Thursday, March 31, 2022

Those Things We Scientists Never Talk About...

I am often asked if I have run across strange phenomena in my travels. My journeys take me to many different places and environments, and frankly, some things have been known to happen. It is not one of those things that we earth scientists like to talk about, and one might be tempted to say, really that we could say, we have been hiding this knowledge from the public for years. I don't think that conspiracy is the right word here, it's just that we don't think that the public at large should be led to believe in the existence of these things.  That there are things out there...
They're seen in caves in and around Mt. Shasta and Medicine Lake Highland. If you are in the dark long start to see the lights. They float through the open spaces of the lava tubes, the long passageways produced when subsurface lava flows drain away from openings downslope. They aren't easy to photograph, but I once hid behind a pile of broken rubble and left the shutter open. The spectral lights appeared around the corner and silently passed by.
There are stories about the Atlanteans and Lemurians inhabiting the underworld of Mt. Shasta, and incredibly detailed descriptions of how they carved the tunnels of their underground cities. Being the hard-boiled logical scientist I am, I am not unreluctant to declare that this is the only possible explanation for these lights. The underground civilizations of beings who lost their islands in the Mediterranean Sea and Indian Ocean tens of thousands of years ago in giant cataclysms and who came to Mt. Shasta and Medicine Lake Highland to some might make so much more sense than anything else that could explain the images on my digital camera.

In Avril Erste, there is a colleague who can back me up on all my assertions. Avril has seen these same lights in other caves, too, much farther south than Mt. Shasta. They're in the caves of the Sierra foothills too...
I want to believe...

Friday, March 25, 2022

A Tale of Two Pullouts: Yosemite Valley From a Different Angle

El Capitan and the Merced River from the east

I know that I am truly privileged living as I do only a two-hour drive from one of the most sublime places on Earth, Yosemite Valley and the Sierra Nevada. We head up there two or three times a year, sometimes with students in tow, and sometimes on our own, so in 30+ years we've been there at least 100 times.

And I never get tired of it.

Part of the allure is seeing the seasonal changes. Winter provides the coating of snow, while fall provides the changing colors of foliage. Spring offers surging waterfalls and wild river flows. Summer provides...well...crowds, but also nice moments in places we learn of where the crowds can be avoided. We have favorite meadows and lakes for instance where people rarely stop. No matter when or where we visit, there always seems to be something new or different.

The Cathedral Spires are tucked away on the east side of the Cathedral Rocks at Bridalveil Falls
I know how it is if one gets to see Yosemite Valley for the first, and maybe only time. I've had that experience at so many other places around the world. The time available may be very limited, one may be part of a tightly controlled tour, and no one wants to miss any of the most famous views or hikes. And so it is that there is the required stop at Tunnel View, Bridalveil Falls, Cook's Meadow for the view of Yosemite Falls, and maybe Ahwahnee Meadow for a view of Half Dome. The walk to Lower Yosemite Falls, or Nevada Falls. And the Visitor Center. It makes for a full day, and a fulfilling day too. One of the most spectacular days you might ever experience.

And I never get tired of it. I'm perfectly happy to hit those same spots on my 101st trip to the valley. The season, the time of day, and the weather all conspire to make each stop a unique experience of wonder. But sometimes there are changes of a different nature, and that makes some trips really memorable. That is what today's collection of views is about.
Sentinel Rock rises above the south side of Yosemite Valley across from Yosemite Falls
Since the time that Yosemite Valley became a park, suppression of all forest fires has been the official policy. It was not however the natural condition of the parkland, nor was it the normal condition of the valley floor over the last few thousand years when it was managed by the original inhabitants of the region. 

The Ahwahnechee people, with roots among the Miwok and Paiute peoples of both sides of the Sierra, depended in large part on the acorns of the Black Oak and grazing animals like deer or bighorn in Yosemite Valley. It was in their best interest over the centuries to allow fires to burn through the valley floor and hold the quick-growing conifers at bay. When the park administrators put an end to the fires, the pine and cedar trees choked out meadows (only 65 acres of the original 750 acres of meadows remain) and grew into impenetrable thickets, blocking views of the canyon walls above.

