Environmental Engineering Reference
In-Depth Information
Figure 3. soil profile showing how the Fuente santa
lies under 70 meters of debris, cinder and lava flows, and
the coast line retracted 400 meters offshore.
Figure 2. an image can be observed as a perspective
including, in addition to the coastal cliff and the tidal
ponds, the plain known as cuesta de cansado.
of year 1677 the san antonio volcano erupted, the
same one leading the view of cuesta de cansado.
The eruption lasted three months, until the end
of January of the following year, but the worst
came in only one week after the start. in such a
short time the 23 mouths that opened spewed lava
flows that buried towns, houses, the hermitage,
tilled fields and the worst that could have hap-
pened to la Palma: the burial of Fuente santa
spring under a 70-meter thick layer of debris, cin-
ders and lava flows.
The process of vanishing of Fuente santa is
narrated by nicolás de sotomayor, special envoy
of the cabildo (Town council) to Fuencaliente to
write a report of the daily happenings during the
eruption. Thanks to this detailed account we know
that on november 23 one lava flow erupted at the
foot of the volcano, one of the 23 mouths of hell
that opened, carrying out a flow of stones and cin-
ders resembling a drifting boulder. They reached
to the edge of the cliff, at the foot of which the
tidal ponds stood and a further thrust from the
averno made that all stone laden flow fall through
the notches wearing away part of the cliff. Within
a moment such boulder beach became flooded and
both ponds disappeared under tons of debris. after
such a ramp was formed, the lava flow, pushed by
the thrust of the magmatic chamber, ran along the
slope until the sea shore was reached thus enlarg-
ing the island under the continuous lava flow.
When the nightmare came to an end the land-
scape looked devastated: where the fields and
houses of cuesta de cansado stood, only a dan-
tesque panorama was left constituted by the vol-
canic malpais and no vestige remained that only
three months before an unlimited richness and
prosperity existed at that place.
But the worst was not only the loss of goods
and lands; the unbearable was that the coast was
Figure 4. a perspective depicting the devastated land-
scape around cuesta cansado, where the town, hermit
and agricultural fields disappeared.
not the same any more: the cliff walls had vanished
among rock falls and were buried by the debris and
lava flows. at the site formerly occupied by the
Fuente santa spring only a pile of rubble remained,
attached to the former cliff and since the sea shore
was now covered.
The coast line retracted 400 m offshore. The
spring became buried under an avalanche of
rock at a depth of 70 m of burden material. (see
The first attempt made to dig up Fuente santa
was made only ten years afterwards (1687) when
remembrances were still fresh and the inhabitants
of Fuencaliente could still recognize the original
location, even after being buried, of the miraculous
thermal spring. This try was followed by up to 16
attempts that already had to struggle against two
serious problems. The first one was where to exca-
vate, because with the exception of the first attempt,
in the others nobody knew where the spring was
buried; the second problem referred to the lack of
stability of the material to be excavated.
