Lanzarote is best known for the 300 plus volcanoes that define the islands terrain. The result of geological activity that has spanned many millions of years – and which over time has enlarged the surface area of Lanzarote by approximately 174kms sq – equivalent to around one quarter of its current size. But what caused these volcanoes to erupt in the first place? And what is the likelehood of them stirring again during your holiday on the island?
Hot History
Lanzarote has witnessed enormous volcanic activity over the last four million years and most of the volcanoes in the northern half of the island precede the more famous domes of Timanafaya by many centuries. Monte Corona, for example, the towering mountain at the very northern end of Lanzarote is thought to be at least five thousand years old.
And the underground tunnel formed by lava flowing down from the crater of Monte Corona has formed the world’s longest subterranean lava tube, stretching some seven kilometres down to the sea and incorporating not only the caves at Cuevas de los Verdes but also the tunnel which now houses the Jameos del Agua.
Fault Lines and Hotspots
Volcanoes tend to form at the fault lines of tectonic plates – the earth’s crust – where these plates meet each other and consequently become thinner or more stretched.
At these points fissures or cracks in the earth’s surface appear and molten lava, ash, gas and other debris is expelled. However, there is also volcanic activity in areas of the world where there are no converging plates, such as in Hawaii, a phenomenon caused by a ‘hotspot’.
Each volcano normally has a large magma chamber at its base, which fills up with gases and molten lava over time, eventually creating such pressure that the material is forced upwards through the bedrock and erupts at the surface through a vent. The eruptions create new layers of volcanic material around the crater, leading to the volcano’s gradual growth in size.
There are several types of volcano, including shield volcanoes, lava domes, cinder cones and stratovolcanoes. The most notable differences between these types are that shield volcanoes tend to be longer and flatter than the typical dome shape, whilst lava domes normally have slower flowing liquid lava eruptions. The third type, the cinder cone, normally only erupts once, spewing out ash and cinders.
Stratovolcanoes are potentially the most dangerous to humans, as it is this variety that produces a pyroplastic flow of choking gas and dust that engulfs the surrounding land extremely quickly, as was witnessed when Pompeii was swallowed by Mount Vesuvius. Stratovolcanoes are usually very large and combine eruptions of both molten lava and gas-dust clouds.
Last but most certainly not least, is the supervolcano, of which the caldera in Yellowstone National Park is a prime example. As the name suggests, these are giants which have the potential to affect the world’s climate when they erupt, such is the volume of material expelled into the atmosphere.
Lanzarote’s Volcanoes
The vast majority of the volcanoes to be found on Lanzarote are lavadomes and were formed during the six year period of violent activity between 1730 and 1736. With further major eruptions engulfing the island in 1824, which extended the lava flow in a south-westerly direction.
Such a prolonged period of activity meant that the island increased its land mass by 174 square kilometres. Eleven villages, such as Santa Catalina and Maretas were entirely swallowed up by the eruptions of 1730-36, leaving over 500 hundred people homeless.
The village of Santa Catalina is more or less where the highest peak within Timanfaya now stands, Pico del Fuego. The tour buses which wend their way through the park actually climb up to the top of this peak and stop so that visitors can view the crater and the incredible landscapes visible from the mountain.
Since this infamous period of eruptions the volcanoes have been in a dormant phase, with little seismic activity occurring. As visitors to the Timanfaya National Park will discover, the intense temperatures that exist just below the earth’s surface are still very much in evidence though. As the experiments conducted by staff at the Park, plus the open volcano fuelled grill at the El Diablo restaurant amply illustrate.
The land which now forms Timanafaya National Park had, up until that time, been the most fertile area of Lanzarote. Thus the local inhabitants, although none of them died, were not only driven from their homes during the eruptions but also had their livelihoods destroyed in the aftermath. Which is why so many Lanzaroteños left the island altogether, seeking new lands where they might be able to recover their fortunes. Many emigrated to Cuba and Venezuela (a process documented at the fascinating Emigration Museum housed in the Castillo de Santa Barbara, which overlooks former island capital Teguise).
It was only in subsequent decades that farmers on the island discovered the beneficial aspects of planting vines and other crops in the volcanic gravel, known as picon, covering much of the island’s surface. This method of cultivation is known as enarenado, where crops are planted in a layer of picon, which assists in the retention of moisture and reduces evaporation.
Future Eruptions?
It is extremely unlikely that any of Lanzarote’s volcanoes will erupt without warning. Partly as this is preceded by tremors and other measurable activity just below the earth’s surface, usually weeks or months before an eruption.
The volcanoes are monitored by extremely sensitive equipment which measures seismic activity at various points around the island – at the Centro de Visitantes e Interpretación in Mancha Blanca and the Casa de los Volcanes at the Jameos del Agua, as well as within the National Park itself.
In addition, the type of volcano which Lanzarote is home to is typically a lava dome. Meaning that there is no risk of a sudden gas cloud engulfing unsuspecting visitors, such as occurs with a pyroplastic flow. The lava streams which emerge from the volcanoes here are slow moving, giving ample time to get out of their path.
