Wednesday, January 28, 2015

The Sierra Beyond Yosemite: A Stunning Impenetrable Wall of Solid Rock

Mount Whitney from the Alabama Hills in the Owens Valley
Impenetrable. The imaginary mountain barrier surrounding Mordor in the Lord of the Rings has nothing on this real-life wall of solid granite. For more than one hundred miles, from Mono Lake south to Owens Lake and beyond, there is a 10,000+ foot high crest that divides California from the rest of the country, which stops almost all precipitation from Pacific storms, and which denied immigrants an easy path to the gold-fields of the Mother Lode.
The Wheeler Crest from Bishop in the Owens Valley
The Sierra Nevada is a barrier to travel of all kinds: paths, wagon trails, roads, and railways cross the mountains in only a few places, and those few places present serious engineering challenges. No paved roads cross the mountains for well over 150 miles between Tioga Pass in Yosemite National Park, and Walker Pass south of Sequoia National Park (The only minor exceptions: Sherman Pass, a paved former logging road is inappropriate for heavy traffic, and a dead-end road that travels to Devils Postpile). The only freeways exist at Donner Summit and Tehachapi Pass.
The Sierra beyond Yosemite provides some of the most stunning scenery on the planet. On the previous day of our fall trip we had crossed the Sierra Nevada at Sonora Pass, and explored the ghost town of Bodie, but the sun was disappearing in the west by the time we arrived at our campsite in the little town of Bishop in the Owens Valley. For those on our trip who were seeing these lands for the first time, it was a revelation to wake up to the high remote ridges of granite and metamorphic rock that towered over the flat valley floor.
Mt. Humphreys (13,996 feet) above Bishop, California in the Owens Valley
Many would say that Death Valley is the ultimate expression of basin and range style geography, and in many ways it is extraordinary, but few valleys in the world can match Owens for pure grandeur. One one flank, the Sierra Nevada rise to elevations exceeding 14,000 feet. On the other, the White Mountains average 11,000 feet, culminating in White Mountain Peak at 14,252 feet. Given the roughly 4,000 foot elevation of the floor of Owens Valley, the declivity is twice as deep as the Grand Canyon. Comparisons are unfair, of course, since the Grand Canyon is water-carved, and the Owens is of fault origin, but the scale of the landscape is grand in any case.

The origin of the wonderful scenery is a two-edged sword, of course. The faults that formed the Owens Valley are still very active. In 1872, the Owens Valley fault was responsible for one of the biggest earthquakes in the state's recorded history. The magnitude 7.8 event killed 27 people (out of a total population of around 300), and shifted the ground dozens of feet along a scarp more than eighty miles long.
The Palisades Group of peaks on the Sierra Crest from Sierra View in the White Mountains

One of the most spectacular ways to see the mountain wall is to climb into the White Mountains and see most of the Sierra escarpment from one view point. It's called (by incredible coincidence) Sierra View, which is a pullout on the equally spectacular road to the Ancient Bristlecone Pine Forest. From the one view, one can see the Sierra Crest from the Tioga Pass area to south of Mt. Whitney, a distance of over 100 miles. We were blessed with a clear morning despite the fires raging throughout the region.

Later in the day we drove south to Lone Pine, which lies on the floor of the Owens Valley beneath Mt. Whitney, which at 14,505 feet is the highest point in the lower 48 states. After a number of stops, we ended up at an old mine, the Reward, and watched the sun sink over the high ridges.
Sunsets for the people of the Owens Valley are different. There is no horizon over which the sun emerges or sets. There are only high ridges. When the conditions are right, the light show is wonderful.

Monday, January 26, 2015

The Sierra Beyond Yosemite: Where the Sierra Ends (maybe), and Gold

In some places it is pretty clear where the Sierra Nevada ends. For a hundred miles or more there is a solid rock wall that reaches a height of two miles in the Owens Valley. There is no mistaking that the mountains end at the cliffs above Lone Pine. Likewise, it's an unmistakeable demarcation between the flat Great Valley and the Sierra Nevada foothills. But in the central and northern Sierra Nevada, the division between "Sierra" and "not Sierra" is a line not so easily drawn.

From Mono Lake to the north, there are fault lines that mark the edge of the Sierra Nevada structural block, but they diverge from the watershed crest of the range, forming a series of north-trending ranges and valleys. These ranges, the Bodie Hills, the Sweetwater Mountains, the Pine Nut Mountains, and the Carson Range, are connected directly to the Sierra Nevada, are composed of rocks related to the Sierra Nevada, but are often considered "not" the Sierra Nevada. Geologically, the Sierra Nevada block is moving northwest from the adjacent Basin and Range province, making it a so-called "microplate", a much smaller version of the North American or Pacific tectonic plates. The mountains mentioned above are the jagged edge of the incipient plate boundary that has not yet completely separated from the rest of North America. If you are patient enough, buy up some desert scrublands  in the Great Basin of Nevada. In a few million years they may be oceanfront property!

