Mt. Erebus is one of the largest active volcanoes on Earth. It reaches nearly 4 km above sea level, and is renowned in volcanological circles for its persistently active lava lake, which is sited in the summit crater. The hot volcanic gas steaming from Erebus does more than fuel for the lava lake. Hot gasses traveling up through cracks and fractures in the volcanic rocks surrounding the Erebus summit have created an intricate system of ice caves all over the mountain.
