The couple were joined by John's parents Noel and Carol two weeks ago for the birth of their first child. Noel and Carol are now stranded in Argentina, with airports not expected to open for another four days.
"The volcano started erupting on Saturday and the town was covered in about two inches of ash within hours, everywhere looked like a beach," Noel told the Herald.
"We can't really see the volcano here, but we felt an earthquake, and the thunder and lightening were phenomenal over the weekend, we've never seen anything like it.
"At first there was no running water, then we had thunderstorms and with the wind some trees must have fallen over power lines because we had no power for a few hours yesterday," John explained.
"Where normally it would be bright during the day from 9am, the whole day is like a very dark grey morning because of the ash.
"It's not too difficult to breathe, people are going around with masks over their faces, but my son and his wife cannot take the baby outside at all.
"Fionn was only born two weeks ago and they were due to take him to the hospital but he's too fragile to go outside in these conditions, we also haven't been able to contact the hospital with the power cuts but it could be worse.
"The airport is closed at least until June 12 and the only way to leave the country really would be to drive to Buenos Aires which is 20 hours away," the Drimnagh native added.
The volcano range, which is approximately 575 miles south of the Chilean capital Santiago, last erupted in 1960, shortly after a 9.5-magnitude earthquake hit Chile.
This latest explosion and the hundreds of tremors that it provoked have led to the evacuation of thousands of nearby inhabitants, and the closure of the border between Chile and Argentina.