Join us for Volcano Views & Brews lecture series with the Mt St Helens Institute!
What’s Brewing at Yellowstone?
with Dan Dzurisin of USGS Cascades Volcano Observatory and Yellowstone Volcano Observatory
Presentation begins at 6:30 p.m. - Join us anytime after 5:00 p.m. for food and drink. $5 suggested donation.
A big thank you to our friends and sponsors at Sportsman's Warehouse(Vancouver), Sportsman's Warehouse (Portland), Sportsman's Warehouse (Kelso) and Sportsman's Warehouse (Hillsboro).
Yellowstone often makes the news as a “supervolcano” threatening to unleash a global catastrophe that will end civilization as we know it. The real story, it turns out, is slightly more nuanced. It’s true that Yellowstone is among the most dynamic caldera systems on Earth, and it has produced some of the largest eruptions knownlarge enough to make a considerable dent in modern civilization if one were to occur today. But it’s important to keep in mind the timescale of those eruptions when assessing the hazard. The most recent “super eruption” at Yellowstone occurred 640,000 years ago and the youngest lava flow in the caldera is about 70,000 years old. There have been some large hydrothermal explosions during Holocene time, but even those events occurred several thousand years ago. What’s happening today at Yellowstone and will likely continue for the foreseeable future is what happens between eruptions: lots of small earthquakes, spectacular hydrothermal activity, and (most interesting of all) plenty of ground deformation. Our understanding of the latter topic spans almost a century, beginning with the first geodetic leveling survey at Yellowstone in 1923. A repeat survey during 19751977, following the magnitude 7.5 Hebgen Lake earthquake in 1959 and in response to the magnitude 6.1 Yellowstone Park earthquake in June 1975, yielded the surprising result that the central part of the caldera had risen more than 70 cm, at an average rate of 14 mm/yr. Thus began an investigation of Yellowstone’s ground movements that has evolved to include a state-of-the-art continuous GPS network and periodic radar scans of the region from Earth orbiting satellites. The story that’s emerging is one of nearly continuous but changing movements attributed to several interconnected sources, including Yellowstone’s deep magmatic roots, crustal magma reservoirs, and restive hydrothermal system. As I write this, the floor of Yellowstone caldera is going up and the north rim area is going down. Stay tuned for further developments.
Dan Dzurisin's Bio
Dzurisin is a staff member at the USGS Cascades Volcano Observatory in Vancouver, Washington. His research specialty is volcano geodesy—the science of how and why volcanoes deform in response to magmatic, tectonic, and hydrothermal processes occurring beneath them. Dzurisin uses various geodetic techniques, including leveling, GPS, and radar interferometry (InSAR) to study volcano deformation in the Cascade Range, Aleutian volcanic arc, Hawaii, and Yellowstone. He is an author of more than 100 scientific publications, including the book Volcano Deformation: Geodetic Monitoring Techniques, published by Springer-Praxis in 2007.