The Cumbre Vieja volcano , located on the island of La Palma, is part of the Canary Islands volcanic complex and was primarily responsible for the 2021 eruption that captured global attention. This volcano is considered Strombolian, but many of its characteristics and behavior are also similar to those of Hawaiian-type volcanoes. In this article, we will explore in detail the characteristics, origin, and eruptions of Cumbre Vieja.
Key features
The Cumbre Vieja volcano is one of the most impressive of its kind in Spain, with an elongated and steep relief on the west side of the island, while the east side has gentler slopes. This volcano has been under constant surveillance due to the frequent seismic activities recorded in the area, which could indicate future eruptions.
Cumbre Vieja's magma is highly viscous and moves slowly, making it prone to building up internal pressure, increasing the risk of explosive eruptions that could be dangerous for nearby populations. However, throughout its history, the volcano has alternated between explosive and effusive eruptions.
It is important to mention that, in addition to the threat of lava flows and toxic gases, Cumbre Vieja's eruptions have generated earthquakes associated with volcanic activity. These earthquakes are a key element in monitoring any signs of upcoming volcanic activity. The island of La Palma is also a major tourist destination, and many people visit Cumbre Vieja for hiking. However, it is vital that visitors follow the instructions of local authorities for their safety.
Formation of the Cumbre Vieja volcano
The Cumbre Vieja volcano was formed progressively over several volcanic eruptions dating back more than 1,2 million years. As a shield volcano, it built up its structure from layers of fluid lava and scoria. Its elongated shape on one side and steeper on the other is characteristic of its type.
The volcano is composed mostly of basalt, a dark, dense rock that, when emitting lava, flows rapidly across the ground. It is also composed of trachyte, a lighter rock. These compositions are fundamental to understanding how magma flows and how a volcano like Cumbre Vieja can generate both explosive and effusive eruptions.
The geological process that gave rise to Cumbre Vieja is associated with tectonic activity in the Canary Islands region. As part of the volcanoes that form on a moving tectonic plate, the Canary Islands have an active geological history, and Cumbre Vieja has been one of the most notable witnesses of this process. Specifically, the seismic and volcanic activity of La Palma is due to the volcanic ridge that crosses the island from north to south.
Eruptions of the Cumbre Vieja volcano
Cumbre Vieja has recorded multiple eruptions throughout its history, some of the best known being those of 1949, 1971 and the most recent one in 2021.
The 1949 eruption marked a significant event in the history of Cumbre Vieja. On that occasion, a large fissure opened on the volcano's southern flank, releasing lava that flowed into the sea and led to the formation of a new peninsula on the island. This event was accompanied by explosions and ash emissions that affected nearby towns.
In 1971 , a new fissure on the volcano's northern flank triggered another major eruption. Lava flowed, destroying infrastructure and devastating crops. This eruption reinforced the myth of Cumbre Vieja's destructive power.
The most recent eruption, in 2021 , was particularly devastating, lasting 85 days and affecting vast areas of the island. Lava flows covered more than 1200 hectares, destroying 1.676 buildings and severely impacting the local economy. The most striking aspect of this eruption was its duration and the intense gas emissions, which exceeded two gigatons of sulfur dioxide.
During the eruptions, collaboration between local authorities and scientists enabled a rapid response to protect populations. Alerts were issued, and evacuations were carried out in an organised manner to minimise human losses.
what kind of volcano is it
The Cumbre Vieja volcano is known as a shield volcano . Shield volcanoes are characterized by their broad, gentle slopes, formed almost exclusively by the accumulation of fluid lava. This type of volcano is commonly found in geologically active areas such as Hawaii, and in the case of the Canary Islands, it is due to the volcanic activity occurring along the Cumbre Vieja Ridge.
Volcanoes like Cumbre Vieja are predominantly effusive, meaning that their eruptions occur through continuous lava flows, rather than pyroclastic explosions. The lava emitted by Cumbre Vieja is composed primarily of basalts, a volcanic rock rich in iron and magnesium, which flows easily over the ground. This type of eruption can cover large areas of land in relatively short times.
The type of activity observed at Cumbre Vieja includes both Strombolian-type eruptions, alternating explosions and lava flows, and Hawaiian activity, with continuous lava fountains. During the 2021 eruption, this mixed type of volcanic behavior was observed.
In addition to volcanic activity, Cumbre Vieja is also an important point for the study of seismic activity. The accumulation of magma in the subsoil causes earthquakes that, in many cases, anticipate eruptions. This is one of the reasons why constant monitoring of seismic activity in the area is essential to predict future eruptions.
The impact of the 2021 eruption
The 2021 eruption was one of the most devastating events in the recent history of the Canary Islands. With a total of 85 days of activity, it exceeded all initial predictions. One of the most notable effects was the creation of lava deltas on the west coast of La Palma, which expanded the island's land area by more than 43 hectares to the south and 5 hectares to the north.
The material damage was considerable. The lava destroyed more than 1.570 homes and destroyed more than 370 hectares of crops, affecting mainly banana plantations, one of the island's main economic resources.
Another significant phenomenon was the emission of gases , which reached dangerous levels, forcing the evacuation of many more people and affecting activities such as aviation, as the island's airport remained closed for days due to volcanic ash. Although volcanic tremor subsided in the final stages of the eruption, the area still experiences emissions of gases such as sulfur dioxide, which renders some areas uninhabitable today.
The response of the authorities and the scientific community was swift and coordinated, with more than 500 accredited scientists supervising the activity, and more than 7.000 people evacuated from high-risk areas. Thanks to these efforts, human losses were zero, although economic losses exceeded 400 million euros.
The importance of volcanic monitoring
One of the most important aspects of managing an active volcano like Cumbre Vieja is the constant monitoring of its activity. Throughout history, volcanological research has helped predict eruptions using advanced techniques. The study of seismic signals is one of the most widely used methods to anticipate volcanic activity, along with the analysis of ground deformation and the gases emitted.
The use of drones and satellites has allowed scientists to obtain real-time information and accurately track volcanic activity. This was crucial during the 2021 eruption, when more than 2.800 drone flights were conducted to monitor the volcano's evolution and the damage caused by the lava in detail.
Another important study is the chemistry of the gases emitted. Sulfur dioxide (SO2) is one of the main volcanic gases, and its release in large quantities during an eruption can provide key information about the amount of magma that is rising to the surface. In the case of Cumbre Vieja, more than 10 gigatonnes of SO2 were recorded during the climax phase of the 2021 eruption.
The future of Cumbre Vieja
Volcanic activity on the island of La Palma is a topic that has been studied for decades. Although the 2021 eruption has ceased, scientists are keeping a close watch on the area as the volcano continues to show signs of residual activity. It is believed that the degassing process that is still occurring in the area could last for months or even years.
The eruption has also demonstrated the adaptive capacity of communities living in volcanic risk zones. Although many people have lost their homes, reconstruction plans are already underway, with support from both local and international governments. New infrastructure and routes are being created to accommodate the changes in the terrain caused by the lava, and the creation of natural parks to take advantage of the new volcanic deltas that have formed is being promoted.
On a scientific level, the Cumbre Vieja eruption has provided an invaluable amount of data that will allow for improved early warning systems for future eruptions not only in the Canary Islands, but in other parts of the world where active volcanoes represent a potential risk. Continued cooperation between national and international research centres will remain key to mitigating the risks of the volcano in the future.
The Cumbre Vieja volcano will continue to be one of the most studied and monitored volcanic formations, not only for its destructive potential, but also for the crucial geological information it provides for understanding volcanic activity worldwide.