Gjávella is a fissure outflow west of Mt. Hrútafjöll. Occasionally during the Krafla fires which raged from 1975 to ‘84, lavas flowed into fissures and faults. These became conduits enabling the lava to propagate for long distances, sometimes with associated steam explosions and rock pitching. During an eruption in July 1980, all the lava originating at Snagaborgir, plunged into a fissure for 17 hours. The lavafall's edge was measured to be about 170 m. Occasionally lavas would disappear into fissures and subsequently reappear, flowing out some distance away from the original entry point. An example can be seen west of Mt. Hrútafjöll. It is not known how far south it actually poured in. This also occurred during the Hverfell fires about 2700 years ago. The Gjástykki graben had been extending for 10,000 years without any lavas smoothing the fissures over. Lavas from Éthólar then flowed in freely and subsequently reappeared from a fissure located not far from the settlement of Kelduhverfi at a place called Kerlingarhóll. This lava (Skinnstakkahraun) covers an area of about 13 km2.