Aurum is a beautiful cone-type geyser. The height varies from 15-25 feet, the duration is about 90 seconds and the interval can be from less than 3 hours to many hours. During some periods, Aurum is very regular and predictable. At other times its intervals are erratic and often long. One theory is that Aurum is affected by the surface water in the meadow behind the geyser. Observations seem to indicate that when the meadow is wet and marshy, Aurum's intervals are fairly regular and usually short, about 2-4 hours. When the meadow is dry, the intervals are often erratic and anywhere from 4 hours to more than 12 hours. The meadow is usually wet in the Spring, early Summer and late Fall when there is plentiful rain and snow. In the late Summer and early Fall, the meadow is usually dry unless there has been a recent heavy rainstorm.
On a few rare occasions, Aurum has been observed to have a series of two eruptions. In these cases, the second eruption followed the first by 5-10 minutes and was of slightly shorter duration.
Aurum is a fun geyser to watch. It is close enough to the boardwalk that during a strong eruption, its angled plume can travel over and past the boardwalk. The water, after its flight through the air to the boardwalk, is warm but not scalding, so don't be too alarmed.
|After an eruption, Aurum is quiet. Activity increases as the next eruption approaches. First splashing becomes visible in the vent. The splashing varies in intensity but as time progresses the overall splashing and intensity increases. As the eruption gets close, the splashing and boiling becomes almost continuous and will often have short surges to one to two feet high. A half hour or more before the eruption, two small side vents to the right of the main vent also start splashing. Then, as the geyser gets even closer to erupting, a crack in the sinter between the two side vents and the boardwalk starts to bubble and surge a little. At this point, with the main vent boiling almost constantly and surging periodically to a foot or two, with the two side vents splashing and with the small crack gurgling, one of two things can happen. If the geyser is being regular, there will probably be an eruption within the next 30 minutes. If the geyser is being irregular, this type of activity may continue for 4 or more hours. To judge what is going to happen, it is best to know what the recent intervals have been and if it has been regular. If you don't know this or even if you do, you should look at the meadow behind the geyser. If it is wet, with standing water, then the interval will likely be short and the geyser probably will erupt relatively soon. If it is dry, then be prepared for a long wait.