EMERALD SPRING—The colors in and around thermal features are often
created by several kinds of algae that grow in hot water. However, the
deep green color of this spring is a result of a combination of the
yellow color from the sulphur lining the edge of the pool with the blue
that is refracted (“scattered”) from the clear water in the pool. The
bowl of this feature is about 27 feet (8 m.) deep and the temperature
normally varies between 194 and 200 degrees F. (90-93° C.)
STEAMBOAT GEYSER—The world’s largest geyser, Steamboat has eruptions of
more than 300 feet (91 meters). It was largely dormant for nine years,
then startled observers in March 1978 with a full-scale eruption. The
water phase lasted approximately 20 minutes, followed by bellowing steam
for over 40 hours. This spectacular display inundated the immediate
area. At this writing, March 30, 1978, it is not known if Steamboat’s
eruptions will follow any pattern. Between 1961 and March 1969, it had a
total of 103 major eruptions, none of which could be predicted. You can
still see the effects of downpouring water on the landscape which killed
trees and scoured away soil. The nine-year respite allowed new lodgepole
pines to gain a foothold. We hope you are fortunate enough to witness
Steamboat Geyser and share in the excitement. Remember—protect camera
and eye glass lenses from the spray as it can scratch glass after
drying.
CISTERN SPRING—In 1966 this feature changed from a grayish-black color
to its present brilliant blue. Concurrent with this the overflow
increased killing many trees near the spring. Since then a silica
terrace has rapidly built up. When Steamboat had a major eruption the
water level in Cistern dropped 4-8 feet, (1.2-2.4 m.) with a
corresponding drop in water temperature of around 60 degrees F. This
seems to indicate some connection between the two features. Whether or
not the increased water output of Cistern has resulted in the decline of
Steamboat is still unknown.
ECHINUS GEYSER (ē-kī′-nŭs)—although not as well known as some other
geysers, erupts in a display that surpasses many of them. The name comes
from the sinter spine-covered rocks surrounding the pool which bear a
fanciful resemblance to spiny sea urchins. _Echinus_ was the Greek name
for these tide-pool dwellers. Stop and watch the water fill the basin
and begin to boil. Soon it will be propelled skyward in great explosive
bursts of steam and water, some reaching heights of over 75 feet (23
m.). Usually the eruptions last three to six minutes but in 1977 Echinus
was erupting for up to twelve minutes. After erupting the pool drains
and begins to refill. Intervals between eruptions may be as short as 45
minutes or better than 75 minutes. Listen for the peculiar gurgling
sound produced as the vent drains after each eruption.
VIXEN GEYSER—Although its usual eruptions are small compared to others
(5-15 feet every few minutes), the geyser is unique in that water comes
from a circular tub-like vent. During normal activity little water is
ejected. Occasionally Vixen may have major eruptions of considerable
water, lasting 5 to 50 minutes and playing up to 30 feet. Listen for the
peculiar gurgling sound produced as the vent drains after each eruption.