Investigation of Earthquake and Geyser Activity From Short-Term Nodal Array Deployment Centered at Old Faithful Geyser

摘要

Yellowstone National Park is home to an active caldera, centrally located on the North American continent. Several studies have concluded the existence of a hotspot that fuels the hydrothermal, geothermal and earthquake activity in the Yellowstone region. The geologic record of Yellowstone contains multiple layers of volcanic deposits that indicate the region experienced three previous massive volcanic eruptions dating back 2.05Mya, 1.2Mya and the most recent 640,000 years ago. Yellowstone is also home to one of the largest geothermal areas in the world. With this study, an in-depth look at seismicity and geyser events recorded within an active geothermal region, specifically, the Upper Geyser Basin that includes the Old Faithful Geyser (OFG) will provide a new perspective of the immediate subsurface. A temporary deployment of a three-dimensional array of 133 Z-Land Nodal geophones recorded passive data in the OFG area from November 2--14, 2015. The deployment occurred as a joint venture with the University of Utah, in which they focused their study on processing ambient noise and seismic recordings of the hydrothermal activity with the same dataset. Our analysis of the data will focus on the regional and teleseismic earthquakes as well as some of the geyser eruption events as picked up by the array. The constant activity of Yellowstone region provides frequent seismic sources, which could provide useful information for seismic interpretation of the complex subsurface.;One of the objectives of this study included signal processing of local micro-seismic events and teleseismic events. Spectral images, Fast Fourier Transform (FFT), phase and amplitude, analysis are examined for a variety of recorded seismic and geyser events. We also created ground motion visualizations from seismic and geyser events. These visualizations show the propagation of waves within the Upper Geyser Basin as they travel through the array.