LA PALMA’S ERUPTION AND ITS EFFECTS ON OUR ATMOSPHERE
Volcanos are arguably one of the most terrifying natural phenomena known to humankind and probably for this reason their impact has been well documented over hundreds, if not thousands of years. Their destructive nature makes us unable to look away as we are witness to large swathes of land and sea transformed into a mountain or two of volcanic rock and ash. A force from deep within the earth’s mantle which has claimed thousands of lives makes volcanic eruptions very deadly. And it’s with great relief that no one has lost their life to La Palma’s new addition. However, apart from the direct material impact the volcano is having on the islanders, there is also a lesser known one which comes from the emission of gases emitted from the volcano. Sulphur dioxide emissions can really make the impact of eruptions reach a global scale. And what has happened in La Palma can, potentially, be no different.
It might be easy to detach ourselves from other people’s nightmares which involve rivers of lava flowing down the street and sweeping away everything dearest to you. Happily, for most of us who live in Europe, we don’t really have to contend with volcanic activity. Yet volcanos can have far-reaching effects which make cooperation between everyone born from necessity, if not altruism sadly. It’s been quite embarrassing to listen to a wide spread finger pointing such as “they shouldn’t have built next to a volcano in the first place!” I would like to remind the world that everyone who lives in the Canary Islands is literally standing on a by-gone eruption. This doesn’t mean that volcanic activity is present on all islands however this is so in La Palma. You can’t really tell when magma will strike and form a volcano as it seeks the path of least resistance to break out of the mantle and release the pressure built from deep below the crust. Bluntly put, it is rare that lava “strike twice” from the same caldera, we can only calculate a rough area making impossible to avoid building in a manner which avoids future volcanic activity. The Canary Islands are literally built by a series of volcanic eruptions from a “hot spot” deep below the Atlantic, creating a chain of islands in a south-west to north-east direction. This means that the most easterly islands of Lanzarote and Fuerteventura are also the oldest, with La Palma and Hierro being the youngest islands of the archipelago. Volcanic activity is, obviously, a reality in La Palma. This also means that it’s anyone’s guess where the new volcano will form though recent eruptions do point towards the Southern side of the island, which is famous for having seen many eruptions with evidence still mostly visible today. AKA Teneguía Volcano 1971.
The ground in La Palma had been shaking for about a month, with localised “swarm” earthquakes that could be felt in the whole south half of the island. The epicentres of these slowly raised from the mantle and, on live TV past 15.00 hours on the 19th of September 2021, the newest volcano to hit the Canary Islands had begun. The scale of the destruction has also made it the worst volcano to hit the Canaries since records began in the XV century (after the Castilian conquest of the archipelago). In over a month of activity since mid-September nearly three thousand buildings have been razed, hundreds of these were illegal dwellings which means many are ineligible to receive government or private compensation for the loss. So spare a thought to the communities hit, with many whole families losing a few houses, their local school, church… the utter destruction is truly breath-taking and merits our full solidarity. It is always the poorest who are hardest hit, with eye-watering house prices meaning that deeper foreign pockets will populate the area in the future. However, it is the not so visible effect which can have the hardest hitting impact upon life on this planet and which also merits our attention: the gases released by the eruption.
Volcanic eruptions emit four distinct gases which can have effect on our planet’s atmosphere. Firstly, the usual suspects of global warming; carbon dioxide and monoxide. I won’t dabble on the impact of these gases, but some volcanoes can emit huge quantities of these, yet nothing compared to the scale of human activity, however this will create further pressure on us to reduce our overall emissions. It’s the sulphur dioxide (SO2) and hydrogen sulphides and halides which are the most intriguing gases. With SO2 converting into sulfuric acid aerosols which block solar radiation and depletes our ozone. Most fascinatingly however, their overall effect cools the planet by absorbing solar radiation. This localised cooling can be devastating to farmers as crop failures in far flung areas have been linked to prior historic eruptions. The influence that volcanos have on our weather system has been well studied, well documented and is undeniable. Thanks to the local Canarian volcanism institute INVOLCAN and scientists in the EU’s Copernicus programme the SO2 emissions are being monitored. Just over fifteen days from the 19th of September to the 5th of October 2021, the calculated emissions of SO2 were approximately at 250.000 tonnes into the upper atmosphere. The effect of the cooling is unknown. However, at this rate half a million tonnes of SO2 are being emitted monthly. This is already a big problem for those living on the island with unsafe levels of exposure to SO2 recorded in Los Llanos de Aridane and neighbouring areas. The effect of the cooling will still have to be felt, let’s hope it hits somewhere in the middle of the ocean.
Volcanos have a spectacular capability for destruction which has captured our imagination however it might well be the suddenness of a volcanic eruption which gives this phenomena a real fear factor. It’s this awareness that a “blink of an eye” moment can really change anyone’s life that is bringing many islanders and those further out to reach in and help the Palmero’s overcome the disaster. Many people may scoff at those who live on active volcanic islands however it goes without saying that nobody on a volcanic island is safe – though fear not, most of the Canaries are free from any volcanic activity, no one can say the same of those who live on the banks of a river are safe from floods. In the end, as with natural disasters, it will be those without pocket who will suffer the most, with pitiful government grants of about 30,000€ per house lost – a fraction of the over 200,000€ a house is worth on La Palma, and two villages trapped under tonnes of petrified magma. Isn’t it typical that ministers are already cooing over the tourist value of such a worrisome phenomena?