FESD Type I: VOICE - Volcano, Ocean, Ice, and Carbon Experiments

FESD I 型：VOICE - 火山、海洋、冰和碳实验

• 批准号: 1338832
• 负责人: Charles Langmuir
• 金额: $ 417.47万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1338832&HistoricalAwards=false
• 关键词: FESD; Type; VOICE; Volcano; Ocean

Two of the major phenomena on Earth are ice ages and volcanic eruptions. This research addresses the question how these two seemingly unrelated aspects of our planet may influence one another. One causal link between the two is the pressure exerted by ice and the oceans on Earth's interior. Volcanism is sensitive to such changes in pressure. A second causal link occurs because volcanoes are the ultimate source of natural CO2 delivered to the atmosphere, and CO2 has a marked influence on climate. During an ice age cycle, vast quantities of water are transferred between continents and oceans, eliminating thick ice sheets and changing sea level. Melting ice uncorks volcanoes, leading to a pulse of much more active continental volcanism for several thousand years. Glacially induced sea level change should influence how much Earth's interior melts beneath ocean ridges. As sea level rises and falls the amount of melt delivered to make the ocean crust should vary by about ten percent, leading to changes in the thickness of the ocean crust and the depth of the sea floor. This could be the explanation for the undulating topography of the sea floor known as abyssal hills. The changes in volcanism at ocean ridges could also lead to changes in hydrothermal activity that would influence deep sea ecosystems and affect geochemical budgets of the oceans. The large volcanic pulse following de-glaciation could add large amounts of CO2 to the atmosphere, contributing to the rapid warming that occurs at the end of ice ages. Ultimately, a better understanding of the influence of volcanic CO2 emissions on climate could provide an important context for understanding the significance of human CO2 emissions. To test these potential relationships, we combine novel new observations with quantitative modeling. High resolution maps of the sea floor will provide the bathymetric data to test whether abyssal hills vary with climate cycles. New sediment cores near ocean ridges will reveal whether hydrothermal activity also varies with glacial cycles, and how much it varies. Sampling and analysis of the volcanic rocks of the sea floor will show how melting of Earth's interior varies over time. The sea-going work will take place on two cruises, one on a U.S. oceanographic vessel and the other in collaboration with German investigators. On land, we will collaborate with leading volcanologists from the U.S. Geological Survey to investigate the volcanic signal of Cascades volcanoes over recent glacial cycles. Newly measured ages will constrain the timing of the volcanic response to glaciation. Geochemical analyses will constraint how volcanism responds to glacial changes, and how much CO2 emissions may vary. Modeling work will investigate exactly how changes in ice sheets and sea level cause pressure changes beneath volcanic regions on land and undersea, and generate quantitative models of melting of Earth's interior and how it responds to sea level change. The final aim is an integrated model that links volcanism, CO2 and climate and tests how they may interact with one another over time periods of many glacial cycles. In essence, we are exploring the coupling between Earth's interior and Earth's climate, perhaps discovering that even the fabric of the ocean floor may be responding to climate change ultimately caused by variations in the amount of solar energy our planet receives, and that glacial cycles are influenced by the pulse of the solid Earth.

地球上的两个主要现象是冰河时代和火山爆发。 这项研究解决了我们星球上这两个看似无关的方面如何相互影响的问题。 两者之间的一个因果关系是冰和海洋对地球内部施加的压力。 火山活动对这种压力变化很敏感。 第二个因果关系的出现是因为火山是自然界二氧化碳排放到大气中的最终来源，而二氧化碳对气候有显著的影响。 在冰河时代的循环中，大量的水在大陆和海洋之间转移，消除了厚厚的冰盖并改变了海平面。 融冰打开火山的瓶塞，导致数千年来更加活跃的大陆火山活动。 冰川引起的海平面变化应该会影响洋脊下地球内部融化的程度。 随着海平面的上升和福尔斯的下降，形成洋壳的熔融物的数量会变化大约10%，从而导致洋壳厚度和海底深度的变化。 这可以解释为什么海底地形起伏，被称为深海丘陵。 洋脊火山活动的变化也可能导致热液活动的变化，从而影响深海生态系统和海洋的地球化学收支。 冰川消融后的大规模火山爆发可能会向大气中增加大量的二氧化碳，导致冰河时代结束时发生的快速变暖。 最终，更好地了解火山二氧化碳排放对气候的影响可以为理解人类二氧化碳排放的重要性提供重要背景。 为了测试这些潜在的关系，我们将联合收割机的新观察与定量建模相结合。 高分辨率海底地图将提供测深数据，以检验深海丘陵是否随气候周期而变化。 洋脊附近的新沉积物岩心将揭示热液活动是否也随冰川循环而变化，以及变化的程度。 对海底火山岩的取样和分析将显示地球内部的融化如何随时间而变化。 海上工作将在两次巡航中进行，一次在美国海洋调查船上，另一次与德国调查人员合作。 在陆地上，我们将与美国地质调查局的主要火山学家合作，调查喀斯喀特火山在最近冰川周期中的火山信号。 新测量的年龄将限制火山对冰川作用的反应时间。 地球化学分析将限制火山活动对冰川变化的反应，以及二氧化碳排放量的变化。 建模工作将研究冰盖和海平面的变化如何导致陆地和海底火山区下方的压力变化，并生成地球内部融化的定量模型以及它如何对海平面变化做出反应。 最终目标是建立一个综合模型，将火山活动、二氧化碳和气候联系起来，并测试它们在许多冰川循环的时间段内如何相互作用。 从本质上讲，我们正在探索地球内部与地球气候之间的耦合，也许会发现，即使是海底的结构也可能对气候变化做出反应，而气候变化最终是由我们星球接收的太阳能数量的变化引起的，冰川周期受到固体地球脉动的影响。