Graph showing all recorded eruptions since 1850, the time between eruptions ranges from 1 year to 28 years with an average of 14.7 years. The 22 year average being quoted is possible if the 1969 eruption is ignored. There were no recorded eruptions before 1953.
2019 Google earth image of the Piparo area with the Kugler 1959 legacy mud flow coverage superimposed. Potentially the whole village can be affected by a catastrophic eruption.
Activity has been monitored at Piparo since the 1997 eruption at least once a year. The main area of activity has remained in roughly the same place since the eruption , from 2003 to 2019 a number of small vents have also remained in the same location.
It is also important to note that the level of activity was not affected by the seasons (wet and dry) The rain allowed one to see minor gas seeps in water filled cracks, this gas was most likely escaping during the dry season but not noticed.
The 2011 -2012 “event”
The most recent activity was reported by villagers at the end of November 2011, a media frenzy erupted, with villagers reporting loud explosions, mud being ejected, being traumatised, not getting help from the government etc. On visiting Piparo, the reality turned out to be different, there was one area of mud and water from which gas escaped every few minutes. A video of this activity was posted on You Tube to refute villager’s claims. The activity was taking place at a formerly inactive cone , in May 2011 the cone was being washed away by rain, however large extensional cracks began appearing at the top. In late November – early December 2011 there was a crater about 5’ in diameter, the center was filled with viscous mud through which a large gas bubble escaped every few minutes. By the 2rd of January 2012 activity had been reduced to a few gas bubbles escaping through viscous mud, by June all activity has ceased.
At the second group of cones / activity in late November 2011 consisted of a single point of thin mud issuing from the edge of the cones, by the 2nd of January 2012 the top had collapsed leaving a crater about 4’ deep in which was very viscous mud through which bubbles of gas escaped, the edges of the cone continued to collapse so that there is a large crater on the cone where gas continues to bubble.
In November the only activity was mud and gas escaping, by the 4th December it was obvious that subsidence (Fig. 15-16) was taking place across the center of the mud volcano. Long WSW – NNE cracks had appeared, the ground between the cracks had subsided about 6”, some new vents appeared along these cracks. On the 3rd of January 2012 (Fig. 17 – 18) subsidence along WSW – NNE trending cracks had increased, and a large number of other cracks radiating NW- N away from the northern WSW-NNE trending crack. Subsidence on all these new cracks was down to the east. By January 15th 2012 a new SW-NE group of cracks appeared. Since then there has been no more subsidence.
Surface elevation changes were noticed between 2007 – 2012 at a number of vents. From 2008 – May 2011 there was a gradual increase in elevation, between May – November 2011 there was a rapid increase after the 27th November elevation decreased just as rapidly and has remained fairly constant up to June 2012. Heights increased once more in 2013, but with no additional mud vent activity. Cyclicity of mud vent activity, changes in elevation and appearance of fractures may be related to the sub-surface movement of mud . The apparent decrease of vent activity and appearance of fractures may be due to the withdrawal of mud or release of gas pressure ,resulting subsidence of the central area.