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

在过去的50年里，人们用不同的方法对黄石火山系统的热通量进行了估算。了解黄石公园的地热通量很重要，原因有很多：热量和质量通量是确定火山喷发潜力的重要组成部分，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。更根本的是，地表的热通量是由进入系统底部的热量控制的。黄石火山口的总体活跃热收支在过去已经用春季排放物中的氯化物质量平衡来估计。这种方法受假设和不确定性的影响。该项目将探索一种推断黄石温泉质量和能量通量的新方法的可行性。研究小组将利用泉水和大气温度的相互关系来估计泉水流量（质量通量）和流入泉水的温度（由此得出焓通量）。对平流质量和能量通量的估计（使用时间序列方法）与弹簧之间的扩散能量通量相结合，将使他们能够全面描述浅层地下和大气之间的质量和能量通量。在这个项目中获得的数据将用于改善黄石火山口浅层热液系统的热量和质量通量的估计。待开发的方法将为未来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在该项目过程中收集的数据将对火山危害评估具有重要意义，并有助于公众教育和享受黄石公园和其他国家资源。也有可能通过基于卫星的遥测技术来采用本文所开发的热液泉的热量和质量通量的时间序列评价方法。研究生和本科生将参与研究，他们在这个项目中的训练将为他们提供职业发展的机会。他们将做好充分准备，以深思熟虑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.