What's worse is that choking off small fires can cause a buildup of fuel in the forest that could only lead to much worse fires than usual. This was always a danger, but it is far more hazardous today in a time of warming climate and extended droughts. Every Californian is fully aware of how wildfires in the state have morphed into monstrous events without parallel in written history.

The National Park Service has come around in their fire philosophy, especially after extensive fires a few decades ago in Yellowstone and Mesa Verde National Parks. They have instituted new policies of prescribed fires and selective tree removal to make the parks safer, but also to enhance the experiences of park visitors. In what way? The views.
The distinctive profile of the Three Brothers is the result of parallel jointing, or fractures in the granite that occur as the rocks are exposed by erosion
There are the parking lots that attract the majority of park visitors, but on the roads that loop around the valley there are many small pullouts, enough for perhaps three or four cars. In years past there seemed no real purpose for them, as they were surrounded by thick forest and offered no views or trailheads. On our visit a week ago, I found that two of those previously uninteresting pullouts had had the forest thinned out, and that they now possessed some outrageously spectacular views! The familiar iconic cliffs were there, but from angles I had never really seen before. In particular there was the long vertical cliff extending east from El Capitan, a view of the rarely seen Cathedral Spires (as opposed to the Cathedral Rocks at Bridalveil Falls), the vertical pillar of Sentinel Rock (often missed by people staring at Yosemite Falls), and the Three Brothers, which have never really had a designated viewpoint and are usually hidden by the tall trees. Upper Yosemite Fall was visible as well, perhaps farther away, but how many of you Yosemite veterans can recall seeing the falls with not a single other person in sight?
Yosemite Falls from a pullout west of Swinging Bridge
We had a leisurely lunch at the pullouts and wandered about taking pictures, and only two or three cars pulled off the road, and no one else actually got out. Except for the noise of passing traffic on a crowded Sunday afternoon, we literally had the best of Yosemite Valley to ourselves.
Prescribed fire in Yosemite Valley, with Half Dome and Clouds Rest in the distance.
We stayed at the park through Monday morning, and when we stopped by Tunnel View we witnessed another chapter in the new fire/forest regime: the ignition of a prescribed fire. It was done in March because the ground was still damp enough to prevent the uncontrolled spread of the fire. If you are on Facebook and would like to know more about forest management in Yosemite, check out (1) Yosemite Fire and Aviation | Facebook.

Monday, March 14, 2022

The Merced River of California: A Place for Wildflowers and Landslides (and Yosemite Valley)

The Merced River is one of California's extraordinary waterways. First and foremost, it is the river that carved Yosemite Valley, which is one of the world's most spectacular valleys. You may be forgiven for thinking that glaciers carved Yosemite Valley, and they certainly had an important role, but it was learned years ago that the heavy-duty work of carving the 3,000-foot-deep gorge was done before the ice ages ever arrived 2 million years ago. The glaciers certainly modified the shape of the valley, but the depth was first achieved by water flowing over stone.

We spent a couple of days in the valley at a time when the crowds are few, the snow is in retreat, but the green of spring is still some weeks away. It was neither winter nor spring, but the waterfalls were full and the birds were becoming more active, and we had a marvelous time. This morning brought a sight we had never seen in dozens of previous visits though: the beginning of a controlled burn. 

