Sinkhole mystery continues in N.S.

Nova Scotia’s sinkhole remains largely mysterious, and officials are bringing in ground-penetrating radar and other technology in a bid to better understand what is happening — and how big it might grow.

The sinkhole’s growth has slowed considerably, but provincial geologist Amy Tizzard said “little mudslides” are occurring at the edges, and cracks are continuing to appear in nearby pavement in an Oxford park.

“You can’t say it’s contained or under control because it’s Mother Nature and she’ll do what she wants,” said Tizzard.

“We are monitoring it to see if we are seeing any patterns in the development and then use that information to predict what the risk would be in the rest of the area around here.”

A large spruce tree fell into the sinkhole overnight, according to town spokesperson Linda Cloney.

First reported July 28 as a small hole about the size of a dinner plate, it was measured Tuesday at 32.6 metres by 38.7 metres — larger than an NBA basketball court.

Tizzard said officials are measuring existing cracks on nearby land and looking for new ones, and using a drone to collect highresolution imagery of the site.

“So far we are using high-accuracy GPS equipment that will tell us if there’s any subtle variations either vertically and horizontally on the ground surface ... and we’re mapping out cracks in the pavement and in the forest around the sinkhole and monitoring how fast those cracks are growing, opening up,” Tizzard, regional geologist with the Department of Energy and Mines, said Monday.

“We’re looking to, and hopefully will start this week, employing some geophysical methods like ground penetrating radar and electrical resistivity tomography and any other geophysical technique that might be suitable for mapping out any fissures or fractures or caverns in the subsurface.”

Tizzard said radar and other technology is “en route” to the site on the outskirts of Oxford, a sleepy town of about 1,000 people that calls itself the wild blueberry capital of Canada.

The sinkhole has swallowed trees, picnic tables and part of a nearby parking lot at the Oxford and Area Lions Parkland.

Canadian Press photo A sinkhole is seen in Oxford, N.S. on Monday. A large sinkhole in the small Nova Scotia town appears to have stopped growing, at least for now, as officials continue to monitor the situation.