The Timanfaya eruptions belong to the fissure category which means an enormous fissure several kilometres long opens up allowing vast amounts of lava to emerge in the form of molten streams. This lava fills up depressions in the ground, levelling out the terrain to leave an almost horizontal surface. Cones form from the accumulation of volcanic material around the emission areas. Lava flows dominate the landscape, despite the sites of large amounts of cones and numerous eruption exits. An endless amount of lava tonnes sprouts from craters which join up intermingling with each other to form an immense sea of lava which occupies an entire quarter of the central part of the island. The lava flows stretch all the way from the volcanoes to the distant coastline reaching up to 20 kilometres in length at certain points. Upon entering the sea, they caused a gigantic columns of vapour to rise. The lava mass forcing the waters to recede, thus considerably increasing the surface area of Lanzarote.