Collaborative Research: Constraining Heat Flux from the Shallow Geothermal System, Yellowstone Caldera, Wyoming

在过去的50年里，人们一直在以不同的方式估算黄石火山系统的热通量。 了解黄石的地热通量有很多重要的原因：热量和质量通量是决定火山喷发潜力的重要部分，有人认为热通量或热盐水迁移的变化可能与火山口底部的膨胀/收缩或大地震事件有关。 更基本的是，地表的热通量由进入系统底部的热量控制。 黄石火山口的整体活跃热预算已估计在过去使用氯质量平衡在春季排放。 该方法受假设和不确定性的影响。 本项目将探索一种新方法的可行性，以推断黄石温泉的质量和能量通量。 该团队将使用泉水和大气温度的互相关，以估计泉水流量（质量通量）和流入泉水温度（因此焓通量）。 对平流质量和能量通量的估计（使用时间序列方法）与泉水之间的扩散能通量相结合，将使他们能够全面描述浅层地下与大气之间的质量和能量通量，本项目获得的数据将用于改进对黄石火山口浅层热液系统的热量和质量通量的估计。 有待开发的方法将为今后热液系统的热量和质量平衡研究确定一个模板。 预计本研究中采用的方法和项目过程中收集的数据将对火山灾害评估很重要，并有助于公众教育和享受黄石公园和其他国家资源。 也有可能通过卫星遥测来采用这里所开发的评估热液泉的热量和质量通量的时间序列方法。 研究生和本科生将参与研究，他们在这个项目中的培训将为他们提供职业发展的机会。 他们将做好充分准备，以周到的解决方案面对社会未来的挑战。

Estimating the heat flux from the Yellowstone volcanic system has been pursued in different ways over the past 50 years. Understanding the geothermal flux from Yellowstone is important for many reasons: heat and mass flux are an important part of determining the volcano's eruptive potential, and it has been suggested that changes in heat flux or hot brine migration may be correlated with inflation/deflation of the caldera floor or large seismic events. More fundamentally, the heat flux at the land surface is controlled by the quantity of heat entering the bottom of the system. The overall active heat budget of the Yellowstone caldera has been estimated in the past using chloride mass balance in spring discharges. This method is subject to assumptions and uncertainties. This project will explore the feasibility of a new method to infer mass and energy fluxes for Yellowstone hot springs. The team will use cross-correlation of spring and atmospheric temperatures that allow estimates for spring discharge (mass flux) and the inflow spring temperature (and hence enthalpy flux). Estimates of the advective mass and energy flux (using a time-series method) combined with the diffusive energy flux between springs will allow them to derive a comprehensive description of mass and energy fluxes between the shallow subsurface and the atmosphere.The data to be obtained in this project will be used to improve estimates of heat and mass flux for the shallow hydrothermal system in the Yellowstone caldera. The methods that to be developed will define a template for future heat and mass balance studies of hydrothermal systems. It is expected that the methods to be employed in this study and the data to be gathered in the course of this project will be important to volcanic hazard assessment, as well as contributing to public education and enjoyment of Yellowstone and other national resources. It is also possible that the time-series method of evaluating heat and mass flux of hydrothermal springs as developed here could be approached via satellite-based telemetry. Graduate and undergraduate students will be involved in the research and their training in this project will provide them with career-building opportunities. They will be well prepared to face societies future challenges with thoughtful solutions.