an arc volcanism - climate link in a high-latitude Plio-Pleistocene marine tephra archive at ODP Site 882 (northwest Pacific)

测试 ODP 站点 882（西北太平洋）高纬度上里欧-更新世海洋火山灰档案中的弧火山活动与气候之间的联系

• 批准号: 1950006
• 负责人: Susanne Straub
• 金额: $ 29万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1950006&HistoricalAwards=false
• 关键词: Testing; arc; volcanism; climate; link

This project explores high latitude volcanic activity. It is hypothesized that the volcanic activity is linked to cyclic variations in Earth’s climate, especially the growth and shrinking of terrestrial ice sheets during the glacial / interglacial cycles of the last ~2.6 million years. Sediment cores will be studied that were recovered by ocean drilling as part of the multi-national Ocean Drilling Program (ODP). In those cores the number and composition of ash layers produced by the volcanoes of Kamchatka Peninsula and the Aleutian Islands will be measured. Current data show a strong increase of volcanic activity at the beginning of the Earth’s most recent glacial period, 2.6 million years ago. That increase was followed by periodic changes in how often volcanoes erupt. This study will show whether those volcanic cycles are timed with orbitally-driven climate cycles through that 2.6 million year period, which would be expected if Earth’s volcanism was linked to global climate cycles. The project will be carried out by international team of researchers from the United States, Australia and Mexico that includes igneous geochemists and climate scientists. The team is led by a women scientist with a disability. The project provides opportunities for graduate and undergraduate student training, for connecting with colleagues in Russia and Germany who work on complementary projects, and for outreach to K-12 teachers and students and to the general public. The proposed project will test the glacio-volcano hypothesis whether the increase in marine fallout ash bed frequency at ~2.6 Ma and its subsequent fluctuation in the North Pacific is causally related to the Pleistocene ice cycles. This will be done by means of the Plio-Pleistocene ash bed record drilled in two holes at ODP Site 882 (Leg 145), which are 100% recovered by advanced piston coring (APC)-techniques and that contain a rich and time-precise, late Pliocene to Recent ash bed record from high-latitude volcanic arcs where the effects of global glaciation cycles are strongest. The team will obtain a revised, detailed lithostratigraphic description of the Site 882 ash beds, and augment the existing compositional data by additional major and trace element analyses, including Cl, and Pb and Nd isotope ratios in order to test whether (i) Milankovitch periods are present in the ash bed series; (ii) there is a tell-tale change in ash bed cyclicity across the Mid-Pleistocene Transition (~0.7-1.1 Ma); (iii) ash bed cyclicity is affected by provenance from different arcs; and (iv) there is a magmatic control on ash bed cyclicity. The study could provide an answer to whether tempos of explosive arc volcanism as recorded in the marine ash bed series are paced by glaciation, or whether such signals are largely lost in the maze of other processes that influence the timing of explosive arc volcanism.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目探索高纬度火山活动。据推测，火山活动与地球气候的周期性变化有关，特别是在过去约 260 万年的冰期/间冰期循环期间陆地冰盖的增长和收缩。作为多国海洋钻探计划（ODP）的一部分，将研究通过海洋钻探回收的沉积物岩心。在这些岩心中，将测量堪察加半岛和阿留申群岛火山产生的火山灰层的数量和成分。目前的数据显示，在地球最近的冰期（260 万年前）开始时，火山活动急剧增加。随着火山喷发频率的周期性变化，火山喷发频率也随之增加。这项研究将表明这些火山周期是否与这 260 万年期间轨道驱动的气候周期同步，如果地球的火山活动与全球气候周期相关，那么这就是预期的。该项目将由来自美国、澳大利亚和墨西哥的国际研究小组执行，其中包括火成岩地球化学家和气候科学家。该团队由一名残疾女科学家领导。该项目为研究生和本科生培训、与俄罗斯和德国从事互补项目的同事建立联系、以及向 K-12 教师和学生以及公众进行推广提供了机会。 拟议的项目将测试冰川火山假说，以确定约2.6 Ma海洋沉降灰床频率的增加及其随后在北太平洋的波动是否与更新世冰循环存在因果关系。这将通过在 ODP 站点 882（第 145 段）的两个孔中钻取的上新世灰床记录来完成，这些记录通过先进的活塞取芯 (APC) 技术 100% 恢复，并且包含来自全球冰川循环影响最强的高纬度火山弧的丰富且时间精确的上新世晚期到近期灰床记录。该团队将获得882号站点灰层的修订后的详细岩石地层描述，并通过额外的主要和微量元素分析（包括Cl、Pb和Nd同位素比）来扩充现有的成分数据，以测试（i）灰层系列中是否存在米兰科维奇周期； (ii) 在中更新世过渡期（~0.7-1.1 Ma），灰床周期性发生了明显的变化； (iii) 灰床周期性受到不同弧源的影响； (iv) 火山灰床的周期性受到岩浆控制。这项研究可以回答海洋灰床系列中记录的火山弧爆发速度是否受到冰川作用的影响，或者这些信号是否在影响火山弧爆发时间的其他过程的迷宫中很大程度上丢失。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。