Anemone Geyser

Anemone Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Anemone is actually two closely related geysers. The larger of the two is known as Big or North Anemone while the smaller is known as Little or South Anemone. The two geysers were named after the anemone flower by the Hague Party in 1904. Both vents have a pale yellow color and shape similar to the flower.

Geology
Big Anemone has eruptions lasting 25 to 45 seconds every 6 to 10 minutes reaching a height of 6 to 8 ft. Water can be heard rising in the crater prior to eruption. After an eruption, the water quickly and noisily retreats into the crater.

Little Anemone has less vigorous but longer-lasting eruptions than Big Anemone. Interval between eruptions can vary from 6 to 35 minutes, and eruptions can last from less than a minute to more than 30 minutes. The fountain rarely reaches more than 4 ft in height, and on occasion the crater will fill with water then drain without erupting.

On occasion, Little Anemone has near non-stop activity. This causes Big Anemone to have very long intervals and weak eruptions. The Anemone geysers are also part of the weekly Geyser Hill wave, it increases and decreases their interval and duration over the course of a week or multiples of one week.