A 16-acre lava shelf from the Kilauea volcano flow collapsed into the sea Thursday, sending steam plumes up to 1,000 feet into the air, scientists have reported.

The piecemeal collapse of the East Lae'apuki shelf also generated strong seismic signals that were recorded at the U.S. Geological Survey's Hawaiian Volcano Observatory, officials said.

The contact of the still-hot lava shelf with cold ocean water sent steam plumes, blackened with rock dust, shooting into the air.

The collapse began from the east at about 2:45 p.m. on Thursday and continued until at least 7 p.m.

By nightfall, only thin slivers of the lava bench, some still incandescent, were left clinging to the sea cliff, the observatory said in its daily report Friday.

The resulting explosions threw fist-, volleyball- and basketball-sized rocks up to 400 feet inland. There were no injuries.

Scientists on Friday were studying time-lapse photographs of the collapse to learn more details about the changes to the landscape.

Observatory officials said no active lava flows had been seen at the East Lae'apuki area since mid-March, but temperatures of the lava remained very hot just a few meters below the surface.

Lava shelves occur when cooling lava from a volcanic eruption begins to harden as it nears the ocean's edge.

However, the ocean waves frequently undercut the shelves, leaving them vulnerable to collapse.

Kilauea has been in nearly continuous eruption for more than 24 years, most of the time from the Pu'u 'O'o vent in the east rift zone.