Thursday, March 10, 2011

Evidence of the Anthropocene in Washington

The term Anthropocene was first suggested by Paul Crutzen, a Nobel prize winning atmospheric chemist. The term has not yet officially been adopted by the International Geologic Congress, but the term is being used more and more frequently and is becoming generally accepted. One question that will need to be resolved is when the Anthropocene epoch began. That is at what point did humans start to impact the planet so much that it warrants the delineation of a new epoch. And depending on the date determined, what will become of the current official epoch, the Holocene. Tricky stuff and likely great fun to argue about. Zalasiewicz and lots of others (2008) lay out many of the issues in a fun paper that also is a bit disturbing when you consider the impacts humans are having on the planet relative to geologic and atmospheric processes.

I will say that in my work as an engineering geologist trying to read the landscapes I see and figure out why the ground looks the way it does, I routinely distinguish between pre Anthropocene and Anthropocene events. Of course there are many natural processes that dwarf anything humans do, but the idea that humans are having more and more of an impact on the landscape is abundantly evident.

Water ski lake southeast of Blaine, Washington

The above lake caught my eye today while looking at another site in part because not only can the boat be seen in the lake but the water skier behind the boat can be seen as well. This lake is an Anthropocene lake. It is erosional feature. The eroded material was then deposited in linear parallel lines that can be seen on the lower left of the image. Or put in another way: gravel was mined down to below the water table to provide aggregate for the construction of Interstate-5 in the early 1960s. By that time the Anthropocene was well underway in Whatcom County and Washington State. 

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