EAGER:Field Testing Two New Portable Geothermal Gradient Probe Prototypes

在过去60年左右的时间里，科学家们一直在使用大型重型仪器从海底收集热流数据，这些仪器被插入沉积物中，测量温度与海底以下深度的关系。热流数据提供了在海底附近和海底以下发生的物理、化学和生物过程的基本信息，并最终提供了关于地球热和化学演化的信息。本研究的目标是推进两个原型热探头的开发，使其超越测试/开发阶段，以便它们可以被广泛的科学界使用。新的热流探测器将更轻，并提供近实时的温度数据；这两种方法都将简化目前收集热流数据的方式。与传统热流探头相比，该项目将新技术融入到原型中。该项目包括国际合作，并为本科生提供培训。该项目旨在以更高的采样率和比标准热流探头更长的耐用时间提供实时或近实时的温度数据。这些原型有可能改变我们对断层、渗漏、喷口或火山口湖附近复杂海底流体流动的理解。这两个原型探头的设计工作水深为500米（原型-1）和2000米（原型-2）；每个探头的单独组件都经过了压力测试。然而，目前，完整构建的探头尚未在大于1兆帕（100米水深）的压力下进行测试。原型-1的设计包括实时热流数据和海底成像，用于现场表征和选择；原型机2采用蓝牙数据传输。与传统方法相比，这两种原型都将使热流数据收集增加两倍。然而，在压力测试和地热梯度场测试完成之前，这些探测器无法在没有高故障风险的情况下安排用于科学用途。这项研究有可能改变海洋热流和流体通量的收集和分析方式，特别是在高热流环境中。工作包括2号原型机的全压力测试和潜在热梯度测试。具体来说，压力测试将达到20兆帕（水深达2000米），热敏电阻将在蒙特塞拉特近海进行测试。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

For the past sixty years or so, scientists have been collecting heat flow data from the seafloor using large, heavy instruments that are inserted into the sediment and measure temperature versus depth below the seafloor. Heat flow data provide fundamental information on the physical, chemical and biological processes that are occurring near and below the seafloor and ultimately, information on the thermal and chemical evolution of Earth. The goal of this study is to advance the development of two prototype heat probes beyond the testing/development stage so that they can be used by the broad scientific community. The new heat-flow probes will be lighter and provide near-real-time temperature data; both of which will streamline how heat flow data currently are collected. The project incorporates new technology into the prototypes compared to conventional heat flow probes. The project includes international collaboration and provides training for an undergraduate student.This project aims to provide either real-time or near-real time temperature data at higher sample rates and with longer endurance time than standard heat flow probes. The prototypes have the potential to transform our understanding of complex submarine fluid flow near faults, seeps, vent sites, or caldera lakes. The two prototype probes are designed to operate in water depths of 500 m (Prototype-1) and 2000 m (Prototype-2); individual components for each probe have been pressure tested. Currently, however, the fully constructed probes are untested at pressures greater than 1 MPa (100 m water depth). Prototype-1 is designed to include real-time heat flow data and sea-bottom imaging for site characterization and selection; Prototype-2 is designed with Bluetooth data transmission. Both prototypes will increase heat flow data collection by a factor of two compared to conventional methods. Until pressure tests and geothermal gradient field tests are completed, however, the probes cannot be scheduled for scientific use without high risk of failure. This study has the potential to transform how marine heat flow and fluid fluxes are collected and analyzed, especially in high heat flow environments. Work involves full pressure testing and potential thermal gradient testing for prototype-2. Specifically, the pressure tests will go to 20 MPa (up to 2000 m water depth), and the thermistors will be tested offshore Montserrat.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.