Our journeys last fall through the "Sierra Beyond Yosemite" took us over Sonora Pass and into the lands east of the Sierra Nevada crest, a land that is both "Sierra" and "not Sierra". Our first destination was the ghost town of Bodie, between Mono Lake and Bridgeport Valley in the Bodie Hills.

"Hills" in this instance is a deceiving term. In any other setting, the Bodie Hills would be considered mountains, reaching elevations of more than 9,000 feet, and rising steeply above the Mono Basin. Still, the hills around the ghost town are more gently rolling, having not been glaciated, or deeply eroded by rivers. They lie in the rain shadow of the main Sierra crest, receiving only 12 inches of precipitation a year, making the region technically a desert (in climate terms, a dry-summer subarctic environment). Bodie competes with Barrow, Alaska as the place in America with the most freezing days per year: 308 of them on average. I just can't help thinking that this was a miserable place to live. Why would anyone...oh yeah, gold.

As I've described before, Bodie was a gold mining town. In the decades following the fabled Gold Rush, hungry miners started to explore the region east of the Mother Lode, and over the crest of the Sierra, and a lucky few found the elusive metal. W. S. Bodey was one of these; his exploration party found gold in 1859 in what later came to be known as the Bodie Hills (apparently the spelling was changed to help with the pronunciation). He may have found the gold, but he wasn't lucky. He froze to death the following year while making a supply run near Mono Lake.
The mines took some time to take off. The discovery of a rich lode in 1876 led to the development of the Standard Mine, and thousands of people came to the town of Bodie. The population peaked at 10,000 in 1880. The town developed a fearsome reputation for lawlessness, and one legend declared that a young girl, finding that Bodie would be her new home, said "Goodbye God, I'm going to Bodie". The town had its pride, too: an editor of the town newspaper insisted the punctuation was wrong; she had really said "Good, by God, I'm going to Bodie".

The mines were active for years, producing $34 million in gold (at a mixture of prices, $20/ounce in the 1800's and early 1900's, and $36/ounce in the 1930's). The gold is worth a great deal more at today's prices, perhaps $1 or 2 billion. As time went on, gold production waned, and the town began to die away. The Standard Mine shut down in 1913, although sporadic efforts at mining continued through 1942. A disastrous fire in 1932 destroyed most of the buildings in the town (only 110 of the original 2,000 buildings remain).

The gold at Bodie resulted from hydrothermal activity in the heart of a volcanic center that was active between about 14.7 and 8.0 million years ago. The field included at least 20 vents, including four trachyandesite stratovolcanoes. The town lies along the boundary between the deeply eroded Silver Hill and the Potato Peak cones, while the access road to Highway 395 meanders between the Willow Spring and Mt. Biedeman complexes. The sage covered hills reveal little of the volcanic violence that formed this landscape, but they do provide an analog for the appearance of the pre-glacial Sierra Nevada crest. The alpine topography of the present-day Sierra Nevada crest is a very recent geologic event. Without the glaciers, the Sierra Nevada would have been a different place entirely.

Today the town is a popular state park, and it has been declared California's official Gold Rush Ghost Town (as opposed to California's official Silver Rush Ghost Town in Southern California). I have a hard time envisioning a life here. I imagine that it was a relief on the coldest winter days to get out of the house or tent and get underground in the mines where it was warmer. Today, during a visit in the warm summer months, it is a photographer's playground, and an interesting place to learn about ancient Sierra Nevada geography.

Saturday, January 24, 2015

The Sierra Beyond Yosemite: Donnell Vista and Sonora Pass

It's gloomy and foggy, and I haven't seen the sun for days. It's a few more weeks before field season (Death Valley!), but I can't help exploring the sunnier places from warmer times. I'm looking back at the pics from our fall semester where we explored a lot of places in the Sierra Nevada that aren't Yosemite.

