HOW IS YELLOWSTONE CALDERA’S HYDROTHERMAL SYSTEM AFFECTED BY CHANGES IN MAGMA CHAMBER TEMPERATURE AND PRECIPITATION?

Yellowstone Caldera (YC), USA, is an area of geothermal activity fueled by a volcanic hotspot. This study aims to analyze the impacts of climate change, specifically changes in precipitation, on the hydrothermal system. I do this in three ways: (1) understanding the relationship between precipitation and geyser eruptions, (2) creating and analyzing land surface temperature (LST) imagery through Google Earth Engine (GEE) and (3) thermal modeling of the YC.

Precipitation data from NOAA shows that annual average precipitation has increased by 1.41 inches over the last century. Geyser eruption event data were collected from geysertimes.org, a publicly sourced database. Initial comparisons indicate no consistent correlations between precipitation and geyser activity at YC. I also compared YC to two other calderas, Valles Caldera (VC) in New Mexico and Long Valley Caldera (LVC) in California, which both were more geothermally active in the past. Data from NOAA show that the yearly average precipitation near VC decreased by 0.79 inches over the last century, whereas LVC has seen little change. This contrasts sharply with YC’s increasing trend.

To better assess other factors playing a role in geyser activity, I gathered data through GEE to compare it to precipitation data, explicitly looking at Norris Geyser Basin (NGB); from 2013 to 2014, the average LST cooled by at least 3ºC. There is a stronger correlation between increased LST and frequency of geyser eruptions, where high precipitation does not affect LST. This suggests there must be a third factor, possibly due to low rock porosity. To model this correlation, I used a 2D, temperature-dependent thermal model to determine whether there is a delayed relationship between precipitation increase and the temperature of the magma chamber. The variables included porosity, density, heat capacity, and thermal conductivity. I propose that greater water content will cause greater cooling of the magma chamber.