A. For years Echinus erupted every 35 to 75 minutes, depending on how long the previous eruption lasted. Late in 1998 this geyser began to alter its interval again and now its eruptions may be hours, days, or months apart. Echinus is affected by seismic activity and basin-wide disturbances. Checking in with a ranger at the Norris Museum is always a good idea.

Q. What is a basin-wide disturbance?

A. Periodically, Norris Geyser Basin undergoes a large-scale change. This change is manifested in water level fluctuations, temperature changes, pH changes, color changes, and eruptive pattern changes in features throughout the basin. Some features become murky, others, like Echinus Geyser, are less predictable. Geologists and water chemists have studied these disturbances, and there are several theories about why they occur. Some say the disturbances are a massive fluctuation in the underground reservoirs that provide water to the basin. We do know that Norris has several water systems that supply water to various parts of the area, some call them stacked water systems. Some theorize that because the disturbance usually occurs in the fall there is less surface water mixing with water from deep underground. The water from deep underground holds more silica and clogs the cracks and crevices that supply water, thereby creating a "disturbance" as pressure builds. Who really knows at this point? Exciting things happen during disturbances though. A small geyser, Porkchop, became a continuous jet of steam and water in 1985; during the fall of 1989, at the onset of disturbance, Porkchop clogged with silica and blew up. Rocks from the apron around the geyser flew 200 feet! When you hear the disturbance is on at Norris, come see the changes! Disturbances usually last for a few weeks, and then the basin returns to a more "normal" state.

Q. When can we expect to see Steamboat Geyser erupt?

A. Don't hold your breath. Steamboat Geyser erupts without much warning and with no pattern that we've figured out. The last eruption was in May 2005. It erupted three times in 2003, twice in 2002, and once in 2000. Prior to that it had not erupted since October 1991. When active, it can erupt as frequently as every four days, but it has been known to skip 50 years. There are no reliable indicators for Steamboat.

Q. Why is this place so colorful?

A. The colors at Norris, like in other thermal areas, are due to an interesting combination of minerals and lifeforms. Norris tends to have more milky blue features than other areas due to silica in suspension in the water (this is because the water is so hot and dissolves lots of silica). You'll also see a lot of red-orange. Some of the orange is due to cyanobacteria, but a great deal of the red-orange at Norris is due to iron oxides and arsenic compounds. Never drink the water at Norris! There are springs at Norris that are emerald green in color; this is due to the blue of refracted light in combination with the yellow of sulfur lining the pool.

Q. What exactly is a geyser basin?

A. A geyser basin is an area that contains thermal features, especially geysers. We refer to them as basins because they are nearly always lower than the surrounding terrain due to erosion, faults, and the underlying hot water.

Q. Why can't I smoke here?

A. Geyser basins are fragile places. Litter of all types is a problem, but cigarette butts can become especially numerous if smoking is allowed in an area. Also, most thermal areas have sulfur deposits lying on the surface. When sulfur catches fire, dangerous, sometimes lethal, fumes are given off. This is a chance we just aren't willing to take.

Q. Why can't my dog walk the geyser basin trail with me?

A. Dogs don't seem to recognize the difference between hot and cold water. Dogs have lost their lives diving into hot springs. Dogs also disturb wildlife and frighten other visitors.

Q. Is it really dangerous to walk off the boardwalk?

A. Yes!!!!! Places like Norris are constantly changing and have hollow areas that may have only a thin layer of rock over them. Boiling water surges just under most of the basins. Most burns received in thermal areas are second and third degree. People have died from falling into thermal features.

Q. Do animals ever fall into the hot springs?

A. Yes. Although animals usually know where to walk instinctively, they occasionally break through the thin crust. They also may be frightened by passers-by and run into a hot pool. Always keep your distance from animals, but especially in the thermal areas.