Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Jefferson Hungerford, Park Geologist, and Kiernan Folz-Donahue, Physical Science Technician, both with Yellowstone National Park.

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Geologists, geophysicists, and geochemists generate mountains of data when studying geologic processes. A single geologic event, like a landslide or a volcanic eruption, can yield terabytes of information! It’s an amazing volume that can be multiplied by the number of scientists that are working on a given project.

Almost all these data are spatially constrained.  That means they are associated with specific locations on the Earth’s surface, and thus can be represented as particular points on a map. Geology is the study of the Earth, and maps provide a simple form of data visualization. What did explorers do when they reached what were to them unknown lands? They made maps. What did the first Euro-American explorers do when they reached Yellowstone? Yep, more maps—like the map of Yellowstone Lake that was created during the first scientific exploration to what is now Yellowstone National Park in 1871. Those early cartographers would certainly be jealous of the technologies that are now available to make maps.

The advent and widespread adoption of Geographic Information Systems (GIS), especially since the 1990s, revolutionized the world of cartography. GIS can tie locations on a map to data about a place. For instance, earthquake epicenters can be plotted on a map with data about each earthquake’s depth and magnitude. Over time, these data can reveal changes occurring deep underground. GIS capabilities have grown exponentially over the last three decades, from simply placing information on maps, to now performing complex analyses of geospatial data and generating user-friendly, interactive maps hosted on websites, like the Geologic Map of Yellowstone hosted by the Wyoming State Geological Survey. Using ever-increasing GIS capabilities, it is possible to walk through three-dimensional projections of subsurface faults and folds in rock layers, once represented as lines on a flat maps but now viewable in “true form” through a pair of virtual lenses. With a technique called photogrammetry, Yellowstone’s geyser cones can be viewed as high-resolution 3D GIS representations!

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GIS tools have been used in Yellowstone in the creation of an inventory of hydrothermal features. In Yellowstone National Park, there are thousands of geysers, mud pots, thermal springs, and other hydrothermal features. An inventory of these features was started in 2018 to better understand their distribution and characteristics, and how they change over time. Nine hundred and sixteen separate features were located and inventoried in Norris Geyser Basin alone. Without GIS, stacks of paper datasheets would have to be individually cross-referenced to crudely-drawn hand maps, with sheets carefully cataloged to make sure none were misfiled or lost—a monumental task. Today, each feature is located precisely on a digital map by GPS, and records are made accessible for each sampling location at the press of a button. No more hunting down data! It is just as simple to revisit locations and add observations for subsequent years, building a picture of changes over time.

The result is an ability to analyze large datasets quickly and easily. For example, analysis of the Norris data showed that between around 2000 and 2018, hydrothermal water temperatures had increased in Norris’ Back Basin, Hundred Springs Plain, and, slightly, in Porcelain Basin. The increase in the Back Basin was especially dramatic, with vent waters being on average 15 °F (8 °C) warmer in 2018 compared to about 20 years before, while water temperatures fell 4 °F (2 °C) in the region of Norris known as The Gap. This time period spans the 2003 thermal event at Norris, as well as the reawakening of Steamboat Geyser in 2018, although any connections between these observations is unclear.

Yellowstone National Park scientists also use GIS to understand landform change in the park. Park scientists work with federal highway crews and other partners to analyze the suitability of certain areas for road projects and other infrastructure. Sometimes—heck, nearly always in national parks!—it can be hard to find land that is suitable for roads and visitor facilities. Park roads, for example, should avoid impacting landscape viewsheds and must not disturb unique geological formations or archeological sites. They must also be in areas that are stable and accessible. With GIS-capable software and analysis tools, it is possible to more easily identify those areas where roads are less likely to be washed away, be covered by landslides, or, in the case of Yellowstone National Park, be subject to geothermal damage.

These are just two of the many ways Yellowstone National Park scientists use GIS tools to collect, curate (that is, store and preserve), analyze, visualize, and disseminate information to other scientists and to the public. There are countless other ways to use GIS to create new approaches to look at scientific problems and develop solutions, and the tool dominates Earth science, from understanding the distribution of geological features to developing quantitative maps of geological hazards. So, if you or someone you know wants to get into the geology business, be sure to brush up on GIS skills!