Is it ski season yet?

I was tempted to go skiing today but I woke up too late and I'm not convinced there is enough snow yet, unless I rent some sacrificial skis.  So, in preparation for an evening of too much turkey and the associated goodies, it was time for Poo Poo Point, in Issaquah. Snow from earlier in the week lingered in the parking lot and on the trail.  The footing was more than a little treacherous, especially on the rocky steps in the lower section.  A passing hiker stopped to alert me to the high south winds in the meadow just short of the summit.  Although I didn't probe him at the time he left we wondering what I should be so worried about.  Was it the wind chill?  Perhaps there was danger that trees would start toppling over. In any case I decided to take my chances, knowing full well I could turn back at any time.


I reached the summit after an hour or so and enjoyed watching clouds blowing by at a fast clip.  Sqauk Mountain was covered in snow and capped in clouds.

I scrambled up about 50 feet higher to inspect the wind socks and other equipment.

The sign forbidding launches with horses present seemed a bit ironic as there was neither a glider nor a horse within miles.  It wasn't as windy as I expected because the trees were blocking the south wind.  I noticed a couple of unusual pieces of equipment. 

The EarthScope project is funded by the National Science Foundation to study plate tectonics, earthquakes, and other geological issues.  It's not exactly clear what equipment is installed on West Tiger Mountain, but it seems to be a highly precise GPS device that measures the location of the sensor over the years and decades.  Geophysicists can look at the movement of these units relatives to one another and make inferences about the movement of plates.

The cross-section below shows the Pacific Plate subducting under the North American Plate, which has given rise (pun intended) to the volcanic peaks in the Cascade Range, including Mount Rainier.  This type of plate boundary is responsible for major earthquakes around the world and if magnitude 8 or 9 tremor hit the Puget Sound region there would be massive damage and loss of life.  But enough happy thoughts for now.

 

Source:  http://www.earthscope.org/science/convergent_margins