Inside the Volcanoes

New Lava Tube at the Hotel Royal Palm - Puerto Ayora, Santa Cruz Island

There is only one type of cave that, without doubt, you are sure to find not only on Earth but also on other planets: lava tubes. Wherever there are volcanic phenomena in the solar system, or even in other planetary systems, there certainly exist similar underground networks. These are caves that are formed by means of “construction” rather than by the erosion or dissolution of a pre-existing rock. For this reason, they are referred to as “syngenetic”, meaning that they have the same age as the rocks that enclose that void. Nowadays, vulcanospeleology is a recognised branch of exploration of the Earth’s subterranean world, with its own committee forming part of the International Union of Speleology. However, from the exploratory and scientific perspective, a great deal remains to be done. Often, volcanic areas – and, above all, large volcanos with active shields – are located in zones that are difficult to access. Lavic terrain poses substantial difficulties to those who want to traverse it; and often there are also eruptions to be taken into account, which are difficult to predict when working on a research project in these far-flung parts of the world. In 2015, we were developing a project for the exploration of a number of lava tubes identified via satellite images as being on the slopes of the Wolf Volcano on Isabela island (Galapagos). We had even flagged up the possible location for a base camp, but in the May of that year a major eruption wiped out that very area, destroying forever the caves that we had picked out and creating new ones in the process. Every volcano is a continuously evolving territory, a little like a glacier, but in this case the caves are formed by fire; and every new cave amazes us and takes our breath away, passing through its cooling phase, which offers up unexpected meta-stable concretions, themselves destined to disappear when the inside of the tube cools down. In these veins under the skin of volcanos we are discovering a lot about the formation of the Earth’s crust, the evolution of species and their adaptation to extreme environments. This is a frontier that remains little-known compared to classic karst caves. Dozens of lava tubes have been explored in Hawaii, Iceland, the Canaries, Réunion Island, Queensland, Vietnam, Japan and even in the great Italian volcano, Etna. But there are still places that are entirely unknown in terms of their fiery subsoil, such as the Galapagos (in large part), but also the remote archipelago of the Kerguelen Islands, a giant shield volcano that emerges from the Indian Ocean and runs towards the coasts of the Antarctic. Having explored tropical caves, glacier mills, sea caves, meanders in salt, abysses in quartzites, La Venta now wants to focus on this frontier. Looking from the Earth towards the other planets. Perhaps before the end of this century we may just manage to see an astronaut exploring a lava tube, like those described here, but under the volcanos of the Moon or even of Mars.

Small lava tunnel at the Volcan Chico, Puerto Villamil, Isabela Island