Download
1 / 17
170 likes | 329 Views
By Edward Osborn GEOG 1700. Alaskan Permafrost. What is permafrost?. Permafrost is the term used for ground that is frozen solid year-round. When people refer to permafrost, though, they are almost always referring to permafrost thawing.
E N D
By Edward Osborn GEOG 1700 Alaskan Permafrost
What is permafrost? • Permafrost is the term used for ground that is frozen solid year-round. When people refer to permafrost, though, they are almost always referring to permafrost thawing. • This occurs when the upper layer of permafrost thaws during the summer and freezes again during the winter. This layer of earth is referred to as the active layer.
Permafrost problems • Permafrost is very problematic for humans. • When water freezes, it expands. When it thaws, it shrinks again. Water in the ground does the same thing. • This constant thawing and freezing of the ground has a drastic effect on the world above it.
Permafrost Problems cont. • Permafrost thawing often causes the earth, and the roads above it, to shift. This results in potholes, deep cracks, uneven road surfaces, and even dangerous dips and rises in roads. • Things like building foundations or tree roots that go down into the active layer can be seriously damaged by the expansion and shrinking of the earth around them. • Increasing permafrost thawing damages ecosystems and the communities that rely on them, specifically those in the native Alaskan community, many of whom live on a subsistence lifestyle.
Home, sweet home • My hometown, Fairbanks, Alaska, has huge problems with permafrost. There is a saying there that there are only two seasons in Alaska: winter and construction. I lived about 10 miles out of Fairbanks and commuted between the two once or twice a day. During the spring and summer there would inevitably be at least one crew working to repair permafrost damage to the road to the city. They would fix everything up by the time fall came and then begin fixing the new damage as soon as the snow melted.
This is a home in Fairbanks. Home damage from shifted foundations is not uncommon, though usually not to this extent.
It’s all uphill from here(and it only gets bumpier) • Over the last 50 years, temperatures in Alaska have increased by an average of 3.4 degrees Fahrenheit. • Warmer temperatures mean more ground being thawed every year, allowing the ground to shift even more. • The damage from permafrost will continue to grow for the foreseeable future.
What’s a man to do? • There is little that can be done at this point to prevent permafrost thawing, and decreasing average temperatures for the sake of construction or the environment would be a hard sell to most Alaskans. • Unlike living in a hurricane or tornado zone, the effects of living with permafrost are much more manageable. The downsides are more frustrating and expensive than life-threatening.
What’s a man to do cont. • There are certain building techniques that can be utilized to make your structure hold up better against permafrost thawing. • As you can see by map in slide 8, there are also areas of Alaska that are affected much less by permafrost thawing. • Overall, a rational cost/benefit analysis is what’s necessary when dealing with the frustrations of permafrost thawing.
Conclusion • Permafrost thawing, while not an immediate danger to human life, causes a lot of problems in areas with colder climates. • The damages, both financial and ecological, will only continue to grow as the earth warms and seasonal temperatures become more and more extreme. • While there is no easy or permanent solution, there are many ways to mitigate permafrost thawing’s effect on individuals and communities.
