Volcano spews ash, lava on Big Island

The world's largest active volcano spewed some ash and lava Monday, and officials warned residents of Hawaii's Big Island to prepare for the possibility of a larger eruption.

The U.S. Geological Survey warned the island's 200,000 residents that an eruption of Mauna Loa “can be very dynamic, and the location and advance of lava flows can change rapidly.”

The eruption began late Sunday night in the summit caldera of the volcano on the Big Island following a series of closely spaced, fairly large earthquakes, said Ken Hon, the scientist-in-charge at the Hawaiian Volcanos Observatory.

Magma moved to the surface, although lava flows were contained within the summit area and weren't threatening nearby communities.