| Note: | 04/18/1973
Echinus – a big change was observed today: the water is now a very turbid gray (with a slight tinge of blue) In fact, when the pool is drained after an eruption, the water is almost opaque. In the runoff channels much fine-grained gray sand has been deposited.
The change has also had an effect on Echinus’s eruptive behavior. In the 5 eruptions observed this afternoon all of them went off without recycling, started before the pool was completely full, i.e. before the dome-shaped rock on the north side was covered, had a shorter interval, and played for longer durations.
An account of its activity is as follows:
1240 eruption began. There was virtually no boiling over vent (less than 10 seconds) before play began at a level approximately 2 inches below the dome-shaped rock.
Estimated maximum height was near 70 feet.
Duration: 3m45s
Next eruption: rapid boiling began when the pool water level was a full 4 inches below the top of the dome-shaped rock at 1:20 pm.
Pool became calm at 1:24 pm but still filling.
Bubbling started approximately 10 seconds before beginning of the eruption when still 2 inches of the dome-rock were exposed.
Eruption began at 1328
Measured maximum height 52 feet
Duration: 3m46s
Interval from previous eruption: 48 min
Next eruption: as before, bubbling started when pool level was still 4 inches below dome rock at 2:09 pm
Pool quiet at 2:11, gentle bubbling at 2:12
Vigorous bubbling started 7 seconds before beginning of eruption when about 2 inches of the dome rock were exposed.
Eruption began at 2:17
Measured maximum height: 85 feet
Duration: 3m45s
Interval: 49 minutes
Next eruption: much the same as before in the 2:17 eruption.
Bubbling started 7 seconds before time of play when approximately 1 ½ inches below top of dome rock.
Activity was witnessed by 18 visitors!
Eruption: 3:06 pm
Measured maximum height: 93 feet
Duration: 3m50s
Interval 49 minutes
Next eruption: same as before except pool level rose to 1 inch below top of dome rock before playing and that bubbling preceded eruption by 13 seconds.
Eruption: 3:55 pm
Measured maximum height 76 feet
Duration 3m41s
Interval 49 minutes |
