Quantifying Sampling Biases and Silicate-Derived Sr in Continental Runoff: A Coupled 87Sr/86Sr - 88Sr/86Sr Study

海水锶同位素（87 Sr/86 Sr）记录是重建效果最好的海洋同位素记录之一。它已被广泛用于估计大陆和热液输入海水的时间变化，并且时间变化与冰川期、造山期和重大岩浆事件相关。尽管这一令人印象深刻的记录，估计当今的海水中锶的质量平衡从根本上不同意，突出的挑战，解释海洋锶同位素record.This项目的目的是调查如何严重目前估计大陆径流进入海洋的偏见，以及如何可以纠正这种偏见。海洋记录的解释关键在于对当今物质平衡和强迫因素的公正理解。除了放射性物质（87 Sr/86 Sr）同位素组成，（88 Sr/86 Sr）同位素特征可能有助于了解硅酸盐与碳酸盐来源的锶的平衡，从而了解硅酸盐和碳酸盐风化之间的平衡。这项研究将在全球河流观测站的保护下进行，该观测站是一个合作组织，国际科学家和社区志愿者网络，旨在以时间序列方式观测河流系统。公民科学家和REU的学生将从事采样代表河流排水北美西海岸和东海岸。邀请当地学校参加“我的河，我的家”学生艺术项目。

The Strontium isotope (87Sr/86Sr) record of seawater is one of the best-reconstructed marine isotope records. It has been widely used to estimate temporal changes of continental and hydrothermal inputs to seawater, and temporal variations have been correlated with periods of glaciations, mountain building and major magmatic events. Despite this impressive record, estimates of the present-day mass balance of strontium in seawater fundamentally disagree, highlighting the challenges of interpreting the marine strontium isotope record.This project aims at investigating how severely present estimates of continental runoff into the ocean are biased, and how such biases can be corrected. The interpretation of the marine record critically hinges on an unbiased understanding of the present-day mass balance and forcing factors. In addition to the radiogenic (87Sr/86Sr) isotope composition, the stable (88Sr/86Sr) isotope signature may yield insights into the balance of silicate- vs carbonate-derived strontium, and thus the balance between silicate and carbonate weathering.The study will be conducted under the umbrella of the Global Rivers Observatory, a collaborative, international network of scientists and community volunteers aimed at observing river systems in time-series fashion. Citizen scientists and REU students will be engaged in sampling representative rivers draining the West and East coasts of North America. Local schools are invited to participate in the "My River, My Home" student art project.