| Comments: | During the 10 minutes before the eruption Ledge had minor play with steam surges and light water discharge once a minute on the average and strong heavy steam and water surging from the main and middle vents every 3-4 minutes on the average. It was during one of these periods of minor play with heavy surging that the eruption began. Yet the eruption had a “slow” beginning; between 4 and 6 of the heavy surges of water was required to get the geyser going. The basin over the southeast vent quickly filled to within a foot & a half of the top from its characteristic fountain-type play. In this eruption the fountain bursts played for approximately 2½ minutes reaching an estimated maximum height of almost 40 feet. Play in the southeast vent rapidly died down and at 3½-4 minutes into the eruption had drained. Just as the last of the water was going out of sight in the southeast vent the whole geyser faltered and almost aborted its eruption. In the main vent for example the water jet which had been up to a roughly estimated 100 feet was replaced for about half a minute by heavy surging 10-40 with momentary pauses. Gradually the surging became more continuous & powerful and the eruption was resumed to its conclusion. Before the near abort it was of interest to note that while standing on the base of the small ridge between Jetsam Pool and the sinter platform of Ledge at a distance of 25 feet one sharp hard thump was felt from the ground under foot |