Two-faced Kilauea volcano exposed
Hawaii's Kilauea volcano draws two million visitors every year but its photogenic lava fountains and rivers hide a more tempestuous nature.
Scientists say their latest research indicates that explosive eruptions have been far more common in the past than the gentle outflows seen today.
And they warn that a return to this more violent behaviour would require the permanent evacuation of large areas around the volcano.
Dr Don Swanson from the US Geological Survey's Hawaiian Volcano Observatory describes the latest findings to our correspondent Jonathan Amos.
07 Dec 2011