SERIOUS damage caused by sinkholes is rare in Ireland but the phenomenon itself is "very common" according to experts.
There are about 6,000 examples here, the Geological Survey of Ireland (GSI) estimate.
Dr Caoimhe Hickey, a GSI hydrologist, has reported that sinkholes (also known as dolines) are found in karst landscapes formed by rocks that are easily dissolved in acidic water.
She said that half of the country is underlain by a limestone, saying it is "an important aspect of the Irish landscape".
Sinkholes are formed in two ways -- slow solutional removal of the rock from the surface downward, or a sudden collapse of overlying rock and material into an underground cave.
It appears in the case of Tramore that the extreme waves battered the rock underneath Strand Road, causing the collapse of the road.
Dr Hickey highlighted a sinkhole in Co Roscommon and another in Cork where a cow was trapped at the bottom of a collapsed doline which opened up from under it.