EXPLAIN
I found much of this module's information interesting and challenging. Beginning at the very first part and continuing all along the way, I had to stop many times to think about what I'd just read. The earliest instance was the explanation that terrestrial ice is made up of “frozen fresh water instead of saline sea water.” This made me go back and review our earlier module, and it connected with me that sea ice forms at the surface when the saline content decreases. Of course! I can see how that would be true! It's a small epiphany, but for me an important one, as is every new thought and new understanding, especially in regard to the uncharted waters--pun intended--of science.
http://www.waterencyclopedia.com/Re-St/Sea-Water-Freezing-of.html
The text also says that there is a “different set of variables” that impacts time scale, and goes on to list those variables, most of which I could apply to the sea as well as to land. Again, it brought me back to the salinity of water.
According to the Water Encyclopedia:
"Salty water freezes below 0°C (32°F): this is why salt is used to melt the snow or ice on a road pavement. The saltier the brine , the lower its freezing point. This is also why salt traditionally was added to the water–ice mixture used to make ice cream."
Yes! Scattering rock salt on ice to melt it is an old practice. And I when I lived in California and my children were small, I had an ice-cream maker with a compartment surrounding the bowl, which I filled with a salt mixture before we started cranking the mechanism, just as the quotation above points out.
http://www.leehansen.com/coloring/Parties/index.htm
Our text says that “changes in temperature along with changes in latitude, altitude, precipitation and the different heat capacities of land and water all interact to create the dynamic realm of terrestrial ice; glaciers, permafrost, rivers and lakes.” In addition to raising the questions I mentioned above
(Do these variables not affect sea ice? What are the differences?), this section sparked quite an interest in inland lakes. In response, I found a very informative study titled "Advancing Landscape Change Research through the Incorporation of Iñupiaq Knowledge” that acknowledges the importance of indigenous knowledge and contains an emphasis on lakes. As they say, their research "demonstrates that indigenous knowledge can reveal a new understanding of landscape changes on the Arctic Coastal Plain in general and on lake processes in particular."
As for permafrost and its effects, I found lots of good information at this website – be sure to scroll down to the 2003 video clip of Ron Bower, Sr., where he "describes the very rapid sediment erosion taking place along the bluffs near his cabin on the Meade River Delta. Ron has had to move his cabin away from the bluff as the bluff face continues to erode." A good talk from a knowledgeable man that clearly illustrates the impact of climate change happening on a personal level.
http://www.fs.fed.us/r10/tongass/forest_facts/resources/geology/mendenhall.htm
I had thought that the Taku Glacier was pretty much the sole glacier still advancing, or rather, not retreating, but I learned that quite a few glaciers in Alaska are not retreating, including Lamplugh, Aialik, and Harvard Glaciers. The Juneau Icefield Research Program is busy collecting data about the Juneau Icefield, and provides good information and descriptions of their projects and the results of their research.
EXTEND
The Drop in the Bucket quiz challenging the reader to estimate distribution of Earth's water supply was fun, as was the quiz on 1000 Snow Flakes. I'm happy to say I did better than I expected at both quizzes. Both quizzes also reminded me of the Village of 100 and Village of 1000 exercises I once used in freshman seminar, and still try to work into other class activities now that I no longer teach that original class. Brain-teasers! Or rather, Brain-stretchers, I suppose.
http://xweb.geos.ed.ac.uk/~mhagdorn/glide/glide-doc/num/figs/basal_bc.png
Finally, I also made a connection to something I learned long ago when I was constantly studying and researching for my job as a summer shipboard interpreter on the Alaska State ferry: the relatively thin layer of water underneath glaciers that allows them to “flow,” termed basal sliding. At such high pressure, things apparently turn into their densest form, which in the case of water, is its liquid form, creating a thin sheet of water under the glacier upon which the ice slides. There's no doubt that this would make a great activity, as would the data on the Nenana Ice Classic, something I can remember everyone in my family guessing even when no one had an extra dollar to buy a ticket. Does every Alaskan family have a story about a favorite uncle who guessed the right time but didn't buy the ticket?
Well, I've already said my piece about "discovery," so I'll limit my critical remarks this week to one: In the Timeline of Human History, the section titled “Prehistoric to Present” seems quite brief, sending the plain message that it's "prehistory" (what is oral history if not recorded history?) and therefore not important. If people in authority are actually taking oral history seriously, it does seem as though a conscientious person would put a bit more thought and far more acknowledgment of the indigenous records of history into the design.
Beginning in 1741 with Chirikof, the descriptions are far less perfunctory, giving the unspoken but clear cultural message that we've come to the important part. What do we suppose children--Native and non-Native alike--are receiving from this treatment of history?
I've already expressed my evaluation of the good parts--all the rest!--of the module. I enjoy learning, and I know I will make good use of my new knowledge. Gunalcheesh!
BLOGS
Amy not only points out excellent information about permafrost, but she relates meaningfully it to the students in Gambell and provides an example of how Teacher’s Domain is an excellent resource for her students.
Tyler also related this week’s lesson to local concerns, specifically his involvement with building a hydroelectric project to serve Sitka.
Tracy’s blog had lots of good information and links. I know I will benefit from the information and added thoughts in others' blogs as well as in the lessons.
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