RAPID: Deployment of a Field Rheometer Prototype

该项目为冰岛Geldingadalir火山再次喷发部署了现场流变仪原型，目的是测试其现场性能，并收集有关现场活动的冰岛大洋中脊玄武岩(MORB)的首次流变学数据。由于喷发的时间和发生的不可预测的性质，获取活跃的熔岩流是具有挑战性的。这场始于2022年8月3日的喷发，提供了无与伦比的进入活跃熔岩流的便利条件，这些活动熔岩流的性质足够“良好”，有助于就地测量熔岩性质。该项目致力于实现两个基本目标：1)前往冰岛部署现场流变仪原型，收集该设备的第一批现场测量数据，并测试其极限。2)在Geldingadalir火山测量熔岩的温度、剪切速率和fO2的情况下，进行了一系列两相(熔体+晶体)实验。总而言之，这使得该团队能够收集冰岛MORB熔岩流变学的第一批现场测量数据，并通过对比现场测量数据(有气泡)和实验室测量数据(无气泡)来推断气泡对三相流变学的影响。冰岛气象局公布的InSAR数据表明，这次喷发的岩浆涌入率高于2021年的喷发。这可能意味着火山喷发的持续时间比2021年更长，也可能意味着大部分可利用的熔岩是通过上一次喷发事件在短时间内形成的通道喷发出来的。对熔岩流动路径和推进速率的准确预测对于在喷发事件之前和期间的灾害缓解、民事保护和持续爆发的危机的管理至关重要。这项任务在很大程度上受到了对多相(熔体+晶体+气泡)熔岩流变学的不完全了解的阻碍。现场粘度测量极其罕见，而且主要局限于狭窄的成分范围(主要是夏威夷玄武岩)。这突显了对更广泛的成分进行更多、更好的现场测量的迫切需要。虽然我们对熔岩流动特性的了解在过去二三十年里有了很大的进步，但两个核心限制始终存在：1)准确地再现自然就位条件(规模、纹理、fO2)2)无法在实验室中保持三相悬浮(气泡在实验时间尺度上逸出，仅限于测量两相晶体-熔融悬浮)。在野外测量熔岩的粘度就消除了这两个限制。重要的是，当与无气泡的实验室测量相结合时，它有可能量化气泡对多相熔岩流变性的影响。因此，这个项目有可能解决一些主要的限制因素，以促进我们几十年来对熔岩流侵位的理解。结果将与科学界内外的利益攸关方分享，这项工作的一些样本和工具将被带入布法罗科学博物馆。该项目的洞察力也将被纳入到UB接地计划的动手练习中，为K12教育工作者提供内容。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project deploys a field rheometer prototype to the reawakened eruption at Geldingadalir Volcano, Iceland with the goal to test its field performance and to gather the first ever rheological data on active Icelandic Mid Ocean Ridge Basalts (MORB) in the field. Access to active lava flows is challenging due to the unpredictable nature of the timing and occurrence of effusive eruptions. This eruption, which started August 3, 2022, provides unparalleled ease of access to active lava flows whose nature is sufficiently “well behaved” to facilitate in-situ measurements of lava properties. This project strives to achieve two fundamental goals: 1) Travel to Iceland to deploy the field rheometer prototype to collect the first field measurements with this device and test its limits. 2) Performing a series of two-phase (melt+crystals) experiments at the temperatures, shear rates, and fO2 of lava measured at Geldingadalir Volcano. Combined, this enables this team to collect the first field measurements of the rheology of Icelandic MORB lavas and to deduce the effect of bubbles on three-phase rheology by contrasting the field measurements (with bubbles) and lab measurements (bubble-free). InSAR data published by the Icelandic Meteorological Office suggest higher magma influx rates for this eruption than for the 2021 eruption. This could mean either that the eruption lasts longer than that of 2021 or it could mean that much of the available lava is erupted through the pathway created during the previous eruptive event over a short period of time. Accurate forecasting of lava flow paths and advance rates is crucial to hazard mitigation ahead of and during effusive events, civil protection, and management of ongoing eruptive crises. This task has been hampered largely by an incomplete understanding of multiphase (melt+crystals+bubbles) lava rheology. Field viscosity measurements are extremely rare and largely limited to a narrow compositional range (dominated by Hawaiian Basalts). This highlights the dire need for more, and better in-situ measurements on a broader range of compositions. While our understanding of the flow properties of lavas has advanced significantly over the past two to three decades, two core limitations have always remained: 1) Accurate reproduction of natural emplacement conditions (scale, textures, fO2) 2) The inability to maintain three-phase suspensions in the lab (bubbles escape on experimental timescale, limiting measurements to two-phase crystals-melt suspensions). Measuring the viscosity of lava in the field removes both limitations. Importantly, when combined with bubble free lab measurements it has the potential to quantify the effect of bubbles on multiphase lava rheology. This project therefore has the potential to address some of the major limiting factors to advancing our understanding of lava flow emplacement for decades. Results will be shared with stakeholders within and beyond the scientific community, and some samples and tools from this work will be incorportated into the Buffalo Museum of Science. Project insights will also be incorporated into hands on exercises in the UB EarthEd program, providing content for K12 educators.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.