Early Snow in the Sierra Nevada! During a field trip, of course.

Snow-capped peaks above Hope Valley

What a difference a week can make! Seven days ago I was in the Owens Valley and eastern Sierra Nevada, and though we got a bit of inclement weather, it was a warm storm, and we were barely inconvenienced. The pictures (here and here) show little in the way of new snow or ice. But then there was this last weekend. I was leading a short tour of Lake Tahoe for conferees at the SciX conference in Reno, Nevada, and from the moment we arrived at the lake on Friday to this afternoon, it was raining and snowing.

Fall colors and snow at Carson Pass

Lake Tahoe may have received on the order of two inches of rain, and a fair mantle of snow could be seen on the peaks above 8,000-9,000 feet. The white snow combined with the just-beginning fall colors was a beautiful sight. It kind of wreaked havoc with our field trip though. The rain was constant and the temperature never rose above 43 degrees or so. It was snowing on us at Mt. Rose Summit. Our only comfortable discussion took place inside the visitor center at Sand Harbor near Incline Village.

Lake Tahoe near Cave Rock on Saturday

Just the same, I wouldn't have changed a thing. California is in the midst of a horrific drought of epic proportions. The situation is growing desperate in California and other parts of the American Southwest and it will take several years of normal and above-normal precipitation to make up the steep deficit. An early snowfall is a good sign and hopeful beginning to the new water year.

On Highway 88 below Cook's Station

As we were coming home this evening we were treated to a wonderful sky show as the storm began breaking up. At times the cumulus clouds looked like volcanic eruptions or nuclear bombs in the distance.

Oaks and cumulus clouds near Mokelumne Hill and Valley Springs

The storm had petered out by the time we reached our prairie-lands around Milton and Oakdale. We were treated to a colorful sunset.

My First Day of "Summer"...

Well, this is what a "compressed academic schedule" looks like...my first day of summer employment hiatus. A few years back the school wanted to run three full semesters a year, so shortened our fall and spring semesters to 15 weeks, adding a few minutes to every class and laboratory section. Some people like it, but it has had an unfortunate impact in the sciences, as we went from 17 labs to only 15. You can't spread the content of the two missing labs very well among the others. Unfortunately the summer semester was decimated by the California budget crisis, so I am presently idle, as my summer classes were canceled.

Well, I don't want to vegetate, so I am off to the eastern side of the Sierra Nevada for a conference of the National Association of Geoscience Teachers. To get there, we had to drive over Carson Pass on Highway 88 through Kirkwood Ski Resort, to Genoa, Nevada, then to Lee Vining and Bishop, a little over 300 miles. It's April 30, and it was snowing in the mountains yesterday! Luckily, the roads were dry and clear today.

The snow pack is obviously still pretty thick, so the geology is a bit obscure, but along the way to Carson Pass we passed Caples Reservoir, where we could see the high peaks composed of andesite lahar deposits from around 10-20 million years ago. They have been extensively modified by the Pleistocene glaciers, and make a beautiful backdrop to the lake.

We made our way south to Conway Summit, where we had a startling view of Mono Lake and Mono Craters. Mono Lake is the very salty remnant of an ice age lake that was hundreds of feet deeper, and once spilled over into the Owens Valley. The only way the water leaves to day is by evaporation. The story of the near destruction of the lake ecosystem because of the diversion of water by Los Angeles could fill many blog posts (and probably will before too long).

The Mono Craters are actually rhyolite plug domes that have erupted between about 35,000 years to only 600 years ago (the youngest, Panum Crater, is the small one in the foreground). They may be part of an evolving caldera, but mass destruction is probably hundreds of thousands years away.

In the late afternoon, we crossed through the Long Valley Caldera, which did cause massive destruction across the entire region 760,000 years ago. An eruption explosively tossed 130 cubic miles of ash across most of the western United States, and the ground over the magma chamber collapsed to form a hole that is 10 miles by 18 miles, and once may have been two miles deep. The high peaks of the Sierra Crest that form the western and southern edge of the caldera are composed of Paleozoic and Mesozoic metasedimentary and metavolcanic rocks that have been intruded by Cretaceous granitic rocks.

Tomorrow we will be geotouring through region, and more pictures will undoubtedly follow! Mrs. Geotripper took the top and bottom photos, I took the others.