Degassing During a Seafloor Eruption along the Mid-Ocean Ridge: Helium, Argon and Carbon Isotopes in Basalts from the East Pacific Rise Integrated Study Site

几乎所有洋中脊玄武岩岩浆在穿过海洋地壳上升的过程中都会失去气体，因为它们含有饱和或过饱和的二氧化碳。数量不详的二氧化碳通过热液系统排出，并通过生化反应被居住在其中的生物利用。这项研究测量了1991-1992年和2005-2006年在东太平洋隆起RIDGE 2000综合研究基地喷发的玄武岩熔岩气泡中捕获的稀有气体（氩和氦）和二氧化碳浓度。这些气体的浓度和同位素组成提供了基本信息，可用于确定中洋脊上熔岩脱气的数量，并提供了对海洋地壳岩浆演化的见解。沿着单个熔岩流的长度对样本进行分析，提供了一个前所未有的机会，可以研究大洋中脊的岩浆补给，量化喷发前和喷发时发生的脱气量，并评估地球内部的碳在多大程度上被纳入热液流体并最终进入海底生态系统。这项工作的更广泛影响包括支持俄勒冈州立大学的一个新的稀有气体设施，并培训学生。

Virtually all mid-ocean ridge basalt magmas lose gas as they rise through the ocean crust because they are saturated or oversaturated with carbon dioxide. An unknown amount of the CO2 that is lost is vented through hydrothermal systems and used by organisms inhabiting them via biochemical reactions. This research measures noble gas (Argon and Helium) and CO2 concentrations trapped in bubbles of basaltic lavas erupted from 1991-1992 and 2005-2006 at the RIDGE 2000 Integrated Study Site on the East Pacific Rise. The concentration and isotopic composition of these gases provide fundamental information that can be used to determine the amount of lava degassing on mid-ocean ridges and provide insights into the evolution of magmas in the ocean crust. Analyses of samples along the length of individual lava flows offer an unprecedented opportunity to study magma recharge at a mid-ocean ridge, quantify the amount of pre-eruptive and syn-eruptive degassing that has occurred, and evaluate the extent to which carbon from Earth's interior is incorporated into hydrothermal fluids and ultimately into seafloor ecosystems. Broader impacts of the work include support of a new noble gas facility at Oregon State University and trains students.