| Note: | 09/06/1971
A new thermal feature located about 48 feet north west of the west edge of Corporal Geyser’s pool apparently has increased in activity with much erosion during the night and its first known recent play occurring between 9:40 & 10:10 AM. This is probably an enlargement or extension of the “small {new} vent” which was reported to have started to play in July in the Norris Thermal record.
The thermal feature is aligned on a NW-SE direction with Corporal & Dog’s Leg, apparently along a joint, with its greatest dimension in this direction. It is irregular in shape with its present measurements as follows: Length: 11’8” (starting under a “live” small green lodgepole pine on the N.W. to about 1 ½ feet beyond an old dead stump on the SE); width: varying from 34 to 72 inches, and maximum depth: 11 inches.
Play was observed at 4:35, 5:24, 6:09, 6:58 (average interval ~~ 48 minutes). The play was preceded by increases in the amount of steam coming out of the ground, then a rapid filling and overflowing – starting first at the SE end, then spreading NW from other low points {filling phase lasting 40-60 seconds}. This was immediately followed by a vigorous boiling action throwing water, sand & geyserite chips to a height of 1 foot. “The eruption”, again starting & ending first at the SE end and starting & ending last at the NW end {duration: 2 minutes}. During the last 30-40 seconds of the play there is rapid draining of the water back into the ground finished off near the NW end by a final bubbling sound down below the surface. It is quite a sensation to set at the edge of the feature and feel the ground below you shaking vigorously! The bottom of the feature is made of small loose geyserite thin plates and porous tabular bodies of small geyserite fragments. R.A.H. |
