Is Kick ’em Jenny growing towards the surface of the sea?
Kick-‘em-Jenny does NOT appear to be growing towards the surface of the sea, although until recently, this was thought to be the case. This interpretation was based on the fact that a depth measurement of 236 m obtained in 1962 was much greater than all subsequent depth measurements, which range from 190 to 160 m. However, a recent re-evaluation of the 1962 survey results by the staff of the Seismic Research Unit clearly shows that the boat missed the summit altogether during this early survey, and the value of 236 m in fact represents the depth to a point on the western flank of the volcano. The next survey, in 1966, revealed a depth to summit of 190 m and the most recent survey (March 2003) a depth to summit of 180 m. These depths are essentially the same, within error. We can therefore say that Kick-’em-Jenny has NOT grown any closer to the surface between 1962 and 2003. The summit (western crater rim) has consistently remained at about 180-190m below sea level, except during a period in the late 1970s to early 1980s when a dome grew in the crater, temporarily decreasing the depth to summit to 160 m, before the dome collapsed in the 1990 eruption.
It is of course possible that future eruptions at the volcano may result in a shallowing of the summit, and gradual (or even rapid) growth towards the sea surface.