The Red Cross says the scale of devastation on the Pacific island could be immense.
Pressure waves from a volcanic eruption in Tonga at the weekend were picked up in the midlands.
Devastation has been caused following the eruption at sea which triggered a tsunami.
Pressure waves were picked up by Irish weather stations 16,0000 kilometres away.
Met Éireann says its Mullingar and Valentia stations recorded a jolt in the pressure readings associated with the wave.
The Red Cross says the scale of devastation on the island of Tonga could be immense.
The charity estimates that up to 80,000 people on the Pacific island might be in need of things like shelter, and essential supplies.
Sky's correspondent Siobhan Robbins says Australia and New Zealand are among the neighbouring countries providing help:
One British woman's been reported missing.
Her brother says waiting for news about her is "excruciating".
Angela Glover, an animal charity worker, and her husband James haven't been seen since their coastal home was hit by the waves on Saturday.
Nick Eleini says he just wants to know what happened to his sister: