| Comments: | From Yellowstone Nature Notes, Vol. XV, No. 5–6 (https://irma.nps.gov/DataStore/DownloadFile/470330): "I first noted the activity on May 30, 1938, at 7:30 a.m. At this hour I saw several jets which seemed to rocket easily 200 feet. A number of similarly high eruptions were noted throughout the day. After making several inquiries and hearing numerous comments, I decided the eruption must have begun about 3:30 and not later than
4:00 a.m. During the course of the day the Giantess erupted periodically with intervals varying between twenty and thirty minutes. The average duration of each eruption, which was characterized by rocketing jets of water, was about five minutes. Activity was just as strong at 8:00 p.m. as during the morning hours. At seven-thirty the following morning, there was still a churning of water in the bottom of the crater. At no time during the day was
any water observed to be thrown above the rim. By 1:00 p.m. all boiling seemed to have ceased. By 6:00 p.m. water could be seen standing at a level near the bottom of the crater. At 7:30 a.m., June 1, the bowl was about two-thirds full and the periodical ebulition that characterizes the quiescent
periods of the Giantess was noted. The bowl
continued to fill at the rate of about eight inches an hour, beginning to overflow some time during the night of June 1. The Vault and Teakettle filled simultaneously. At the time of the first observation of the Giantess, May 30, the water had receded two feet below the rim of the Butterfly and was boiling vigorously. This boiling continued without abatement for a period of not less than 48 hours. On the morning of June 2, the bowl was overflowing, the water being several degrees below normal in temperature. The whitewashed appearance of the Giantess cone following the activity was only in a small measure the result of the algae having been destroyed by the boiling water. During the initial activity a large quantity of
finely suspended or held silica was ejected...In numerous collecting basins near the cone, this highly dissipated mineral had collected, giving the appearance of marl or a foraminiferal ooze." |