The native Americans who first lived and hunted in the valley knew the value of fire. They would regularly set fires to the forest and meadows to clear out undergrowth and maintain the extensive meadows on the valley floor. When the park was established in 1890, fire became the enemy and any hint of a fire was quickly put out. As a consequence the meadows shrank from the original 750 acres to less than 100 today. The forest became choked with young trees, and fuel built up on the forest floor. It was a major disaster-in-waiting. In recent years, the park management has sought to return the valley floor to something resembling the environment that existed prior to European colonization. Some of the activity has involved some controversial logging operations, and the controlled burns can interfere with the experience of visitors, but the eventual changes will be a vast improvement over present conditions.
One of our real motivations for the trip actually involved a different part of the Merced River, the deep canyon downstream of Yosemite Valley. The Merced River canyon downstream of the lowest extent of the glaciers is a different place entirely. The vertical walls of glacially-shaped granite give way to a V-shaped river valley covered by vegetation that often obscures an extensive belt of metamorphic rocks that are hundreds of millions years older than the granite intrusions.
While not as "spectacular" as Yosemite Valley, the canyon is not without scenic wonders. Indeed, for a few weeks in the spring the walls of the canyon can explode into a color palette that puts the gray granite cliffs of Yosemite Valley to shame. Wildflowers like golden poppy, lupine, and fiddleneck and many others can cover the slopes from the river to the canyon rim.
The climax (if it comes; it's been a dry year) lies a few weeks in the future. But here and there, the slopes provided a hint of what is to come.
The redbuds are just getting started with their not-red buds. More of a pink/purple shade if you ask me.
The slopes of the gorge are also an environment adapted to fire. In the Mediterranean climate the winters are cool and wet, and the summers are very hot and dry. Fires have always swept through the gorge, but those of recent years have been particularly intense due to the extended droughts and higher temperatures due to global warming.
Ultimately fires are a necessary part of the environment, but they can seem particularly tragic in the short-term, especially when people are killed or developments destroyed. The wildflowers play an important role in the recovery of the slopes, as they are pioneer species that help rebuild nutrients in the soils that can assist in the return of the shrublands and forest. The seed may lie in the soil for years before conditions are right for germination, and then the barren slopes come alive with color.
The Golden Poppy is a particularly visible part of the wildflower population. It is California's state flower, and it was a great choice because it thrives in many if not most of California's diverse ecosystems. They're common in the Coast Ranges, the Great Valley, the Sierra Nevada foothills, the volcanic landscapes of the Cascades and Modoc Plateau, the mountains of southern California, and in the Mojave Desert (the Antelope Valley Poppy Reserve is spectacular right now, from what I am hearing). They can also grow on California's strange serpentine soils that most plants cannot tolerate.
A final sight were looking for was the Ferguson Slide. The slope at this particular turn in the river was always unstable, but in 2006 the entire slope slide downwards and covered the highway with tens of thousands of cubic yards of boulders. Far more debris remains on the slopes above, and for a time there were fears that a truly massive slide could block the river and form a natural dam with a lake several miles long. A number of "fixes" were considered, and in the meantime "temporary" bridges were built to provide one-way access on the busy highway. Temporary in the sense that they have been there for fifteen years and counting.
In the end they have decided to build an "avalanche shed", but for rocks instead of snow. The cost is in excess of $180 million (which at the time was about the entire budget for Yosemite National Park). Nature doesn't take kindly to attempts at altering the physics of the slope, and some of the first attempts at stabilizing the upper slopes were laughably sloughed off. There was an earlier coating of the fencing material that was destroyed soon after application. They spent several years carting off nearly 150,000 cubic yards of metamorphic rock and have again tried to fence in the slope. It will be interesting to see what happens when the construction of the shed actually begins.
The photo above is the most comprehensive picture I've been able to capture. I made sure to be last in line when the traffic light changed and allowed the line of cars to follow the one-lane road. I lingered a few seconds to get the shot, and hurried along to make sure I didn't run into oncoming traffic on the narrow bridge. 

There are many more stories to tell of the Merced River downstream, where it flows through the Mother Lode, the places where it lies trapped in the waters of Lake McClure and Lake McSwain, the dredge pits at Merced Falls, and the slow journey across the floor of the Great Valley where it ends in the San Joaquin River. Those will come another day!