Hotstuff Seminar - Professor Matt Pritchard - Cornell University. Title: Lessons learned from combining satellite deformation, degassing and thermal observations of volcanoes: Latin America and global perspectives
Professor Matt Pritchard, Cornell University
Room G8, School of Earth Sciences, Wills Memorial Building
We are pleased to welcome Professor Matt Pritchard from Cornell University, who will be delivering this week's Hotstuff seminar:-
Title: Lessons learned from combining satellite deformation, degassing and thermal observations of volcanoes: Latin America and global perspectives
Volcanic eruptions pose a risk to the 800 million people estimated to live within 100 km of potentially active volcanoes, and can have a global impact by disrupting the climate and economy. Unfortunately, about half of these volcanoes have no ground-based monitoring while others have only a few instruments that provide insufficient information.
In this talk, I will describe two efforts to assess the extent to which remote sensing observations can help to fill in the gaps. In the first project, we compare available databases of global, satellite-detections of ground deformation (1992–2016), SO2 emissions (1978–2016), and thermal features (2000–2016) that together include 306 volcanoes. Each database has limitations in terms of spatial and temporal resolution but each technique contributed 45–86 unique detections of activity that were not detected by other techniques. Integration of these three databases shows that satellites detected ~10^2 volcanic activities per year before the year 2000 and ~10^3 activities per year after the year 2000.
From 1978 to 2016 we conduct a preliminary analysis of the timing between the onset of satellite-detections of deformation (N = 154 episodes, N = 71 volcanoes), thermal features (N = 16,544 episodes, N = 99 volcanoes), and SO2 emissions (N = 1495 episodes, N = 116 volcanoes) to eruption start dates. We find that deformation is dominantly pre-eruptive (47% and 57%) whereas available databases of thermal features and SO2 emissions utilizing mainly low-resolution sensors are dominantly co-eruptive (88% and 76% for thermal features, 97% and 96% for SO2 emissions).
In the second project, we use satellite observations to generate times series of degassing, thermal anomalies, and surface deformation spanning 17 years at 47 of the most active volcanoes in Latin America. We test the classification of these volcanoes as open or closed volcanic systems and find that ~28% of the volcanoes do not fall into either classification -- the rest show elements of both, demonstrating a dynamic range of behavior that can change over time. We test the applicability of different conceptual models to describe these time series -- such as the intrusion of new magma in a reservoir, magma evolution during storage, magma withdrawal, volatile transport, changes in tectonic stress, etc. We find that the majority (44) of the volcanoes fall into 8 groups of "volcano type." These groups ranged from as simple as persistently erupting, to more complex, such as magma evolution, and/or volatile transport transitioning to magma intrusion or transitions between open and closed systems. We also identified similarities in activity among multiple volcanoes, which provides a framework for relating unrest and eruption style. Applying observations from similar volcanoes can help to interpret monitoring data and better forecast eruptions.
All staff and students welcome.
For further information, please contact Damaris Butters.