Wednesday, July 06, 2011

I Learn All About Frost Heaves

What do frost heaves do? They make humans take eight hours to make a five hour trip!

Our trip today started at the southern end of the blue line at Destruction Bay, Yukon Territory -- a teeming metropolis of 55 people, one of whom "worked" as a waitress in the town's only restaurant and thought an hour and ten minute wait for dinner was no big deal. But I digress. After leaving Destruction Bay, we made our way up to the Yukon Territory/Alaska border, and then to Tok, Alaska.

Notice the section from Destruction Bay to the Border marked "Bad Road?" This is where frost heaves almost literally raised their ugly little heads and made the trip a headache for everyone on the road.

Frost heaves are displacements in the pavement that are caused when a road is built on top of permafrost, and the heat from the road melts the ice below. Melted permafrost causes the soil under the road to liquify, essentially turning to mud. Because the winter climate here is quite cold (more on that later), it refreezes quickly -- and as it does it expands and heaves. What you end up with is waves in the road, bumps in the road, dips in the road, and potholes galore. And, for some reason we couldn't fathom, some stretches are "fixed" for several yards, then there is a rough patch, then another "fixed" patch and so on, so it looks like one row on a giant checkerboard except, of course, it goes on seemingly forever.

We drove on these bumpy, rolling, patchy, dusty, gravelly, rearrange-your-cabinet roads for over 135 miles.

The reason this road is in such poor shape is a problem that is simple to state -- the frost heaves keep happening because no one really knows how to keep the permafrost under the highway from melting (buildings in the arctic solve the problem by raising the foundation on stilts -- not a reasonable solution for an entire highway). We saw several road crews dumping sand and gravel on the road and tamping it down, but there was no evidence of a more permanent fix.

A permafrost research project is underway, which results in strange doohickies cropping up along the highway that are designed to -- hopefully -- keep the permafrost frozen by allowing cold air to penetrate under the road:

Finding cold air is not a problem. The Indian village of Snag (see map) has the dubious distinction of recording the all-time low temperature in Canada at -81.4 degrees F on February 3, 1947. Even the "regular" winter temperatures are daunting -- Tok's mean average temperature in January is -19 degrees F, and their average low is -32 degrees F. I just don't have enough long undies to survive a winter here!

Tired and road-weary, we finally got to the Alaskan border. Just before the border crossing, we discovered that the border between Canada and United States is marked by a swath of cleared land:

Even though they were purchased in the United States (Skagway), we lost a lemon and two limes at the border. The customs agent told us we could keep the fruit if we removed and discarded the peel -- apparently there is a fungus on the peel of some citrus fruit and they are trying to keep it out of Alaska. We decided to just leave the fruit, a decision we later regretted when we found out a single lime in Tok (rhymes with broke) is $2!

3 comments:

Sharon Del Rosario said...

My bad - I should have told you how expensive lemons are here. But we found them at Chubby's for $.89 - a bargain - I bought 2!

We decided to go to Dawson City instead of taking the road you did to Tok. We had a delightful time, and got to drive the Top of the World Highway. Gravel, frost heaves, narrow places, but a wonderful experience!

Enjoy Tok. They have some of the best 'tourist' prices in the state.

Judy and Luke Rinehimer said...

Know those scenes well. What did you think of the surprise road condition when you hit the US border crossing. Frank said it was a trick -- and it was. I do have to say that the US repairs were much better than the Canadians. We lost some fruit crossing the border but I was allowed to cut my lonely tomato so it could stay with us.

Nancy said...

Just think if you had paid more attention in school when they taught us about tundra, you would have expected the road conditions you experienced! And not been surprised! Bonus to the cold weather--- get to cuddle more with your honey!