A Six-Year Eruption's Lingering Heat
Between 1730 and 1736, Lanzarote experienced one of the largest basaltic fissure eruptions in recorded history. For 2,055 days, a series of over 100 volcanoes erupted along a 15-kilometer fissure, spewing an estimated 3 to 5 cubic kilometers of lava and ash. This event buried about 200 square kilometers of the island, a quarter of its surface, under a thick crust of basalt. The parish priest of Yaiza, Andrés Lorenzo Curbelo, chronicled the event, describing how fertile villages were lost as the earth split open.
Nearly 300 years later, the thermal aftermath of this eruption persists. This geothermal anomaly makes the ground exceptionally hot just below the surface. At a depth of 13 meters, temperatures reach between 100 and 600 degrees Celsius. Even just 10 centimeters down, the temperature can be 277°C. This residual heat is caused by a magma body that still sits beneath the island, slowly cooling. Park staff demonstrate this heat with dramatic effect: dry brush dropped into a shallow pit bursts into flame, and water poured into a borehole erupts instantly as a geyser of steam.