James Hrynyshyn
Northern News Services

NNSL (Jun 19/98) - Permafrost researchers have been attracting more attention than they are used to in recent months thanks to worries about the effects of global warming.

But climate change isn't the only threat to communities built on arctic terrain. Bad planning and lack of basic geological information have already wreaked havoc with Yellowknife's buildings and roads.

Stephen Wolfe of the Geological Survey of Canada in Ottawa spent two years in Yellowknife studying what's happening to the frozen ground that lies beneath the city's streets.

Tuesday night he'll be presenting some of what he has learned in a free lecture at NACC, beginning at 8 p.m.

He may also have some warnings for the city's public works and engineering staff.

For example, said Wolfe in an interview Thursday, "part of Niven Lake will be a problem when they develop it."

Developers of much of the Niven Lake subdivision will face the same challenges that have plagued city crews on the northern reaches of Franklin Avenue and most of School Draw.

Beneath each region lies silt and clay deposited 10,000 years ago when the entire area was flooded by a glacial lake. Such geology harbors "ice lenses" of permafrost that can melt once the surface is disturbed, devegetated or paved.

According to Wolfe, city planners "recognized that School Draw would be a problem area."

In fact, advertisements for School Draw lots in 1968 included a warning: "Soil conditions throughout the subdivision are not, in all cases, suitable to the use of conventional foundation systems. The purchaser must bear this in mind when investigating and selecting his lot."

Franklin Avenue, meanwhile, suffers from similar oversights, but compounded by heat-absorbing asphalt. "As soon as you pave a road, you have a problem. You're asking for trouble."

Wolfe's Tuesday night lecture also promises to cover technologies and techniques used to deal with the challenge of building on permafrost.