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The Norris Geyser Basin was named for Philetus W. Norris who served as Yellowstone’s second superintendent from 1877 until 1882. Although he did not discover it, his explorations and reports were largely responsible for calling attention to that area.
Norris is considered to be the hottest and most active geyser basin in Yellowstone. Here geysers and hot springs exhibit greater change in activity over a short span of time than elsewhere in the park. It is not unusual for a new hot spring to come into existence literally overnight. The new feature may last for just a few days or perhaps a month or so; upon occasion some have endured for many years.
Because of constant change in the thermal features, the ground here is unstable and hazardous in many locations. Therefore, you are required to stay on designated trails and boardwalks at all times. This not only protects you from possible serious burns but also helps preserve the features as well. Remember also not to throw any objects into thermal features. Debris of any kind in a hot spring or geyser could clog the vent and destroy the feature. Because many scalding hot pools and run-off channels are near trails and boardwalks, pets are not permitted on the trails.
The fact that thermal features change may come as a surprise, but remember that geysers, hot springs and other thermal phenomena are subject to natural stresses just like plant and animal communities. Of course the changes in thermal activity result from a different set of factors than those affecting plants and animals. Can you guess what they might be?
Shifts in the earth’s crust (earthquakes) result in movements along cracks and fissures in the ground. These tremors usually cause changes in the underground “plumbing systems” of thermal features, thus altering activity patterns. Look for signs of recent activity variations as you walk along the trails, or ask a naturalist if there have been some recent changes.
As you explore, look closely at the often intricate formations around the edges of a few hot pools, geysers and in some thermal runoff channels. You will notice a mineral called sinter or geyserite (a form of silicon dioxide, SiO₂) being deposited like tiny spines. These rather prickly formations result when geyserite is deposited from slightly acid water, a characteristic of most thermal water in the Norris area. This is in contrast to the bead-like structures that result when geyserite forms from slightly alkaline water found in thermal features in the Old Faithful area.
Notice too the variety of colors staining the basins. The refraction (breaking up) of light, mineral deposits and living organisms, algae and bacteria, all add their hues. The assortment of colors reflects variations in water temperature and chemistry.
As you enjoy your walk remember that Norris is a great natural preserve where nature is constantly at work designing and redesigning one of its most unusual displays. We are only visitors here and must not spoil it in any way. It also serves as a great natural research laboratory where scientists from all over the world learn more about geothermal energy. Help us preserve this unique area so that the next generation and those who follow can come and enjoy it in the same grandeur you did.
The Norris Geyser Basin is made up of two or more less separate areas called Porcelain Basin and Back Basin. Both basins are served by trails which begin at the Norris Museum and are shown on this map. The following briefly describes a few features in each.
VALENTINE GEYSER—Located at the base of a large pear-shaped alcove, Valentine is a typical cone type geyser that first erupted on Valentine’s Day, 1907. Its activity has varied considerably—being dormant some seasons, erratic during others, yet showing a high degree of regularity at times. During the past several seasons, it has erupted from a minimum of once every two days to a maximum of once a day. An eruption lasts 5-7 minutes and reaches a height of 20-50 feet (6-15 m.) above the seven foot cone. The eruption is followed by a steam phase lasting an hour.
LEDGE GEYSER—The largest geyser in the Porcelain Basin, changed dramatically after an earthquake that occurred June 30, 1975. In 1974 it had been erupting about twice a day, but after the quake Ledge was dormant for nearly two years. Then during the summer of 1977 it had but two eruptions. Check the prediction board at the museum to see if Ledge Geyser is active this year.
AFRICA GEYSER—named for the spring that preceded it which was roughly the shape of the continent. The spring became a geyser in February of 1971. At first it was intermittent but as time passed the periods between eruptions grew shorter until it became a constant geyser. In 1977 it was always powerful—sometimes emitting a mixture of steam and water; other times just steam.
THE WHIRLIGIGS AND CONSTANT GEYSERS—these three features seem to be interconnected. Constant Geyser, dormant for several years, reactivated in the early ’70’s and now erupts up to 30 feet (9 m.) once or twice an hour; often prior to an eruption of one of the Whirligigs. In recent years, Big and Little Whirligig have traded active periods. When one is more active, the other is less. Watch for the 15 foot (4 m.) angled plume from Little Whirligig’s orange vent or listen to the distinctive chugging produced during Big Whirligig’s splashing eruption. As with many geysers, the water level rises in these pools prior to an eruption.
EBONY AND BEAR DEN GEYSERS—are another set of related features. In the ’60’s Bear Den Geyser first appeared and as it increased in activity, Ebony Geyser became dormant. Today Bear Den Geyser erupts in bursts, arcing up to 40 feet (12 m.) from the den-like vent, four to six times daily. The death of Ebony Geyser may have been hastened by objects thrown into its vent by thoughtless visitors. This debris is cemented into place by the silica deposited from the water, choking off the vent. Minute Geyser in the Back Basin may have suffered a similar fate.
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.
TODAY’S GEYSER PREDICTIONS
(Obtain data from the museum prediction board or from a naturalist).
Text written by George A. Algard, Norris Summer Naturalist 3/74
4/78
NORRIS GEYSER BASIN
DANGEROUS THERMAL AREA
Boiling Water—Thin Crusts
Always Stay on Constructed Walkways