Steamboat Geyser, in Yellowstone National Park's Norris Geyser Basin, is the world's tallest active geyser. Steamboat Geyser has two vents, northern and southern, approximately 20 feet (6.1 m) apart. The north vent is responsible for the tallest water columns; the south vent's water columns are shorter.[3]
Prior to 1904, Waimangu Geyser, in New Zealand, had some taller eruptions capable of reaching 1,600 feet (490 m), but in 1904, a landslide changed the local water table, and since then, Waimangu has not erupted.[4]Excelsior Geyser in Yellowstone's Midway Geyser Basin, and Semi-Centennial Geyser just north of Roaring Mountain on the Grand Loop Road were reported to be as tall as Steamboat, both with eruptions reaching 300 ft (91 m).[5] However, Excelsior has not erupted since 1985, and functions as a hot spring, and Semi-Centennial's one eruption of this height was reported in 1922 and it has been dormant since.
Steamboat's major eruptions generally last from 3 to 40 minutes (several durations surpassing an hour were observed during the 2018 active phase[6]), and are followed by powerful jets of steam. During these eruptions, water may be thrown more than 300 feet (91 m) into the air.[7] Steamboat does not erupt on a predictable schedule, with recorded intervals between major eruptions ranging from three days to fifty years. The geyser was dormant from 1911 to 1961. In 1964, twenty-nine eruptions were reported,[8] setting a record for the most eruptions within a calendar year. In 2018, the geyser began a prolonged period of frequent activity lasting through at least 2022, with more than 40 eruptions recorded annually in both 2019 and 2020.
Minor eruptions of 10 to 15 feet (3.0 to 4.6 m) are much more frequent.
After an eruption, the geyser often vents large amounts of steam for up to 48 hours.[9] Sometimes during this part of an eruption, water may return to Steamboat, causing it to jet water once again, though to lesser heights.[6] Cistern Spring, located nearby, will drain completely following a major eruption of the geyser; the spring refills within a few days.
Recent eruptions and active phase of 2018–2024
The most recent eruption of Steamboat Geyser occurred on October 7, 2024.[10] This was the 168th eruption since it re-activated in early 2018.[11]
In 2019 the 48th eruption occurred on December 26. That set a new record for the most eruptions within a calendar year. The calendar year 2020 also saw 48 eruptions, tying the record set in 2019.[12]
In 2018, Steamboat Geyser entered a much more active period with 165 major eruptions recorded between March 15, 2018, and May 7, 2023 [13][6][14][15] 32 eruptions occurred in 2018, 48 in 2019, 48 in 2020, 20 in 2021, 11 in 2022 and another 9 in 2023. This broke 1964's record of 29 eruptions within a calendar year.[16] The 2018 record was broken on August 27, 2019, with the 33rd major eruption of the year.[17]
^USGS' Steamboat counter lists this eruption as 3:23 AM, though in-basin report and seismic signal indicate 4:23 AM as start time.[19][20] This has since been corrected to 4:23 AM.