By VINCE MEYER
Outdoors Editor

The hole in the ice on North Long Lake stays open because the water is warmer in that part of the lake, researchers announced Tuesday.

Why is the water warmer in Highway 371 bay than in the rest of the lake?

"Good question," said Al Cibuzar, head of the research team studying the hole. "At this point we don't have any answers but we've eliminated a few things and that's important."

A theory that's been eliminated is rapid water movement. Researchers placed dye in the water and observed it with a time-lapse videotape. Had the dye moved the motion would have been revealed on the tape. Cibuzar said some movement was observed, but not at the rate necessary to keep the hole open.

"The amount we saw might have been caused by the diver going down," Cibuzar said.

Water temperature in the hole ranges from 37.7 degrees to 41.5 degrees, Cibuzar said. Typically, water near the surface of a frozen lake is about 34 degrees.

The research team, which includes scientists from A.W. Research Laboratories and divers from the Minnesota School of Diving, wanted to study the hole at 12 locations. But on Jan. 8, the day the hole was studied, it had frozen over and just four locations were studied. Chemical and physical tests were made on the surface and on the bottom in transects extending east and west in the hole.

Cibuzar said additional tests will be made "as soon as I can stop doing news interviews and do the science."

Tuesday, reporters from ABC World News Tonight and the Wall Street Journal were here to do stories about the hole.

Officials remind the public that ice conditions around the hole remain hazardous.