That's the thing. Say "Sierra Nevada", and a lot of people will immediately think of the beautiful valley of the Ah-wah-nee, John Muir's favorite place on the planet, and in many ways mine as well. But the floor of Yosemite Valley is about 7 square miles. The national park covers 1,190 square miles (3,081 square kilometers). But the Sierra Nevada? It covers 39,612 sq miles (102,594 km²).  You could hide more than 30 Yosemite parks in the rest of the range. It is in fact the largest single range in the lower 48 states (large mountain systems like the Rockies and Appalachians are made up of numerous smaller sub-ranges).
So we are off onto a short exploration of some of the wonderful corners of the Sierra Nevada that aren't Yosemite Valley. We are following a week's worth of our trips last fall that took us over the range at Sonora Pass and down the east side of the range as far as Lone Pine and Mt. Whitney. We'll also explore the other national parks of the range, Sequoia and Kings Canyon, which we visited on a second trip.
We began our journey in some serious smoke from a series of fires burning through the western slopes of the Sierra Nevada. The drought and the fires have been catastrophic. We made a stop at the Twain Harte Lake exfoliation site. I wrote about it back then, and it was picked up on Reddit and IFLS, links that led to the post being the most read ever on Geotripper (12,400 hits and counting). We emerged from the smoke and climbed the upper reaches of the Stanislaus River, approaching Sonora Pass, which after Tioga is the highest paved highway over the Sierra Nevada at 9,624 feet (2,933 meters). Tioga Pass in Yosemite is 9,943 ft. (3,031 m.).

In a series of ice ages, glaciers covered about 30% of the range, reaching as low as 3,000 feet or so in some of the deeper canyons. Yosemite is simply the most famous of the glacially carved gorges, and many others are of incredible and spectacular beauty. This was not always fully appreciated, and some of these wonderful wild canyons were dammed for irrigation storage and domestic use. Hetch Hetchy is the most familiar, but the canyon below Donnell Vista on Highway 108 has also been inundated. Still, the glacial heritage of Middle Fork of the Stanislaus is evident from the viewpoint. The steep canyon walls of granitic rock and the overall U-shape of the valleys are the result first of ancient river erosion and then modification by thick rivers of ice.

If you look at the second picture above, you can see some unusual looking mountain peaks. Their blocky flat aspect indicates they are composed of something different than the "expected" granitic rock. They are the remains of lava flows, ash flows and volcanic cones that once covered this part of the Sierra Nevada. Indeed, until 9 or 10 million years ago, the Sierra looked far more like today's Cascades Range than the lofty glacial peaks we see today. There were a number of snow-covered stratovolcanoes, but much of the remainder of the range was composed of lower hills. The upper reaches of Highway 108 where it crosses Sonora Pass cut through some of the volcanic rocks.
We stopped a mile or two short of the pass to get a detailed look at the granitic rocks. Depending on the relative proportions of plagioclase and orthoclase feldspar and quartz, rocks may be identified as granite, granodiorite, tonalite, diorite, or monzonite. The rock exposed just below the pass is called the granodiorite of Topaz Lake, dated about 89 to 83 million years ago, during the Cretaceous era. It was intruded in the deep crust about 4 or 5 miles down where it cooled slowly, forming visible crystals of feldspar, quartz and dark minerals like biotite mica and hornblende.

Glaciers scoured the surface of the granodiorite, polishing it and providing a nice view of the structure of the rocks. Some of the orthoclase (potassium feldspar) has formed huge blocky crystals easily visible in the shot below. Even better, during the intrusion process, blocks of the surrounding rock broke off and sank into the magma. Composed of minerals that had higher melting points, it didn't melt, but instead persisted as an alien mass in the granitic rock. Such inclusions are called xenoliths. They provide a peek at what existed here before the intrusion of the magmas.

We drove over Sonora Pass and headed into the barren lands beyond. Our destination was the site of a gold rush, but not the one that Californians are familiar with.

Tuesday, January 20, 2015

The Insight of Werner Herzog (applied to Geology in the Field)

I was wandering through when I ran across this piece about film director and all-around creative person Werner Herzog. Many of his excellent films have had wilderness/outdoor themes, including Grizzly Man and Encounters at the End of the World. A recent book about Herzog has a list of 24 maxims about life and film-making that really struck a chord, and I couldn't help but think how they apply to understanding not just life and film, but also geology in the field. Here, for the fun of it, is an annotated list (stuff in parentheses is mine, and not nearly so wise):

1. Always take the initiative.
2. There is nothing wrong with spending a night in jail if it means getting the shot (sample) you need.
3. Send out all your dogs (graduate students) and one might return with prey (field data that you need).
4. Never wallow in your troubles; despair must be kept private and brief.
5. Learn to live with your mistakes (so true in the field).

6. Expand your knowledge and understanding of music and literature, old and modern (the first researchers who did work in a region had much to offer).
7. That roll of unexposed celluloid you have in your hand might be the last in existence, so do something impressive with it.
8. There is never an excuse not to finish a film (field project).
9. Carry bolt cutters everywhere (!!).
10. Thwart institutional cowardice.
11. Ask for forgiveness, not permission (before you get shot for trespassing).
12. Take your fate into your own hands.
13. Learn to read the inner essence of a landscape (have you ever heard of a better explanation of field work?).

