Collaborative Research: Suspended particle geochemistry along the US GEOTRACES Eastern Pacific Zonal Transect, from high productivity ocean margin to deep sea hydrothermal plume

在2013年GEOTRACES东太平洋巡航期间，将会遇到各种各样的海洋环境，从秘鲁附近的高生产力/高颗粒通量水域，到秘鲁-智利氧气最低地带，东太平洋隆起的热液羽流，最后到塔希提岛周围的一些营养最少的水域。来自罗格斯大学和伍兹霍尔海洋研究所的科学家将从同一个Go-Flo瓶中采样悬浮颗粒物，该瓶将用于在整个样带上采样溶解的痕量金属及其同位素(TEI)。悬浮物样品将分析42种元素，包括颗粒活性稀土元素。此外，每个水柱采样站将采集岩心顶部沉积物，并分析悬浮粒子中的整体成分(即有机碳、蛋白石、生物碳酸盐和成岩成分的相对百分比)和相同的42种元素。这项研究的结果将被用来评估悬浮颗粒在东太平洋TEI生物地球化学循环中的作用，方法是解决三组关键问题：(1)TEI被浮游植物和上层海洋中的非生物颗粒吸收是如何推动悬浮颗粒成分通过更深的水柱，沿着从高生产力的秘鲁边缘到营养稀少的海洋内陆的巨大梯度？(2)上层海洋的横向变化如何传递到沉积物(古)记录？(3)在秘鲁-智利OMZ观察到的溶解和颗粒TEI的分布中，垂直循环和横向平流的相对影响是什么？(4)在岩心-顶部沉积物中是否有保存下来的OMZ活动的特征特征？(5)是什么主导了热液羽流中自生颗粒对TEI的吸收，这些过程在多大程度上被核心-顶部沉积物的持续吸收所增强？在更广泛的影响方面，这位来自罗格斯大学的科学家正在与海洋科学教育卓越网络世界中心(COSEE-NOW)的教育主任合作，通过邀请教师和高中生参加关于气候和海洋科学的研讨会和演讲，为MARE(海洋活动、资源和教育)计划做出贡献。在COSEE-NOW的帮助下，他还计划在太平洋邮轮和随后的实验室分析工作期间制作教育视频剪辑，教育他们如何使用地球化学来了解海洋是如何运作的。两位科学家还计划为这位罗格斯大学的科学家讲授的海洋学入门课程开发一个名为“粒子、金属和碳”的教学模块。罗格斯大学的一名博士后将作为该项目的一部分得到支持和培训。

During the 2013 GEOTRACES Eastern Pacific cruise a diverse range of oceanic environments will be encountered from the high productivity/high particle flux waters off Peru to the Peru-Chile oxygen minimum zone, the hydrothermal plume of the East Pacific Rise, and finally to some of the most oligotrophic waters around Tahiti. Scientists from Rutgers University and Woods Hole Oceanographic Institution will sample suspended particulates from the same GO-Flo bottles that will be used to sample dissolved trace metals and their isotopes (TEIs) across this entire transect. The suspended matter samples will be analyzed for 42 elements, including the particle-reactive rare earth elements. In addition, core-top sediments will be collected at every water-column sampling station and analyzed for both bulk composition (i.e., relative % content of organic carbon, opal, biogenic carbonate and lithogenic components) and the same 42 elements to be analyzed in the suspended particulates. Results from this study will be used to assess the role of suspended particulates in the biogeochemical cycling of TEIs across the Eastern Pacific by addressing three key sets of questions: (1) How does uptake of TEIs into phytoplankton and non-living particles in the upper ocean drive the suspended particulate composition through the deeper water column, along the substantial gradient from the high productivity Peru margin to the oligotrophic ocean interior?; (2) How faithfully is the along-transect variability in the upper ocean transmitted to the sediment (paleo) record?; (3) What are the relative influences of vertical recycling versus lateral advection in generating the distributions of dissolved and particulate TEIs observed in the Peru-Chile OMZ?; (4) Is there a characteristic signature of OMZ activity that is preserved in core-top sediments?; (5) What dominates TEI uptake onto/into authigenic particles in hydrothermal plumes and to what extent are these processes augmented by continuing uptake in core-top sediments?; and (6) What is the net effect from submarine venting on global TEI budgets?As regards broader impacts, the scientist from Rutgers University is collaborating with the Education Director of the Centers for Ocean Science Education Excellence Networked Ocean World (COSEE-NOW) to contribute to the MARE (Marine Activities, Resources, and Education) program by inviting teachers and high school students to workshops and presentations on climate and ocean sciences. With the help of COSEE-NOW, he also plans to create educational video clips during the Pacific cruise and the subsequent laboratory based analytical work to educate them on the use of geochemistry to understand how the ocean works. Both scientists also plan to develop a teaching module entitled "Particles, Metals, and Carbon" for an Introduction to Oceanography class taught by the Rutgers scientist. One postdoc from Rutgers University would be supported and trained as part of this project.