One of the consequences of the eruptions that have occurred on this Spanish island is the spread of sulfur dioxide to Africa and the Caribbean. Another is the change that can occur in marine fauna due to lava that collided with the sea.
The tons of ash that the Cumbre Vieja volcano has emitted since the eruptions began on September 19 is not the only environmental impact it has left. One of the most widespread effects is sulfur dioxide, which is the colorless gas released by the volcano.
On the one hand, sulfur dioxide, or SO2 by its molecular formula, is used to calculate how much magma the volcano has emitted. Thus, if SO2 is constantly decreasing, it is a clear indication that the eruptions will end.
But the consequences of this gas go further. The Canary Islands Volcanological Institute (Involcan) estimates that Cumbre Vieja has emitted at least 250,000 tons of carbon dioxide. This amount is so great that it has reached North Africa and the Caribbean, specifically to Puerto Rico and the Dominican Republic, as detected by the Copernicus / Sentinel Satellite of the European Space Agency.
And it is that the sulfur dioxide traveled with the same air currents that make the dust of the Sahara reach the Amazon to become nutrients, according to what the Caribbean Astronomy Society.
At the time, the Department of Natural and Environmental Resources (DNER) of Puerto Rico considered that the island air was unhealthy as the sulfur dioxide cloud passed. If a person is exposed to high amounts of this gas and for a long time, their respiratory system could become inflamed and the eyes could become irritated. In ecosystems, the damage it produces is that it degrades chlorophyll and reduces photosynthesis, which can affect countless species.
That is why the production of sulfur dioxide and dioxide is controlled, especially when burning fuels, which is the largest producer of these gases, even above volcanoes.
On the other hand, studies have shown that when volcanoes emit large amounts of carbon dioxide, this helps reduce global warming. For example, with the 20 million tons of carbon dioxide emitted by the Pinatubo volcano in the Philippines in its 1991 eruption, the earth cooled to about 0.5 degrees Celsius. But it is estimated that the SO2 emitted by the La Palma volcano is still too low to have a similar effect.
The arrival of lava to the sea impacts marine ecosystems
Another of the most visible environmental effects left by the volcano for now occurred when the magma first touched the sea water, on September 28, at Los Guirres Beach in the municipality of Tazacorte. The collision of temperatures between the more than 1,100 degrees of the volcanic rocks and the close to 20 degrees of the water caused the magma to solidify and become a piece of land attached to the island. This land measures for now about 32 hectares. This is called a lava delta or fajana, as it is known locally.
In addition, there was a chemical shock that caused a cloud of carbon dioxide, carbonic acid and sulfuric acid that was in the lava to rise, added to the sodium chloride from the sea salt. Already in the water, magma causes carbon dioxide to increase and oxygen to decrease, a combination that can be deadly for many species.
It is still too early to know how much the Cumbre Vieja lava has affected the marine species of the Canary Islands. The ship Ramón Margalef from the Spanish Institute of Oceanography monitored the situation from the sea and collected 500 liters of water to analyze this and other possible effects.
However, there are indications of what may happen. On the one hand, the NGO Ben Magec Ecologists In Action told RFI that part of the marine fauna disappeared days before the lava arrived “as if it had known something was going to happen.”
In addition, there are studies such as the one carried out by the Institute of Oceanography and several Spanish universities on the consequences of the eruption in October 2011 of the underwater volcano of El Hierro, in the Canary archipelago. The analysis revealed that the magma disturbed the marine ecosystem, reducing biodiversity and causing the composition of some species to change. Although not all the news is negative, as the lava caused the phytoplankton to increase.
What is certain is that only with time will it be known for sure what consequences the prolonged eruptions of the Cumbre Vieja volcano will have on marine fauna and ecosystems.