Near-Surface Geophysical Insights into Geyser Structure and Dynamics, Yellowstone National Park, WY

Hydrothermal geysers are visually engaging geomorphic features that represent a rapid and occasionally violent release of energy manifested as hydrothermal fluids/vapors launched skyward. Although not completely rare worldwide, hydrothermal geysers intrigue humans now and throughout history. Fortunately for us, Yellowstone National Park is home to roughly 500 geysers, making it the most concentrated geyser field in the world. Yet, the dynamics of geyser eruptions are uncertain. Much of this uncertainty stems from a lack of knowledge of their subsurface structure. So fundamentally, we must ask questions about what the “plumbing” looks like before we study how it functions? Geophysical imaging provides an opportunity to image these structures as well as observe parts of the dynamic geyser behavior. To start, we will discuss various active geophysical methods to (1) constrain the characteristics of the structure and (2) better understand the subsurface geometry of Spouter & Old Faithful Geyser (Yellowstone National Park) and their “hydrothermal geyser reservoir” structures. After establishing the structure, we will explore how geophysical data informs geyser dynamic models for Upper Geyser Basin, YNP. Again, we apply active, time-lapse electrical (ERT & SP) and electromagnetic (TEM) geophysical methods, sensitive to the subsurface electrical resistivity properties, to track hydrothermal fluid and vapor through a geyser system at Spouter Geyser and Old Faithful, Yellowstone National Park.