The death toll was expected to rise as reports filtered in from the most remote locations of the isolated Santa Cruz Islands group, which is part of the Solomon Islands.
Damage to a key airport on the worst-hit island of Nendo (also known as Santa Cruz Island) prevented aircraft from bringing relief supplies in the aftermath of the disaster.
The relief agency World Vision estimated that 3,500 people were displaced by the tsunami, which destroyed hundreds of homes.
Four villages on Nendo were hit by the waves, with two receiving severe damage. Other areas of the Solomon Islands did not appear to have been seriously affected.
World Vision said some houses in the town of Venga were shifted 30 feet by the force of the surging water and almost all the homes in Nela village were washed away.
The initial quake struck at 12:12 p.m. local time beneath the Coral Sea just to the west of Nendo. The resulting uplift of the ocean above created the tsunami, which struck Nendo moments later.
Japanese authorities say ocean rises of up to 15 inches were reported in the country’s Isu island chain, about 175 miles south of Tokyo.
A tsunami warning had briefly been issued for New Zealand, Australia and other Pacific island nations during the moments following the massive quake. w