Sunday, 28 June 2015

Day 14 - San Antonio volcano

Today is Paulo's last day with us before heading home to Cape Verde.

Though today is a day of sampling, business as usual, there is a feature we sampled around that is worth discussing a little, so here I go!

Along with the most southerly volcanic centre of Teneguia, responsible for the 1971 eruption, there is a much larger volcanic cone immediately above Teneguia that was responsible for the 1677 eruption. Together these two volcanic centres are responsible for extending the land mass of the island of La Palma in a southerly direction.

San Antonio crater taken from the western crater rim

The eruption of San Antonio was a Strombolian style eruption that resulted in minimal destruction to the area. However, the lava flows were responsible for burying Fuente Santa, the hot spring that is the namesake of the municipality of Fuencaliente. 

Fuente Santa, or Holy Fountain, was a hot spring whose waters were believed to hold healing properties by European travellers and the ancient inhabitants of the island alike. The waters were even shipped to South America, bringing some wealth to the area. Its powers were so amazing to the people that it was also referred to as Fuente Caliente - Holy Source. 

In writings by Nicholas Sotomayor "On November 13, 1677, a quarter of an hour before sunrise, the Earth shook and the underworld opened at the foot of the Mount of Los Corrales. Several lava flows were diverted away from the hot springs, but on November 23, a large flow moved towards the spring and no more could be done to stop the inevitable. This lava flow was coupled with the collapse of part of the cliff where the source of the hot spring was located. Despair among the people of the area raged as the spring was buried and the land was extended to the sea by 400 meters. 

Fuente Santa (image from

Recently, the Ministry of Public Works of the canary Islands Government in collaboration with the City of Fuencaliente has discovered the location of the springs and established access. Analysis of the waters reveals high salt an CO2, as well as water temperatures of 60 degrees Celsius. It is hoped that in the near future, these waters will once again be used in a spa that will bring additional wealth back to the region. 

Down near the coast, among the lava flows of this eruption, where roads now cut the flows, it is possible to observed some good examples of lava flows in cross section that demonstrate the rubbly top and base and a solid core with vesicles elongated with the flow direction. 

Cross section through a lava flow

The rubbly at the top and base of the lava flow is due to these surface coming in to contact with the cooler underlying deposit and the atmosphere. The outer edges of the flow begin to cool but the core of the flow continues to move. The friction generated between the still flowing lava and the cooled and partially crystalized outer edges causes the outer edges to break up in to small blocks, resulting in the rubble. 

Every day is an adventure!

Buenos noches de La Palma!

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