Mary Shields

Martin and Dana (my advisor and his wife, pictured below with their daughter Sonja) won a bid at the Northern Alaska Environmental Center auction that was, well, a weekend at a remote cabin. They invited Inari and me to join them. All we had to do was ski 12 miles to this cabin located near Fairbanks, and everything else was provided. All of the supplies we needed were taken by dog team.


The owner of the cabin was Mary Shields, a long-time Fairbanks resident and dog musher extraordinaire. And an exceptionally generous person. For example, after being at the cabin for all of five minutes and having just met Mary, I remarked that I'd love to have a place like this to spend my weekends. She immediately responded by saying that I'm welcome anytime, and that the key is always hanging near the door.


She is quite the musher, too. She's raced in the Iditarod and Yukon Quest dog sled races many times - in fact she was the first woman to complete the Iditarod, although I didn't find that out until I got back into Fairbanks. Nowadays she works every day in the summer doing dog sled demonstrations for tourists. In winter she mushes, and each winter culminates with a month long trip somewhere in Alaska. She epitomizes Alaska (especially interior Alaska) as much as anybody I've met, and is a great example of why Fairbanks can be a great place to live.

Fairbanks Rescue Mission: a moral dilemma?

I mentioned in a previous blog that I would like to volunteer at a homeless shelter in Fairbanks. The only shelter here seems to be the Fairbanks Rescue Mission, a Christian-based organization that provides food, shelter, and clothing for Fairbanks' needy, transient, and homeless people. I don't object to religious organizations helping those in need - in fact I think its one of the most beautiful aspects of all (?) religions. What I don't agree with is when people try to impose their belief system onto others. What feels best for one person may not be the best thing for somebody else. I think all belief systems are fine, so long as they don't justify hurting somebody else or their property. Anyway, the Fairbanks Rescue Mission requires their "tenants" to attend chapel services and study the bible. I'm not sure that I want to support that... It's one thing to say that the food and shelter being provided to you comes from the grace of God - and even offer chapel services -, its another to try to forcefully convert you by taking advantage of your situation.

I'll keep searching though. Maybe there is another organization that I'm more willing to support.

The poor glaciers

At present, more than 90% of the glaciers on Earth are retreating. Of course, glacier retreat is not as simple as it may seem.

First, a little refresher: glaciers form when snow accumulation rates exceed melting rates over many years. Eventually the snow metamorphoses into ice as a result of increasing pressure in the snowpack. When the ice becomes thick enough, it deforms under its own weight and flows downhill. As the glacier reaches lower elevations, melting begins to exceed accumulation, until it reaches a point (the terminus) where the ice melts faster than it can flow forward. A change in terminus position can be due to a change in (1) air temperature, (2) snowfall, or (3) ice dynamics. Snowfall is related to air temperature, and ice dynamics is related to air temperature, snowfall, ice temperature, crystal size, and basal properties. It's clearly a difficult problem.

Furthermore, two glaciers located close to each other can behave very differently as a result of local variations in climate or dynamical processes. So the fact that over 90% of the glaciers are retreating is actually very alarming - most of the world's advancing glaciers are tidewater glaciers, which are glaciers that end in the sea and can behave independently of climate. I'd rather not get into the reasons for this, but I can point to the right direction if you're curious enough to learn more.

Evidence for glacier retreat is clear everywhere in Alaska; when walking in the mountains you can see recently-deposited moraines (rock piles left by the glaciers) that are now high above the ice surface. There is also plenty of photographic evidence - for example, see this photo at the USGS website.

A significant portion of this retreat can be attributed to natural cycles. Much of the Earth experienced a cooling period from about 1550-1850, dubbed the "Little Ice Age". And so some of this retreat is result of subsequent warming. What might not be attributed to natural causes is the increasing rate of retreat. Between the mid-1950s and mid-1990s, Alaska glaciers contributed about 0.14 mm/yr to sea level rise. Over the last 15 years, that rate has increased to closer to 0.30 mm/yr.

Glaciers in Greenland remained in pretty steady positions until the last 5 years or so. Now, all (?) glaciers south of about 68° N are rapidly retreating and accelerating. For example, Jakobshavns Isbræ, the glacier I will study for my Ph.D., has retreated 15 km in the last few years and ice flow has accelerated from 7 km/yr to ~15 km/yr at the terminus. Here's another common misconception, almost always screwed up the media and the anti-climate warming people - an accelerating glacier does not have to be advancing. The beds of the glaciers in Greenland are well below sea level. When the ice thins, it can become buoyant - this reduces the drag and also results in the rapid calving of large icebergs. (Yes, these are tidewater glaciers that can respond independently of climate, but that fact that so many of them are retreating simultaneously points to a climate-induced retreat. The popular theory at the moment is that the retreat is due to increasing ocean temperatures.)

Opponents of human-induced global warming would ask why didn't these changes happen earlier - we've been using fossil fuels for over 50 years. The answer to that is again related to the complex relationship between ice volume distribution and dynamics. Simply put, large ice masses respond slowly to changes in climate.

Heat wave

Now that it's finally warmed up (by 70 degrees!) I've finally had the chance to enjoy the ski trails around our cabin. That's one of the best parts about life in Fairbanks: I can literally put my skis on in the driveway and start skiing into a relatively pristine forest. And, from those trails, I can connect to a whole network of dog mushing trails and frozen rivers that would take me to Nome, Barrow, and beyond. Of course I haven't done that, but I could, and it's a nice thought to know that such opportunities still exist in the world.

As Fairbanks comes out of its coldest January in 35 years, maybe its an appropriate time to talk about human-induced global warming. A friend of mine (Joe) was curious to hear what I might have to say about the subject, since I am a scientist-in-training in a related field. I could quite easily ramble on about global warming, but he was hoping for an objective response, which means I should spend some time thinking about what I say. Plus I should warn that, although my research is related to climate change, I don't spend a lot of time thinking about how humans influence climate. I do hear about these things at conferences and seminars -- I just need to review my facts.

I think I'll start by reviewing evidence for global warming and the uncertainities with those observations, and then I'll get into the more controversial stuff (depending on who you talk to). If you have certain topics to be addressed, questions, or problems with what I've said, then post away!

To be continued...