| Note: | 04/08/1973
Echinus: two consecutive intervals and durations were obtained. As has been suspected the eruptive pattern has changed significantly over what it had been for at least the past three seasons. Its behavior this evening was as follows.
5:20 pm eruption began
6:17 pool refilled
5:23 bubbling over vent (in middle of south side) began
6:26 pm second observed eruption began, played for 3 minutes, 5 seconds. Estimated maximum height was 75 feet which occurred approximately 15 seconds before the end of the eruption.
6:30 pm pool required 4 minutes to drain
(observations temporarily suspended – between 6:34 & 7:25 pm)
7:25 pm bubbling over vent begins, lasting 3 min, pool recycled
7:36 pm Bubbling begins again, lasting 4 min, pool recycled
7:43 pm Bubbling began again, lasting 2 min, until eruption
7:45 pm Third eruption began, duration: 3 minutes even.
(By this time it was too dark to estimate the maximum height or to time the draining of the pool.)
Thus the two intervals were 66 and 79 minutes respectively; the two durations were 3 min6 sec and 3min0sec, respectively.
Just for comparison (although only 2 eruptions may certainly not be representative of the current normal values), the average interval for the 1972 summer season was 46.0 minutes and the average duration was 3minutes 28 seconds, which was little different form the 1971 average of 47.5 min. |
