Tuesday, January 24, 2012

Storms -> Rock falls

I know I promised acoustic ice blogging, but that will come in a minute. FINALLY, FINALLY it snowed. A lot. Many inches of rain down here, snow at 4000', and the Tioga Road closed due to snow on January 18th (although, it didn't snow until the 20th). And precipitation brings rock falls. We responded to one small event on the Hetch Hetchy road on Friday afternoon, but the really big event happened on Sunday night. A boulder the size of a house slid off the top of a cliff, bulldozed dozens of trees over, and removed a large chunk of the Big Oak Flat road. This road is the main route into Yosemite Valley from the SF Bay area - I've driven past here 100 times. Here's a shot of the boulder (at the bottom).



They called Greg, and Greg called me, so we went to have a look. We start from across the canyon and found that the best view was from a Wawona Tunnel portal, to see the source area (on top). There were clear bulldozed trees on the top and the bottom of the cliff, but it looks like the boulder cleared the large cliff entirely. Then we went over to the rock fall and had a look at the debris. Mostly we are assessing where the rock fall came from and whether more rocks are likely to come down in the near future. An inexact science... but we use our best educated judgement. In general, we don't want workers sent in there if there is a large instability, which does not look to be the case for this rock fall. Here's the road:





The workers started clearing the road today and may have a single lane running soon, although fixing the road will likely take months. There are many people who rely on that road and will be happy when it is fixed. In fact, one of our coworkers is bunking at our apartment since she lives on the other side of the road, and cannot get home easily. Here's a shot of some roadwork:

Saturday, January 21, 2012

Amazing Alpine Ice: Tenaya Lake!

The winter of 2011-2012 is one of the driest on record out here in California. A few snowflakes fell in October and perhaps even a bit in November, but through mid-January, it hasn't snowed! The Tioga Road, through Yosemite's Tuolumne Meadows (8600') and over Tioga Pass (9943') was still open on President's Day weekend, when normally it closes in November!!! These unusual conditions opened up a variety of rare opportunities to visit alpine areas in the middle of winter, and in particular, to enjoy the glassy ice that formed to many inches of thickness on alpine lakes and rivers. As many of you know, the lake ice emitted many low frequency whale-like booms, mid-frequency cable twangs (or, laser guns), and high frequency cracking noises each day: those will be the subject of the next blog post. THIS blog post is about the ice and silliness that ensued!!!

The main attraction was Tenaya Lake - here's a gigapan by Kurt!


Well, it wasn't *technically* illegal!


So I went skating!


The ice bubbles were awesome (photo by Kurt)




and by Phil:


And people were having a GREAT time!!!
There were bowling balls:


And dogs towing people:


And chair sailing (I sailed all the way across the lake!)


And hockey games, pogo sticks, large kites, bbqs and tables and chairs, skateboards...

And awesome sunsets and moonrises too:
Photo by Kurt:


Photo by Kelly: