By Lynne Hendricks
---- — NEWBURYPORT — They ski on it, shovel it and play in it when Mother Nature dumps a blanket of it on their front lawns. But what do kids really know about snow?
Quite a lot, actually, if they are seventh-graders at the Rupert A. Nock Middle School who took part in a place-based learning exercise this week.
The lesson saw the students transforming the snow-capped soccer fields behind the school into a community of snow shelters, or quinzhees, as the Native Americans called them.
The students learned that being aware of the unique properties of snow and water has, for centuries, meant the difference between life and death for humans stranded in the backcountry amid freezing conditions.
And on a more personal level, they learned why past efforts to build tunnels or snow forts in their own backyards might have failed. It turns out it all comes down to science.
“When you’re shoveling, you break up the crystal lattice,” said seventh-grader Brendan Tribastone, who was working yesterday to carve out the interior of his quinzhee with help from Liam Bixby and Kenny Hodge. “You have to let it reform.”
A quinzhee is a temporary, less-sturdy version of an Igloo, but is built on the same principles of snow as insulation that Inuit tribes have employed to shelter them from the elements since as early as 1576.
The design starts with creating a 6- to 8-foot pile of snow, then letting it `sinter,’ or strengthen, for three hours — one to two hours if you’re in an emergency situation and need to escape the cold.
As 7 Crimson teacher John Reynolds described the sintering process, when water begins to freeze, it makes a crystalline structure known as a crystal lattice, but those crystals are down during the process of shoveling or piling up the snow. By letting it sit for a while, or sinter, those crystals reform, allowing for safe construction of the interior of the quinzhee.
“We had to wait to make an entrance,” student Nicholas Fenner said. “Overnight, the crystals went back together.”
Using sticks inserted into the top of the quinzhees to a depth of about a foot, students began the digging phase of their project yesterday afternoon. They were advised to dig evenly as they went along as opposed to building a tunnel into the structure that could cause instability. When they came across a tip of an inserted stick, they moved their digging to another area of the interior so as to create an even ceiling depth all around.
On the third day of work scheduled for today, they will learn the most important thing about emergency snow forts — to dig the entrance about a foot lower than the cave floor so cold air will be pushed out and warm air will be allowed to rise and keep inhabitants toasty warm inside.
While igloos have been known to maintain a temperature of up to 61 degrees, Reynolds said a quinzhee can get as warm as 34 degrees when body heat begins to circulate.
“I thought it was going to be freezing,” a surprised Jess Puleo said after going inside.
“To me, it was warmer than on the outside,” Madeleine Clemente said.
“It’s a 10-degree difference (than the outside) at least — perhaps even more,” Reynolds told his students. “That’s something we’re going to monitor (today) with thermometers.”
Reynolds said the ability to create a warm space out of a cold substance is based on the unique heat capacity of water that allows it to become an insulator. While the process can be explained in the classroom, he said there’s something about going out into the back fields and seeing the process at work that cements the knowledge with students forever.
That’s the beauty of the place-based model, which takes advantage of the place where you live to teach lessons, Reynolds said.
“The timing was perfect because we had been learning about properties of water as part of a unit on the major chemical compounds in living things, like carbohydrates, proteins, nucleic acids,” he said. “Water is essential to human life. Many of the same things it does in nature, it does in your cells. The body is 65 percent water, which allows us to keep a somewhat constant body temperature.”
Science aside, some students are thinking of putting what they’ve learned to use immediately. Hodge and Bixby said they tried and failed to build a fort at home this past weekend following the blizzard, but it didn’t work out. They’re thinking a redo is in their future.
“I’m going to educate my family,” Hodge said.