Nov 2023
Abstract
Active tectonics controls many of the key elements of world we live on including the modern climate, location of mountains, earthquakes, ore systems and associated geothermal targets and volcanoes. Through the geological and geophysical characterisation of neotectonic (or young tectonics) systems we can understand the correlation between active volcanoes, earthquakes, and faults, as can be seen from a couple of recent case studies from Chilean Patagonia as well as the recent eruptions (2021 to present) in Southwestern Iceland. Using a wide suite of geophysical and geological methods we can see the correlation between active faults and volcanism. In addition to the larger scale tectonic system, through detailed analysis of active faults we can better understand both seismic and fault rupture hazards. Proper charactersiation of these systems can help us better understand regional and local seismic hazard throughout the seismic cycle, in particular to seismic source characterisation, which focuses on questions including: how big can the earthquakes be along a fault zone (either in terms of energy released or in terms of local peak strong ground motions)? and how often do these faults generate earthquakes? Additionally, understanding where faults occur and the nature of these faults can help us with fault rupture characteristics which are important for critical infrastructure planning and linear infrastructure planning (e.g. fault pipelines). Engineering solutions for these geological hazards will be touched upon based on real world examples including the Mw 7.9 Denali Earthquake in Alaska and 2015's Mw 8.4 Illapel Earthquake in central Chile.
Bio
Dr. Gregory De Pascale is an Associate Professor at the University of Iceland's School of Engineering and Natural Sciences, and a member of the Earth Institute of Iceland and works on neotectonics, active faults, earthquake geology, and seismic hazard. His students and colleagues work in the natural laboratory, in the field, with main focus areas in the Andes of Chile, Peru, and Argentina, Iceland, the Southern Alps of New Zealand, the East African Rift, and in Central Asia. They also keep a keen eye on happenings in North America (He formerly worked for Fugro and William Lettis and Associates, WLA on seismic and geohazard consulting globally). He did his PhD on the Neotectonics and Seismic Hazard of the Alpine Fault in New Zealand at the University of Canterbury (New Zealand) and did his Undergraduate and Masters degree at McGill University in Montreal, Canada and worked as an Assistant Professor at the University of Chile (UChile) in the Faculty of Engineering (FCFM) for 8 years prior to moving to Iceland in 2022. He and his research team (including postgraduate students) use classic field techniques mixed with modern and ever-improving technology including lidar and structure from motion (SfM) drone photography in addition to subsurface and submarine geophysics (e.g. multi beam sonar and sub-bottom profiling), classic structural and engineering geology methods, and Quaternary dating to explore, characterise and model active faults and neotectonics, with an affinity (when onshore) for humid climates (think rainforest) but operate globally. At the University of Iceland (and previously when he was based at the University of Chile), he teaches undergraduate courses on Structural Geology and Tectonics, and Field Geology and a postgraduate courses on modern remote sensing for field geology (e.g. drones and lidar) and Neotectonics and provides consulting insight on geological and seismic hazards on critical infrastructure projects worldwide.