| Note: | 04/11/1973 Echinus: one eruption was observed and timed. It was preceded by a pattern of activity which has not been seen before in at least the last three years.
12:12 (approx) moderate bubbling over Vent began
12:15 pool filled (dome shaped rock covered)
12:22 very vigorous bubbling as if eruption was going to start (1 min)
12:25 very vigorous bubbling , same as 1222, pool continued to have moderate bubbling in between
12:28 same “ “ “
12:31 moderate bubbling ended, pool quite (recycled) duration up to now 19 mins
12:32 moderate bubbling over vent resumed, water started to flow into west aextension of pool for first time.
12:34 very vigorous boiling, same as 1222
12:37 Eruption of Echinus began. Duration: 3m31sec estimated maximum height: 80 feet.
It now appears that Echinus has at least two types of recycles; one when water flows into the west extension of the pool, usually over flowing with vigorous bubbling over vent, followed by a quiet period over the vent and a drop in the water level of the pool by about 2 inches. The second type is described above in today’s observation a cycle of 1 minute of very vigorous bubbling every 3 minutes – sort of recycling within a recycle. |
