Explosion in Hawaii volcano could be first of larger blasts

(Reuters) - A fairly large explosion in Hawaii's erupting Kilauea volcano on Wednesday is likely the first of a series of larger explosions that could begin to throw rocks from and ash from the crater, the U.S. Geological Survey said. A small earthquake may have caused rockfalls into the crater and prompted Wednesday's explosion from the lava lake surface that shot projectiles out of the rim, said Tina Neal, the scientist in charge of the USGS Hawaiian Volcano Observatory. "This is the first of perhaps more events like that to come," Neal said on a conference call. "It's too soon to say we will see any cessation of activity in the lower east rift zone," she said of fissures oozing magma out of the east flank of the volcano that has destroyed 36 structures and caused the evacuation of around 2,000 residents. "There's still quite a fair bit of magma under the ground that's available to erupt," she said of fissures which have now grown to number 14. "If the lava continues to recede we may move into a period of these steam-driven explosions," she said of chances of explosive eruptions in the crater if water begins to mix with magma. (Reporting by Andrew Hay; Editing by Sandra Maler)