Thursday, 25 June 2015

Day 5 - The Learning Begins

An 8.30 am start and we are off!

It becomes immediately clear how geologically spectacular the island is. Lava flows over lava flows, lava channels some deeply incised, a'a' flows, pahoehoe flows, cooling fractures, lava tubes, cones, craters, the list is pretty long I must say. And I love it!!!!!!

It certainly is 'La Isla Bonita'.

So today I started on the soil gas sampling under the watchful eye of Samara and Hannah started on the CO2 efflux and surface temperatures under the watchful eye of Paulo.

Me getting stuck in to sampling for Helium.

The equipment used for soil gas sampling is surprisingly simple. Syringes, tubes, valves, needles, all medical. Glass tubes with one way rubber inserts so the gas will go in, but not come out. and a metal rod (a proof). The proof is hammered in to the ground to a depth of 40cm then a needle attached to a tube, valves and a syringe, is inserted in to the top of the proof. Gas is drawn out, then evacuated by adjusting the valves. The gas is drawn from the soils a further 2 times and each time emptied in to a glass tube; at 10% of the sites a third sample is collected. The amount of samples collected at each site can be adjusted based on the location you want to survey and what it is you want to analyse. Today 35 sites were sampled, totalling just under 80 little glass tubes for the day.

Some of today's sample sites were close to the coast. Here we could see the saltpans, the Fuencaliente lighthouse or 'Faro' and Volcan de Teneguia, the location for the 1971 eruption, the most recent on La Palma.

Faro de Fuencaliente in the foreground with Volcan de Teneguia (the source of the 1971 eruption) behind

There are few contrasts as striking as white salt on black basalt, interspersed with the reddish colour of the heating basins of a saltpan. The Fuencaliente saltpans, "Salinas Marinas de Fuencaliente", are a perfect example of the interplay of colours. A family of master salt producers built these saltpans in the last third of the 20th century and had the good fortune to be spared by the lava from the Teneguia volcano, which avoided the construction as it flowed to the coast.

The Salinas Marinas de Fuencaliente - the saltpans

Today, the salt produced here is of a very high quality, and great care is taken of the area. The site is also an important stop for migratory birds, giving the area a biological SSSI (Site of Special Scientific Interest).

The lighthouse marks the end of the Volcano path, Ruta de Los Volcanes. Most of this coastal platform was created by the 1677 eruption of San Antonio and the 1971 eruption of Teneguia. The abrupt nature of the platform shows where the lava reached the ocean.

The lighthouse is made of Arucas stone, brought to the island by sea from Gran Canaria. The old lighthouse was a welcome sight to sailors and travellers alike, but is now used as an exhibition space with a taller, but less aesthetically pleasing lighthouse taking over the traditional lighthouse role.
On returning back to our home for the next three weeks, all the equipment is prepared for the next day. Batteries, GPS and PDA's are charged, equipment is replenished and some of the equipment is disposed of to reduce contamination.

The samples are the split according to what they are needed for. In this case one sample is for Micro-Chromatography (µCG)
Now it is time to chill, eat and have a beer!

Just outside our little house is a little church where peaceful singing can sometimes be heard. When we arrived there was the Corpus Cristi (flower carpet) festival going on which was followed by the Transvulcanica race.

A very small snippet of the Corpus Cristi displays

Transvulcania winners plaques - this years was added while we were there

The Transvulcanica race is a mountain ultra-marathon that is 73.3km long, a cumulative elevation gain of 4,415m and a loss of 4,110m. They run from the southern tip of the island up and along Cumbre Vieja ridge following La Ruta de los Los Volcanes, around the rim of the Taburiente caldera, down to the coast near Tazacorte and inland to Los Llanos, and they are running on lavas and unconsolidated ash, lapilli and tuffs!

Every day is an adventure!

Buenas noches de La Palma!

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