Descriptions of Springs, Part 2

#23n—Geyser

This is a small opening about 20cm by 10cm, and only about 10cm deep. Eruptions are about 30cm to 1 meter high.

Its first observed activity was in November 1983 with a height of 1m and intervals around 3-4 minutes. It was subsequently dormant, filled by algae and debris washed in by the runoff from #106.

Even though runoff from #106 ceased around February 1986, no activity was observed until 08 September 1986, when activity consisted of eruptions about 1/2 meter high every minute and lasting about 20 seconds.

In the autumn of 1986, this spring was one of those which reactivated following the testing of the well 28-32. At first it was erupting regularly, while later, in November, it showed a relationship to nearby #113. This latter spring would cease erupting when #23n would erupt, then restart after #23n ended.

The eruption heights were unchanged, but the durations were now about 1m30s, and the interval was about 5 minutes. When #23n ceased erupting, #113 would then erupt, only ceasing when the next eruption of #23n began. On one occasion, there was a short (15sec) minor eruption about 1 minute before the major eruption of #23n.

Two weeks later the activity of #23n had again changed. This time it was having a series of major eruptions separated by from zero to two minor eruptions. The major eruptions lasted about 1m20s. A minor eruption only lasted about 15sec to 20sec. The interval from a major eruption to the next eruption ranged from 4m30s to 5m. If this eruption was a minor, then the interval was about 1m30s.

By the end of November it reverted to the activity observed in September, with durations around 20 seconds and intervals around 50 seconds.

By 10 January 1987 it had ceased erupting, but on 02 May 1987 it was induced to erupt several times. These eruptions lasted 40sec to 1m34s. The shortest interval between these eruptions was 8 minutes.

#24—Geyser

This spring does not seem to have changed much since a photograph was taken of it around 1950 [White 1968], pg.20. It is a fissure at least 10m long, with the discharge taking place at the northern end. The built up ridges at the northern end, and the length of the spring suggests the name “Sluicebox Geyser.” The actual vent seems to be buried among the collapsed walls of the southern end of the fissure. In October 1986 three distinct areas of boiling were observed. The play among the three vents varied, and no pattern was noted among them. The heights ranged from 15cm to 50cm.

A month later it was found that this spring could be induced to have an eruption about 2m high. This occurred after a half hour of foamy play about 50cm high.

Until Well 28-32, this spring flowed continuously, and had a large, wide algae mat running down slope. When dry, this area turned out to be stained gray by the considerable quantities of minerals in the water.

#24e—Geyser

This geyser was reported to be active during the winter of 1985. It has not been seen by any GOSA observer, but has been reported to erupt as high as 5m [Otto 1985]. It is a crack about 3m long located just south of the main runoff coming from #24. The vent is stained gray, and widens at the southern end. There is a wide area around the vent clear of gravel, a good sign of recent activity.

During the Winter of 1986, water was observed about 15-30cm below the vent. An attempt was unsuccessfully made to induce it.

#24sw—Geyser

A irregular, narrow slit about 15cm to 30cm wide and 4.5m long. On 22 July 1983 this spring was observed to erupt about 60cm high. Later, on 30 November 1985 it was again observed erupting about 60cm high. There was no runoff, although some water did disappear down another opening immediately to the north. The average duration was 48 seconds, and the interval was 2m30s.

#26—Perpetual Spouter

Visits to the Lower Terrace, being farther south of the Main Terrace and across the highway, were uncommon. But whenever this area was visited, activity in this spring would be observed, the only activity in the Lower Terrace. This spouter would splash about 30cm out of its crack. This area was not checked, so the effects of Well 28-32 and the powerplant are not known.

#36ne

This opening is one of many along a crack near the crest of the Main Terrace. On 08 February 1986, the first of many new springs along this crack was observed. This activity slowly increased until the tests on Well 28-32 began, in preparation for the installation of the Steamboat Hills power plant.

By 22 March 1986, four new springs (#103, #104, #109, #110) were recorded along the crack, and two more to the west (#105, #111) were also noted. Until that day, #36ne was filled in with fragmented sinter and gravels. By that time, enough fragments had either been ejected or had been dropped deeper into the vent so that it was now a crack about 1m long, and splashing a few centimeters high.

#39—Geyser

This is a narrow crack, 6.7m long, located at the crest of the Main Terrace. It, along with #41s, and #102, were all first observed on 30 November 1985. Water is thrown at an acute angle, being ejected horizontally much farther than vertically. While active it was never observed to cease eruption. At first there was quite a bit of discharge, with the play about 1m high, and playing laterally to the east to about 2m. One impressive feature of this spring was the copious amount of material deposited by the runoff, which was a dull, greyish-black material, high in heavy metal content [Hudson 1986].

By 28 December 1985, the amount of discharge dropped dramatically, even though the height and vigor of the play did not seem to have decreased. There was some water thrown as much as 4m from the vent. On 08 February 1986, the activity was reduced, with only occasional droplets to 1.5m, and almost no discharge. This was also the case when observed on 23 February 1986.

#40—Geyser

This geyser has a small, narrow irregularly shaped vent surrounded by a broad area of gray sinter deposited by activity. Most of the overflow from this spring flows into two different cracks, one about 2m to the west, the other farther away and to the south.

Eruptions occurred as part of a series. After numerous frequent eruptions, the vent would drain, and there would be a period of quiet. In 1984 this period lasted about 6 to 8 minutes, while in 1986 this was only about 1 to 2 minutes.

The first observed eruptions took place during a general cleanup of the springs in 1984. It was noted that several large rocks, as much as 30cm across and estimated to weigh about 30kg, were wedged deep in the vent. With considerable effort these were removed. “It was with some consternation that the eruptions following the cleanup were not as high as those preceding it. Those present mused that the rocks should be returned to their former resting place.”[Strasser and Strasser 1989]

Around noon at the time of the summer solstice it was once noticed that a reflection of water could be seen a number of meters down in the vent.

#41

Until 23 February 1986, this spring was just a depression in the terrace just north of the trio of #41s, #39 and #102. On that day it was observed that the bottom had enlarged, and water was bubbling through the gravel in several places.