Volcano Monitoring using InSAR: application to the Cascades Volcanoes

卫星大地测量学的最新发展通过对地震间应变积累和岩浆侵入等主要非地震过程的观察，为火山过程和大陆构造提供了新的视角。科学家们对这些测量感兴趣，因为它们可以确定控制大陆变形的机制，并量化控制流变学的本构定律，但实际应用包括地震和火山灾害评估以及地热资源。InSAR已被用于研究各种情况下的火山形变，但地面外观(如植被、陡坡)的变化降低了干涉测量的相干性，而对流层水蒸气引起的路径延迟的变化限制了精度。我们的研究小组是国家地球观测中心(NCEO)的一部分，已经开发出算法(多干涉图速率和时间序列估计器；称为PIRATE)，旨在测量与断层相关的过程，如类似条件下的地震间应变累积(Biggs等人，2007；Elliott等人，2008；Wang等人，2009)和震后松弛(Biggs等人，2009)。美国地质勘探局的喀斯喀兹火山观测站热衷于让我们改编这个代码和其他代码来研究火山变形。其目的将是将这些方法应用于其广泛的雷达数据档案，并建立一个对级联靶场进行近实时监测的业务系统。这个项目是真正的协作性的，大学将提供来自科学应用的算法开发，而CASE合作伙伴将提供对数据集的访问和结果的实际应用。合作伙伴将共同提供培训，从纯粹的科学算法开发到实际的危险监测。美国地质勘探局现有的数据档案和基础设施使其成为转移最新技术发展的理想环境，但该项目也将对全球和英国产生影响。世界各地的许多其他火山都处于类似的环境条件下，我们已经与其他几个天文台建立了联系，这些天文台将受益，英国保险业的全球利益也将受益。学生将接受广泛领域的培训，包括卫星大地测量学、图像分析、火山学和计算机。他们还将在准备和向学术和危险监测受众介绍他们的研究方面得到指导。在项目期间，学生将在CVO工作至少6个月，参与火山观测站的日常监测活动，并将InSAR观测纳入地面测量。这个项目需要有地球物理、物理、数学或工程方面的背景。完成后，学生将为在工业或学术界的职业生涯做好充分准备，包括在火山学、地球观测、风险和灾害管理以及保险等领域的研究。

Recent developments in satellite geodesy are providing a new perspective on volcanic processes and continental tectonics through observations of largely aseismic processes such as interseismic strain accumulation and magma intrusion. Scientists are interested in these measurements since they can identify the mechanisms controlling continental deformation and quantify the constitutive laws controlling rheology, but practical applications include seismic and volcano hazard assessment and geothermal resources. InSAR has been used to study volcanic deformation in a wide variety of situations but the interferometic coherence is reduced by changes in the appearance of the ground surface (e.g vegetation, steep slopes) and the accuracy is limited by variations in the path delays caused by tropospheric water vapour. Our research group, part of the National Centre for Earth Observation (NCEO) has developed algorithms (Poly-interferogram rate and time-series estimator; known as PIRATE) which are designed to measure fault-related processes such as interseismic strain accumulation (Biggs et al, 2007; Elliott et al, 2008; Wang et al, 2009) and postseismic relaxation (Biggs et al, 2009) in similar conditions (e.g. Alaska, Tibet). The USGS Cascades Volcano Observatory is keen for us to adapt this and other codes to study volcanic deformation. The aims will be to apply these methods to their extensive archive of radar data and set up an operational system for near real-time monitoring for the Cascades Range. This project is truly collaborative, the universities will provide the algorithm development from scientific applications while the CASE partner will provide access to the dataset and a practical application for the results. Together the partners will provide training which cuts across purely scientific algorithm development to practical hazard monitoring. The existing data archive and infrastructure of the USGS make this the ideal environment to transfer recent technological developments, yet the project will also have impact globally and to the UK. Numerous other volcanoes around the world sit in similar environmental conditions and we have established links with several other observatories who would benefit, as will the global-interests of the UK-insurance industry. The student will receive training in a wide range of areas, including satellite geodesy, image analysis, volcanology and computing. They will also receive guidance in the preparation and presentation of their research to both academic and hazard monitoring audiences. During the project the student will spend at least 6 months based at CVO, participating in the day-to-day monitoring activities of the volcano observatory and incorporating the InSAR observations into ground-based measurements. A background in geophysics, physics, mathematics or engineering is required for this project. Upon completion, the student will be very well prepared for a career in industry or academia, including research in topics as diverse as volcanology, earth observation, risk and hazard management and insurance.