Shallow Active-Source Seismic Imaging of Old Faithful Geyser in the Upper Geyser Basin of Yellowstone National Park Using a Dense Seismic Array

Session: Recent Development in Ultra-Dense Seismic Arrays With Nodes and Distributed Acoustic Sensing (DAS) [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

The Upper Geyser Basin of Yellowstone National Park consists of active geysers which erupt hydrothermal water from a subsurface reservoir, the most famous of which is Old Faithful. To image the Old Faithful hydrothermal system, we process 2-D and 3-D active-source seismic data recorded in November 2016 using a densely spaced seismic array. Our 3-D array consists of 521 receivers and 343 shot locations. Our 2-D line trends SW-NE, centered on Old Faithful Geyser, with 39 receivers and 39 shot locations. Typically, ~5 shots were stacked at each location in order to increase signal to noise ratio. Both arrays have a station spacing of ~25m, but there is a ~100m gap in any direction from the Old Faithful Geyser orifice. The source in this experiment was a 12lb sledgehammer striking a metal plate. Our receivers are 3-component, 5-Hz Magseis Fairfield Z-Land seismometers. We pick refracted P-wave first arrivals and invert the picks to create a velocity model and tomographic profiles. We aim to visualize changes in lithology around Old Faithful geyser and the subsurface plumbing system in greater detail than previous studies. Preliminary results from the 2-D profile show slight differences from previous studies, with the P-wave refraction images allowing for more detailed interpretation. Creating tomographic profiles and depth-migrated shot gathers will contribute to scientific understanding of the Old Faithful hydrothermal reservoir beneath Old Faithful by allowing us to visualize in   2-D and 3-D the geometry and structure of the shallow hydrothermal conduits feeding the geyser.

Presenting Author: Jordan R. Caylor

Authors