Yellowstone Volcano Observatory 2020 Annual Report

Circular 1482



The Yellowstone Volcano Observatory (YVO) monitors volcanic and hydrothermal activity associated with the Yellowstone magmatic system, conducts research into magmatic processes occurring beneath Yellowstone Caldera, and issues timely warnings and guidance related to potential future geologic hazards. This report summarizes the activities and findings of YVO during the year 2020, focusing on the Yellowstone volcanic system. Highlights of YVO research and related activities during 2020 include an active-source seismic experiment to image the top of Yellowstone’s magma reservoir; semipermanent Global Positioning System array deployment, including a new site near Mary Mountain; studies of hydrothermal activity in the southwest portion of Yellowstone National Park; numerous geological studies, including characterization of hydrothermal explosion craters, updating existing maps, and refining the ages of Yellowstone volcanic units; investigation of a dormant period at Old Faithful Geyser that may be related to regional drought 800–650 years ago, and development of a publicly available online map interface.

Steamboat Geyser, in Norris Geyser Basin, continued the pattern of frequent eruptions that began in 2018 with 48 water eruptions in 2020, matching the record for a calendar year that was set in 2019. Giantess Geyser, in the Upper Geyser Basin, erupted for the first time in 6 years in August 2020 and experienced a second eruption in September. Patterns of both seismicity and deformation in 2020 were similar to those in 2019. Deformation patterns during 2020 showed trends that were similar to previous years. Overall subsidence of the caldera floor, ongoing since late 2015 or early 2016, continued at rates of a few centimeters (1–2 inches) per year, and minor subsidence of Norris Geyser Basin that began in 2018 slowed during 2020 and stopped by the end of the year. Throughout 2020, the aviation color code for Yellowstone Caldera remained at “green” and the volcano alert level remained at “normal.”

Suggested Citation

Yellowstone Volcano Observatory, 2021, Yellowstone Volcano Observatory 2020 annual report: U.S. Geological Survey Circular 1482, 44 p.,

ISSN: 2330-5703 (online)

Study Area

Table of Contents

  • Introduction
  • YVO Activities
  • Seismology
  • Geodesy
  • Geochemistry
  • Geology
  • Yellowstone Lake Studies
  • Heat Flow Studies
  • Geysers and Hot Springs
  • Communications and Outreach
  • Summary
  • 2020 Publications
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Yellowstone Volcano Observatory 2020 annual report
Series title Circular
Series number 1482
DOI 10.3133/cir1482
Year Published 2021
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Volcano Science Center
Description v, 44 p.
Country United States
State Idaho, Montana, Wyoming
Other Geospatial Yellowstone Plateau
Google Analytic Metrics Metrics page
Additional publication details