Caldera chronicles: The complex plumbing systems of Steamboat Geyser and Cistern Spring | National News

Yellowstone Caldera Chronicles is a weekly column written by scientists and staff at the Yellowstone Volcano Observatory. This week’s contribution comes from Sin-Mei Wu, Jamie Farrell, and Fan-Chi Lin, seismologists at the University of Utah Seismograph Stations and the Department of Geology and Geophysics.

With all eyes on the spectacular eruptions of Steamboat Geyser, it’s easy to lose sight of the fact that Cistern Spring, about 300 feet away, is gradually draining a few hours after the amazing water show at Steamboat.

In the 24 hours after the Steamboat eruption, Cistern Spring empties, only to refill and restore normal water levels within a few days. This pattern has been around since the 1960s and continues into Steamboat’s current active phase, which began in March 2018.

Indeed, it is not uncommon for individual hydrothermal features to be related in time. A good example is the Beehive Geyser near Old Faithful in the Upper Geyser Basin. Spectacular beehive outbreaks always occur a few minutes after activity on a smaller adjacent “indicator” vent.

It is believed that these types of compounds are a reason for the regularity of some eruptions, as the hydrothermal features underground can compete for water and heat resources. However, in most cases, features that appear to be related, such as the beehive geyser and the beehive indicator, are right next to each other (often within about 3 meters). In contrast, Steamboat Geyser and Cistern Spring are a lot further apart – about 100 meters.

This raises questions about the underground aqueduct. How are steamboat and cistern connected? And does the sanitary geometry influence the eruption dynamics and regularity of the Steamboat Geyser?

To seek answers to these questions, the University of Utah, in partnership with Yellowstone National Park, installed seismic arrays around Steamboat Geysers and Cistern Spring Seismic Arrays in the summer of 2018 and 2019, providing a non-disruptive way to determine the seismic source passing through Bubble formation and collapse occurs when the system is charged. This can enable four-dimensional views of the subterranean hydrothermal plumbing system.

The work recently published in the Journal of Geophysical Research found that the installation structures of steamboat and cisterns extend to a depth of at least 140 meters, which is much more than what was previously found at Old Faithful (about 260 feet or more) 80 meters). The pipe of the steamship is approximately vertically up to 120 meters deep.

Surprisingly, the cistern pipeline contains a shallow vertical conduit connected to a deep, large, and offset reservoir about 60 meters southeast of the source. Even more interesting is that there is no direct connection between the steamboat and the cistern that can be mapped in the top 120 meters. This indicates that the two systems are likely connected by a network of cracks rather than “open pipes”.

From recent multidisciplinary work at Steamboat and other geysers, it has become clear that deeper storage of energy in the plumbing system can lead to more powerful (and larger) eruptions. This could explain the origin of the impressive Steamboat eruptions – it’s the tallest geyser in the world, after all. However, there is still little understanding of the role of the large reservoir associated with the cistern and whether this structure affects the Steamboat Geyser eruptions. Understanding these relationships requires a more detailed study of the fluid and heat transfer within the fractured subsurface medium.

With campaign-style seismic operations, scientists can only record signals within a short window of time. These results provide a basis for a better understanding of the system, but the question remains: What are seismic sources like when Steamboat is in a less active phase? And how could continuous monitoring be used to better understand the steamboat cistern system? Hopefully future experiments will provide even more insight into Steamboat’s spectacular eruptions and its fascinating relationship with Cistern Spring.