14. Ignite the fire within and explore unknown territory (the heart of the field geologist!).
15. Walk straight ahead, never detour (well, I don't know about this one...).
16. Manoeuvre and mislead, but always deliver (is this advice for teachers??).
17. Don’t be fearful of rejection (for you shall experience it much).
18. Develop your own voice.
19. Day one is the point of no return (so true in the field).
20. A badge of honor is to fail a film theory class (which geology related course should be listed here?).
21. Chance is the lifeblood of cinema (and geology in the field, too).
22. Guerrilla tactics are best.
23. Take revenge if need be.
24. Get used to the bear behind you (no further comment needed).

Thank you, Mr. Herzog for your wonderful work!

4.4 Magnitude Earthquake near Pinnacles National Park

 A 4.4 magnitude earthquake at a depth of about 10 kilometers struck Central California near Pinnacles National Park early this morning. We got an excellent seismic record of the event at Modesto Junior College, as can be seen in the picture above.

Earthquakes of this magnitude are generally felt, but are not likely to cause serious damage. The shake map generated by the U.S. Geological Survey shows that extent of the region where the quake was felt.
ShakeMap Intensity Image
The earthquake looks to have occurred on the San Andreas fault, but in detail it was more than two miles away from the fault. The movement was compressional (a "reverse" fault), rather than lateral, as would be expected on the San Andreas. The odd looking ball below is how seismologists are able to tell the type of causative fault. It is generated by the network of seismometers across Northern California, measuring whether the first wave or motion of the quake is compressional or extensional.
There is a small percent chance (5% or less) that this moderate/small event is a foreshock, or precursor earthquake to a larger event. Such moderate events are good reminders that the people who live in earthquake country must be prepared for large earthquakes. Check your emergency supplies, read up on earthquakes, and be prepared with an emergency plan for your family.

Sunday, January 18, 2015

Giant Alien Space Bear about to Destroy the Earth? Or the Impending Opening of a Great Museum?

What you are actually seeing here is the Science on a Sphere learning area in the soon-to-open Great Valley Museum, and one of the very few blank walls left in the wonderful new center of learning that will serve the northern San Joaquin Valley and the town of Modesto. The new facility was introduced to the community for the first time last night at the "Night at the Museum- the Inaugural Gala" that brought out 240 supporters to a formal dinner and tours of the museum.
The Great Valley Museum has existed since the late 1970s, occupying an old house that originally served as the Modesto Junior College campus bookstore.  The employees and volunteers did a wonderful job of bringing science education to the children of the local community, but they were always hampered by very limited facilities. There has always been a dream of a larger building, but it wasn't until our community passed Measure E in 2004 that the dream could begin to be a reality. The new Science Community Center houses the MJC Science Division with chemistry, biology, astronomy, physics and geology laboratories and classrooms upstairs. Most of the bottom floor of the huge building is now devoted to the museum. The impending opening is a thrilling moment for those of us who have planned and at times fought for a world-class facility to be housed on our campus.
Mrs. Geotripper and I had a marvelous time last night welcoming guests to the Discovery Room, the hands-on area of the museum, which also includes the live animal room. This is the "classroom" for the museum, which will be filled with an array of demonstration materials, books and science based puzzles.
We set out some of the skulls from the museum and school collections, to illustrate some exciting new discoveries that our children and students will be able to make: that our region has an incredible paleontological heritage. The first dinosaur ever discovered in California was found in our county by a 17 year old high school student in 1936. The same young man found a new species of Mosasaur just a year or so later. The skull below is a related species of the gigantic sea-going reptiles that terrorized the late Cretaceous seas. The local species ranged up to 35 feet long.
In the late Pleistocene, the savanna grasslands of our Great Valley supported an extensive ecosystem of grazing animals including horses, camels, antelope, bison, elk, and sloths. They were preyed upon by some terrifying creatures like the American Lion, the Dire Wolf, Sabertooth Cat, Grizzly Bear, and Short-faced Bears (bigger than grizzlies!). Fossils of these creatures have been found in and near our county, but to date few people are aware of this. The opening of the museum will be a big step towards filling in this missing part of our history.
It was through the efforts of our Geology Club and the late Sandy Vanwey (our division's administrative assistant and strong museum supporter) that we were able to purchase a full-scale replica skeleton of a Sabertooth Cat that will grace the entrance hallway along with a number of other symbols for the state of California.
The most important part of the museum's mission is to tell the story of the natural environments of the Great Valley, which includes the northern Sacramento Valley, and the southern San Joaquin Valley. The valley is one of the richest agricultural regions on the planet, but it also still retains some of it's primeval character in a few places, and the museum is equipped as never before to tell that story.
The museum finally has enough space to exhibit the extensive collection of preserved animals specimens in naturalistic settings.
All of the native environments of the Great Valley and adjacent foothills are represented, including grassland/prairie species, riparian species, and the animals of the wetlands and marshes.
There is only one major component of the museum left to build: the Outdoor Education Laboratory, which will be the ultimate part of the learning adventure for the children and students who visit the museum. Imagine seeing the exhibits, and then being able to go outdoors to see many of the species living in a near-natural habitat. Plans call for a stream and pond along with vegetation representing the environments that exist from the mountains to the foothills and the valley floor. The funding for this last part is still pending, but it's been a dream for everyone who has been involved in planning this facility. Proposals for an outdoor lab area date back at least 35 years. It would be such a gift to the community and science education to have that last piece fall into place in the next year or two.
In the meantime, 240 community members gathered together to support and celebrate the impending opening of the Great Valley Museum. Dozens of students and community volunteers were there to welcome them and to help out as servers and guides. It was the biggest event in the 40 year history of the museum, and it was a wonderful privilege to be involved.
The museum still needs financial support to get new teaching supplies and resources that were not provided for in the original bond act. Please consider donating! For more information, check out the museum website here, and the museum facebook page here. It's a great new day for science education on our valley, and it would be great if you could play a part!

