WELLINGTON, New Zealand — The tsunami that killed more than 200 people in the Sämoan islands and Tonga earlier this year towered up to 46 feet high — more then twice as tall as most of the buildings it slammed into, scientists said today.

New Zealand scientists studying the size, power and reach of the tsunami as part of efforts to guard against future disasters said they found up to three destructive waves were caused by the magnitude 8.0 undersea earthquake in September.

The massive waves that struck Sämoa, American Sämoa and Tonga totally destroyed traditional wooden buildings, many of them singly story, along the coast while reinforced concrete buildings sustained only minor damage, said Stefan Reese, a risk engineer with New Zealand's National Institute of Water and Atmospheric Research.

The waves were up to 46 feet high, Reese said. The scientists measured watermarks on buildings and trees to help confirm the wave heights.

"In some areas there was virtually nothing left" after the waves reached up to 765 yards inland, Reese said.

Wide reefs saved some villages by helping to reduce the waves' height to about 10 feet, Reese said.

The Sämoan quake created a sea floor fault up to 190 miles long and 23 feet deep.