Monday, November 1, 2010

Geology Field Work and Weather Monitoring

We are entering the time of year where it is highly advisable to keep close tabs on the weather when planning field work. Besides avoiding hazardous weather part of my work is assessing geology hazards and big storms and geology hazards are very much linked. So I routinely check and Western Climate as well as cliffmass.blogspot .  I do as much if not more field work in the winter as I do in the summer. The mild western Washington winters generally do not preclude field work, but it is a good idea to keep an eye on the weather reports while planning ventures on steep slopes or in the forest.

From a safety perspective several weather issues come up in doing my geology hazard work. A primary issue is wind. It really is not a good idea to be in the forest during a wind storm. I lived in Kennewick, Washington while in high school where winds of 80 mph are not uncommon. A little 40 mph breeze was not a reason to not go for a run - not particularly pleasant while running into the wind but great mile splits when it was at your back. But Kennewick is not forested. When I moved to Seattle I would go running in Ravena Park or along the winding paths at the north end of Capital Hill. Running through Ravena Park during a wind storm was a lesson that I have not forgotten. Besides limbs falling the ground was moving as the trees were being tilted and the roots were pulled upward.

Another issue is snow. I love snow but it presents two problems. Access to sites with steep roads gets harder and a covering of snow makes it difficult to figure out the geomorphology.

Deep freezes can pose a challenge to digging hand dug test pits. Frozen saturated soil can be very difficult to dig through after a week of sub 20 degree temperatures.

As for rain that is part of the routine of living and working in western Washington, but I do try to time the Pacific fronts - sometimes to stay dry but there are times when I want to actually be out when a big rain storm hits. The fact is much of our landscape is shaped not by typical storms but by the big storms. Two winters ago I was working on a project in the coast range of Oregon where high water levels in the river canyon and its tributaries had caused approximately 70 millions dollars of damage. The river did not have a gage station. I managed to time a storm hitting the area perfectly and hiked up the canyon during a period when 5 inches of rain fell in 8 hours. It was like working in a bathroom shower. I came away with a much better understanding of the river and a lot more confident in my interpretations.

So this time of year I begin looking at the National Weather Service web site a lot more frequently and pull up long term weather models at the UNISY site. Cliff Mass is always good for proving an earlier warning if something big might be developing. And I try to be flexible with my field schedule and let clients know that field plans are subject to change. Northwest Washington is subject to occasional very cold winds with Arctic air flowing out of the Frasser valley just north of the border. For drilling projects, I know that drillers appreciate a warning if a hard cold northeast outflow wind is expected. Even if they don't bring warm enough clothes, they can't say I did not warn them.

I posted this picture of an approaching weather front before.
This storm caught me off guard. 
I had not been tracking the weather while traveling.

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