YNP Mantle Plume
July 7 ” Discovery of a continuous magma system beneath Yellowstone from the mantle to the upper crust using new seismic imaging data and measurement of an unprecedented ground uplift by precise GPS measurements correlated with the largest Yellowstone earthquake in 40 years — linked dynamic Processes of the Yellowstone mantle plume-volcano system”
Presented by Dr. Robert Smith, Distinguished Research Professor of Geophysics, University of Utah.
Yellowstone is truly one of the world’s great volcanoes and has experienced 3 cataclysmic eruptions in last 2.1 million years resulting in what are sometimes called supervolcanos. Understanding this system is both intellectually interesting and scientifically important. Bob Smith has been studying the Yellowstone-Teton system for 55 years and along with colleagues Jamie Farrell, Hsin-Hua Huang, and Christine Puskas have studied the complexities and interactions of active geologic features of this giant volcano-tectonic using modern earthquake methods and GPS measurements. We will present new information about how the Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world and how an understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. We will explain how through the use of a joint local and teleseismic (global) earthquake P-wave seismic inversion process they have come to understand that a basaltic lower-crustal magma body provides a magmatic link between the Yellowstone mantle plume and the previously imaged upper-crustal magma reservoir. This lower-crustal magma body has a volume of 46,000 km3, ~4.5 times larger than the upper-crustal magma reservoir, and contains a melt fraction of ~2%. These estimates are critical to understanding the evolution of the Yellowstone-Snake River Plain bimodal basaltic-rhyolitic volcanism, and constraining dynamic models of the magmatic system for volcanic hazard assessment. In addition, Yellowstone experienced an unprecedented episode of very rapid ground uplift from late 2013 through early 2014, detected by precision GPS at Norris geyser basin. The uplift was accompanied by a 6-8 month episode of extended swarms around the Norris region and was capped by a M4.8 earthquake on March 30, 2014, which was the largest earthquake recorded in Yellowstone in 40 years. These phenomena reflect interactive stresses between volcano and tectonic processes that can effect dynamic interactions between the Yellowstone caldera and the Teton fault that can induce large volcano eruptions and large earthquakes.