World’s tallest geyser erupts in Yellowstone

Steamboat Geyser, the tallest active geyser in the world, delighted visitors to Yellowstone National Park on Wednesday, spewing steam high into the air in a rare and powerful eruption that lasted several minutes and resulted in continuous steam and rumbling that persisted until Thursday morning.

Full eruptions of Steamboat are rare and unpredictable, and are prized by geyser gazers who hope to witness a rare column of super-heated water that can reach more than 300 feet.

Steamboat eruptions can last only a few minutes or as long as 40 minutes, with this week’s outburst lasting a reported 20 minutes or more, according to electronic monitoring records from the U.S. Geological survey. Once the major water eruption subsides, Steamboat typically enters a phase of smaller, ongoing steam ejections that can last for 1-2 days. Minor eruptions reaching 10-40 feet are more common than major 300-feet outbursts.

Intervals between major eruptions can span years or even decades, although Steamboat appears to have become more active over the last few years. The last major eruption of Steamboat, located in the Norris Geyser Basin, was in July 2013.

Janet White, who maintains the Geyser Watch website, said that “scattered reports on Steamboat throughout the summer have pointed to a possible eruption at some point,” and that geyser gazers will be anxiously watching to see if this week’s eruption signals any potential change in behavior for the famous thermal feature.

Andy Millard, a financial planner from North Carolina, happened to be nearby with a videocamera Thursday morning after Steamboat’s eruption the night before, and captured the geyser as it still spewed steam and rumbled mightily.

In posting the video to YouTube, Millard noted that his guide for a scheduled wildlife tour convinced the group to make a quick detour to Steamboat—a happy coincidence that resulted in capturing part of the steam phase on video.