CAREER: Investigating the unrest and eruption potential of caldera forming volcanoes in the Aleutians

点击翻译按钮获取中文摘要

Caldera-forming explosive volcanic eruptions that emplace tens to hundreds of cubic kilometers of ash and lava are among the most devastating natural hazards on Earth. The Aleutian Island Arc of North America has played host to more than 20 caldera-forming eruptions and currently has several active caldera volcanoes. While some Aleutian calderas have erupted 20 km3, many formed in large explosive events that emplaced 50-100 km3 of material. Impacts from these events were wide reaching. For example, the eruption of Aniakchak 3,400 years ago was associated with a regional tsunami and extensive ash dispersal across the arctic region. If such an eruption were to occur today it would pose a significant hazard not only to local communities but also to 50,000 airline passengers that fly over Alaska each day. Understanding the conditions that promote the development of catastrophic caldera forming eruptions is critical for evaluating eruption precursors and assessing hazards at volcanic systems in Alaska and worldwide. Working closely with collaborators at the Alaska Volcano Observatory, the aim of this research is to develop a forecasting method to monitor active volcanoes in the Aleutians and investigate the mechanisms that trigger their eruption. The broader impacts of this CAREER grant include investigation of efforts to improve recruitment and retention of students from underrepresented groups in the Earth sciences.Evaluating volcanic hazards requires a multidisciplinary approach that links monitoring data with dynamic models. This CAREER grant will support the development of volcano forecasting methods to monitor current unrest at Aleutian caldera systems and investigate previous eruptions to determine triggering mechanisms. Sequential data assimilation methods will be adapted to provide a multi-data stream model-data fusion forecasting framework. Specifically, geophysical observations of ground deformation and seismicity patterns will be combined with thermomechanical models to track the stress evolution of three active caldera systems in the Aleutians: Okmok, Westdahl, and Veniaminof. These systems have comparable sizes and eruptive products, but markedly different unrest and eruption histories. The researchers will utilize statistical data assimilation to take advantage of the extensive monitoring data sets available in the Aleutians to conduct a series of numerical experiments to investigate the relationship between magma chamber size, volume flux, and overpressurization, and how these parameters link to predictions of eruption size and frequency. Precursory signals will be investigated to better understand what mechanisms catalyze volcanic eruption. Model and data limitations will be analyzed to inform future investigations and data collection efforts. As the three target volcanoes have past records of caldera-forming eruptions, the researchers will investigate the potential for future caldera forming eruptions and the factors that impact the evolution of a volcano causing it to transition from frequent small eruptions to large catastrophic eruptions. The development of a data synthesis framework for handling the disparate datasets collected at active volcanic systems in the Aleutians will have broad community impact and transferability to monitoring volcanic unrest worldwide. In additional to investigating the mechanics of triggering volcanic eruptions, this work will provide the necessary first steps towards a community volcano-forecasting framework. Through the WIDER (Widening Implementation and Demonstration of Evidence Based Reforms) program the principal investigator will track cohorts of students over time to develop strategies that have a long-term effect on both recruitment and retention of women and minorities in the Earth sciences.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.