THE SINKHOLE THAT split apart a Monaghan GAA pitch appears to have been caused after pillars in an old gypsum mine collapsed, a geological expert surveying the area has said.

A team of specialist geological experts working on behalf of the Department of Communication, Climate Action and Environment, and liaising with Monaghan County Council, are carrying out surveys in the area to decide whether further sinkholes are possible and what can be done to salvage the land.

One of those experts Koen Verbruggen, told Morning Ireland that there are former underground mine workings located underneath the GAA pitch and around Knocknacran. The mines were used since the 1940s to obtain gypsum, a substance used to prepare plaster, chalk, and wallboard, and which is also used as a fertilizer.

“There are levels of old mine workings in the area; they are well-mapped and are known about. What has happened is in some of those old mine workings, it appears that pillars which are used to support the mine route may have collapsed at depth… and there’s a sag at surface resulting in this fracturing and sinkhole.”

 He said that the sinkhole affects a radius of 120 metres, and that the surveys are confined to a 2km zone.

“There’s no evidence of further collapse – although there is evidence that sinkholes have developed along the fractures, this is to be expected as settlement occurs.”

But, when asked directly if there will be more collapses, he added:

“The short answer is we don’t know if there will be more collapses. The only thing is to monitor the situation, usually it’s one collapse and that will be the end of it. If there are further collapses, it’s likely to occur quickly.

He said that all tests showed that there was no spread, and that it’s a positive that there’s no critical infrastructure built over the mine workings. “This is an area that’s largely fields… there are no hospitals or anything.”

The Magheracloone GAA Club that’s had to evacuate its location because of the split earth said it wouldn’t be able to return “for a number of years”. When asked about whether they could return, Verbruggan said:

“I don’t know the answer to that, but not based on the photographs I’ve seen.”