Saturday, January 17, 2015

The Way it Was This Week: Winter in the Valley of the Ah-wah-nee

Is there a more beautiful place than this, the Ah-wah-nee, or the Yosemite as some chose to call it years ago? I'm sure that everyone who explores the outdoors has "that place", the spot that represents the highest attainment of their personal concept of beauty in nature. In my life so far, there is no place more beautiful than this.

It isn't just the scenery, which of course is spectacular. It the privilege of coming back time after time, seeing the valley and park in all seasons and all conditions. I've driven through snowstorms, rainstorms, floods, and heatwaves to reach the valley, during every month of the year. I'm guessing I've made the journey 80 or 90 times in the quarter century that I've lived in the adjacent San Joaquin Valley. I've never had a disappointing trip. There is always something new, and there are the old familiar places as well. And much more remains to be explored.
As is clear from the last couple of posts, I was in Yosemite again over the weekend, a sort of last hurrah before beginning the new semester. Despite the lack of snow in the dead of winter, it was a serenely beautiful place. And...very uncrowded. There was some kind of big athletic competition taking place last Sunday or something. The Sentinel Bridge parking area is usually packed with vehicles. Here's how it was on Sunday:

It's a rarely fulfilled desire, the dream to have the most beautiful place in the world to myself. It's just a little selfish too, but hey, I wasn't keeping anyone else from visiting that day. Most seasons it is quite hard to imagine Yosemite Valley as a wilderness. It hasn't been a wilderness for nearly two centuries. But on Sunday, here and there, it was possible to envision the wildness.

After a long dry spell, Yosemite Falls began to flow again a few weeks ago after our December storms. I hope we will have some more storms soon. After a record-setting December, January has been dry. How dry? Zilch, not a drop of rain in the San Joaquin Valley, and none in the 10 day forecast. It is a bit worrisome. Three years of record-setting drought, and this year has the makings of a fourth.

We don't usually stop at the Swinging Bridge Picnic Area, as it is usually packed with people, but not Sunday. It offered wonderful views of Upper Yosemite Falls, and one of Yosemite's less familiar peaks, North Dome (above). I'm pretty sure that if Half Dome didn't exist, or Yosemite Falls, or El Capitan, or Sentinel Rock, or Cathedral Rocks, well then, I am sure that North Dome would be one of the most famous landmarks in Yosemite Valley.
Late in the day we found ourselves in the meadow below El Capitan looking for the free-climbers as they worked their way up the cliff. The few people who were still there were looking up so intently that it took a few moments for anyone to notice that a coyote was standing among us.

I took a moment to look at the oft-ignored cliff across from El Capitan, the wall of spires between Cathedral Rocks and Sentinel Rock. The names are less familiar to most park visitors, Crocker Point, Stanford Point, Taft Fissures, and again, in any other setting, these peaks and cliffs would be the focus of a national park, rather than the relatively unknown cliffs that they are. If the panorama shot below seems a bit less sharp, it's because it was done with my smart phone rather than my usual camera.
It was a beautiful day in a beautiful place. I'm anxious to return.

Where is your most beautiful place?