You are standing at the lip of the main vent. Fallen rocks cover the actual opening through which lava erupted 17 times. Each episode of the eruption played out differently. Some went on for days while others lasted only hours. Molten rock sometimes poured from the vent in a rolling boil. At other times lava burst skyward to form towering fountains in a matter of seconds.

Note the variety of colors in rocks around the vent. In a process similar to the way water rusts a nail, volcanic gases oxidize iron-rich minerals in lava, creating shades of red, purple and brown in the rocks.