On the morning of July 29, 1968, after 10 hours of intense
seismic activity, Arenal erupted explosively and continued
to erupt over a period of three days, killing 78 people and
devastating 12 square kilometres. The activity started with
a lethal lateral blast that levelled the densely forested
western flank and destroyed the village of Pueblo Nuevo, 6
km west of the summit. The initial blast was followed by
Plinian eruption columns, pyroclastic flows, and
ballistically ejected blocks and bombs. Three new craters
(A, B, C) were formed during this time, with an
approximately east-west orientation on the western flank
of the
volcano. The largest, crater C (1100 m), was the source of
all the major explosions. These events were followed by
three days of relative calm consisting of minor ash and
fumarolic activity. A fumarolic phase began August 10 and
continued to September 14. Activity was noted at all of the
craters, with the most intense activity at crater C.
On May 5, 1998 around 1:09 p.m, several pyroclastic flows
descended from crater C down the northwest flank. This
activity kept on up to 7:00 p.m. A total of 23 flows
were produced with distances averaging 1.5 km.
Picture: Periódico Al Día.
