The 2020 Yellowstone Volcano Observatory annual report is now available!

Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Mike Poland, geophysicist with the U.S. Geological Survey and Scientist-in-Charge of the Yellowstone Volcano Observatory.

Sources/Usage: Public Domain. View Media Details

How many earthquakes were located in the Yellowstone region in 2020?  What geysers have been active recently?  What sort of volcanological research is being done in Yellowstone right now?  It can sometimes be hard to find such information compiled in a single, easy-to-navigate source.

But not anymore.

We’re pleased to announce publication of the 2020 Yellowstone Volcano Observatory annual report, which can be accessed at https://pubs.er.usgs.gov/publication/cir1482!

The report contains an abundance of information about what happened in and around Yellowstone in 2020.  For example, there were 1,722 earthquakes located in the Yellowstone region during the year, the largest being M3.1, and 52% of the quakes occurred as swarms, 26 of which were documented during the year.  This is well within the range of normal annual seismicity—typically 1,500–2,500 earthquakes occur every year in and around the park! 

In terms of ground deformation, the caldera continued to subside at a rate of 2-3 cm (about 1 in) per year, as has been the case since 2015.  At Norris Geyser Basin, no displacements occurred during the year. 

Steamboat Geyser—the tallest active geyser in the world—continued its spate of activity, which started in 2018, with 48 major eruptions in 2020.  This matches the record that was set in 2019 for eruptions in a calendar year.  Giantess Geyser, near Old Faithful, erupted for the first time in 6 years, and Echinus Geyser—Steamboat Geyser’s next-door neighbor—had four eruptions in December (the first eruptions since January 2019).

Sources/Usage: Public Domain. View Media Details

But not all Yellowstone geysers were more active during 2020.  Giant Geyser, which had been enjoying a period of more activity during 2017–2019, did not erupt at all in 2020.  And in the southwest part of Yellowstone National Park, a well-known hot spring across from a trail along the Ferris Fork of the Bechler River went dry.  The changing activity of Yellowstone thermal features, some turning “on” and others turning “off,” reflects their normal dynamic behavior and is a hallmark of Yellowstone.  The one constant of Yellowstone’s hydrothermal system is change!

Scientists from the 9 member institutions of the Yellowstone Volcano Observatory were also busy researching Yellowstone’s geologic history during 2020.  Although the COVID-19 pandemic curtailed some field work, geologists were able to complete field studies and also wrap up laboratory work on such projects as:

• Mapping of the Pocket Basin and Twin Buttes hydrothermal explosion craters in Lower Geyser Basin
• Determining the ages of rhyolite lava flows that erupted after the formation of Yellowstone Caldera
• Identifying past hydrothermal explosion deposits in the sediment at the bottom of Yellowstone Lake
• Recognizing that Old Faithful was inactive 800-650 years ago due to a major regional drought
• Exploring thermal features in the remote southwest corner of Yellowstone National Park

The 2020 annual report is part of a series of USGS Circulars that began several years ago and that also includes entries that describe Yellowstone activity and research in 2017, 2018, and 2019.  We hope that you find the reports to be informative and enjoyable!

Summer is almost here, and field work is starting to ramp up.  We look forward to detailing all of YVO’s accomplishments for the coming season in the 2021 report, so stay tuned!