Is the lake ice safe? Ask UB's 'ice man'

By ELLEN GOLDBAUM
News Services Editor

At UB, the "ice man" cometh with an ice auger, an ice spud, a meter stick and a couple of screwdrivers that hang from a string around his neck.

Kenton Stewart, professor of biological sciences, is UB's ice man; in fact, he may have the largest scientific inventory of lake-ice dates in North America, covering more than 250 lakes in New York State alone and several hundred in other states.

Stewart teaches limnology, the science of bodies of fresh water. One of his research projects involves studying the freeze and thaw dates of lake ice as an indicator of global climate change.

That work has led him to develop some skills in determining whether or not a lake's ice cover is safe to walk on; at UB, he has performed this sometimes risky service almost every winter for the past 20 years.

On a recent expedition to test the ice on Lake LaSalle, he strode quickly out onto the middle of the lake. His guests stepped carefully behind him as swiftly as they dared.

"I'm not worried about the ice on this part of the lake," he said, noting that just a few days before, he had measured 10 inches of cover on the lake.

Still, he decided to demonstrate just a few feet from shore how, when he's less sure of the conditions, he makes certain he's not putting himself in danger.

He held the ice spud, a long rod with a sharp tip, in both hands and slammed it down into the ice.

"This is the one-two-three test," he said.

If the spud's tip goes completely through the ice on the first slam, he explained, it's time to get off the ice because it's definitely not safe. If it takes two slams in the same spot to break through the ice, Stewart said you have "a little margin of safety, but not much." If you slam it hard three times in the same spot and you can't break through, you're probably fine proceeding a little farther out. However, Stewart cautioned, since ice thickness varies in different locations, it must be rechecked frequently.

Thirty paces out, Stewart decided to take his first measurement. He brushed the snow away from the lake's surface, then plunked down the ice auger and began drilling a hole into the frozen floor. He turned the handle, going deeper and deeper, then pulled it free. Just inches from his and his guests' feet, a small spring of water gurgled to the surface.

Stewart stuck his meterstick down into the water: 29.5 centimeters of ice, or about 12 inches.

"This is twice as thick as the maximum amount of ice we had all last year," said Stewart, adding that last year the lake was thick enough to walk on for only one week and there were 54 days of ice cover, the fewest number since 1975.

He pointed out that last year also was a strong El Nino year, a phenomenon that reflects differences in sea-surface pressure between the eastern and western Pacific Ocean. When those differences are especially pronounced, that spells an unusually mild winter for parts of North America.

This winter, on the other hand, is La Nina, the winter following El Nino that usually is characterized by colder weather with more precipitation, which Buffalonians came to know all too well earlier this year.

"El Nino events vary in their impact and do not affect all parts of the globe equally," he said. "The biggest unknown is what the effect is regionally."

To examine how different regions are impacted by El Nino, Stewart monitors more than 250 lakes throughout New York State and hundreds of others in other states.

"I do these long-term studies to see whether lake-ice dates can serve as proxy indicators for climate change," he said.

Strictly a grass-roots effort, the project began around 1970 when Stewart was looking at a few of the Finger Lakes. From there it escalated.

Stewart obtains data from a vast network he developed of ordinary citizens who live near lakes he monitors. To find observers, he uses any method that works, asking for referrals from local sporting-goods shops, post offices or from a local game warden.

Through phone calls or postcards, the observers let him know when their lakes freeze over in winter and break up in the spring.

According to Stewart, over the years, some of the lakes have begun to show one sign of global climate change: an earlier break-up of ice in the spring. He presented some of his research results last summer at a meeting of the International Limnology Society in Dublin.

Asked why he organized the network of observers, he said that the project provides him with a lot of climate information that he couldn't get any other way. He also enjoys making his own lake-ice measurements, working in the beauty of nature, which is also sometimes a challenge.

For example, when conditions on Lake LaSalle aren't good, he makes sure to take along a life jacket and a toboggan, which he can pull up to the edge of the ice. That's also why he always takes screw drivers with him, so he can "claw out" if he falls in. Luckily, he hasn't had an accident since he was a graduate student.

"It's strenuous work and can be a little nerve-wracking at times," he conceded. "But it's the most direct way to get this information. That's part of the lure of science."