“The eruption shows that life on the island continues, although from a human perspective it is a disgrace”
Just arrived on the island of La Palma with a team from the Complutense University of Madrid (UCM), the geologist Eumenius Ancochea Soto (Madrid, 1950) heeds the call in extremis, before entering a territory without cover ravaged by the passage of lava flows.
The eruption of the Teneguía volcano in 1971 surprised him studying for a degree at the Faculty of Geology in Madrid and he could not travel
“We are all here to work on whatever is required at all times,” he forcefully affirms to SINC while waiting to receive the distribution of functions. For the professor of the Department of Mineralogy and Petrology of the UCM, this is the second eruption that lives on La Palma, although the first – that of volcano of Teneguía in 1971–, he was surprised by studying at the Faculty of Geology in Madrid and was unable to travel.
“The students stayed in Madrid and the media was something else. We lived it because our teachers went to the island and they were the ones who controlled the monitoring of the eruption ”, he recalls.
What did you learn from those teachers?
As a student, I experienced that eruption from a distance, but when I finished my degree I continued working with those who had been there. I know all of them and have worked with them all my life.
Now it’s your turn. What tasks will you perform as a geologist at Cumbre Vieja?
Our team will focus on the most geological functions within an order, that is, we will get closer to seeing how the flows are evolving, their speed, etc. We do not work with earthquakes, but we have come to do what we can to be useful.
Will they collect samples for this?
We do not know yet. Who coordinates everything is the National Geographic Institute and we are at your disposal. The first day we dedicated ourselves to making observations of the crater and its explosions, not the streams. We took samples of lapilli – small fragmented rocks blown into the atmosphere.
The team of geologists of the UCM in La Palma. / Photo courtesy of Eumenio Ancochea
We are all here to work on whatever is required at all times
This is a unique opportunity for you. Can they somehow corroborate decades of study?
As here on La Palma there has not been an eruption in 50 years, from a geological point of view you do not dedicate yourself as much to following eruptions. This has been a coincidence. For this reason, what our group from the Complutense has studied has been to see how this and the other Canary Islands have functioned volcanically throughout their history to get an idea of what could happen.
In this sense, what does the new eruption indicate about the evolution of La Palma?
First, that it is still active and that it continues to grow. It is their normal development. Each of the Canary Islands may have been formed by hundreds of thousands of eruptions. So, from the geologist’s point of view, one more eruption shows that life on the island continues. From a human perspective it is an absolute disgrace, and the scenes here are terrifying for personal injury, but for geologists, who move on a scale of hundreds of thousands or millions of years, it is only a tiny dot in the evolution of the island.
Yes, but in the end between one eruption and another on La Palma “only” 50 years have passed, a much shorter period of time at a geological level …
True, but it is the normal one. If an eruption has a pouring thickness of 10 meters and one occurs every 50 years, how long does it take to form an island like La Palma? You can get an idea, and that the current eruption has not covered the entire surface of the island. La Palma rises on an ocean floor 3,000 meters deep and is almost 2,500 meters high. In total there are about 5,500 meters of pouring and to form them many eruptions are needed. So one every 50 years is a normal rate for the evolution of the island.
If an eruption has a pouring thickness of 10 meters and one occurs every 50 years, how long does it take to form an island like La Palma?
But on a human level they continue to surprise us.
Well, when we got to the island we met a peasant who told us that he was born in 1942, and therefore this was the third eruption that he had lived. He lived one at 7, 29 and 79 years old. So there are people of a certain age, over 72 years old, and from La Palma who, like him, have experienced three eruptions. They know the damage it causes and how bad it is, what happens is that when 50 years pass you forget. You think it will never happen to you.
But it happens and the lava tongues destroy entire houses …
Already, in the Teneguía eruption there was more luck because it happened in an area of the island where there were no houses. The destruction it caused was total, but it did not cause damage to people’s farms. Obviously yes to the one who passed through his land, but there were no houses like now, nor destroyed as he is doing now. However, that of the San Juan volcano in 1949 was more similar to this. But at that time, the island’s population density was much lower than it is now.
It refers to the power of destruction, but in terms of explosiveness, they are all three of the same style, right?
Yes, they are very similar. The issue is that we Spaniards have lived on the islands for about 500 years, so of the eruptions that occurred in pre-Hispanic times we have no data or the effects they had on the population of the Guanches. From this island we only have data from seven eruptions and with that we can say little. What we can say is that they are all very similar and that it was to be expected that if an eruption occurred it would be something similar to this one, although we all expected it to happen further south in an uninhabited area. But there has been bad luck.
Like this one, is it to be expected that others will be produced in the coming decades?
On the island of La Palma we calculate that on average one occurs every 53 years, but there was a period of more than 230 years in which there was none … And yet, between 1949 and 1971, 22 years passed. Therefore, we cannot know at all. Now maybe it will happen again that for two centuries there will be none or in 20 years there will be another.
On the island of La Palma we calculate that on average one occurs every 53 years, but there was a period of more than 230 years in which there was no
Will there be more means by then so that the population is more prepared?
Of course, it is no longer just to notify people in advance, perhaps they would have to take it into account at the time when a territorial planning is carried out in a town hall. But it is very difficult because you cannot forbid people to build their houses, and cultivate their farms. Although in the Peninsula we experience it less, in the Canary Islands in general they know the problem they have and for many years that has been planned. Emergency measures and escape routes are working perfectly. So many people are working on this crisis that they seem to know how to handle it. That was not seen at all in 1971. Here the media capacity that is involved with the authorities draws attention for the better.