Saturday, September 28, 2013

Seeing Volcanoes Inside and Out: Exploring California's Volcanoes

Our just completed exploration of Northern California's Volcanoes was a fascinating journey through the interior and exterior of several volcanoes. How do you explore the innards of a volcano? On the one hand, you can do a Brendan Fraser and fall thousands of feet or miles into a volcano ("Journey to the Center of the Earth", a movie I appreciated mostly for the living trilobite in the opening scene). can wait for the volcano to go extinct, be uplifted and eroded for millions of years, and then be established as Castle Crags State Park, and go stand at the viewpoint at the end of the park road. We chose the latter.

The Castle Crags are an especially scenic part of the Klamath Mountains province, a region tucked between the Coast Ranges and the Cascades at the north end of the Great Valley (I've written about them previously, click here to see). Most of the Klamaths are composed of dark colored metamorphic rocks, many of them derived from the mantle, but at Castle Crags the rocks are different. The light colored cliffs are composed of granitic rock (mainly granodiorite, a plutonic rock containing lots of plagioclase feldspar), dating back to around 160 million years ago. The granodiorite was once molten, feeding volcanoes that would have existed several miles above where we were standing. Some of the magma remained in crust, cooling slowly and allowing for the growth of visible crystals. Standing among the granitic towers of Castle Crags is to be standing in the interior of a volcano.
The dramatic spires are the result of exposure at the Earth's surface, and the resulting release of pressure (remember that these rocks formed at a depth of three or four miles in the crust). As the pressure is released, the rock expands and fractures, sometimes in vertical cracks called joints. The joints are exploited by water and ice, leading to the erosion of the steep sharp cliffs.
Sometimes the expansion of the granitic rock is outwards, parallel to the surface of the cliff. This causes fractures that act to remove corners and edges, resulting in dome-like cliffs, much like those found in Yosemite and elsewhere in the Sierra Nevada. This process is called exfoliation.

Even as we stood at the viewpoint appreciating the underside of a volcano, we could turn to our right and see a rather astounding view of the outside of a volcano. A very big volcano. Mt. Shasta is the second tallest peak in the Cascades Range, exceeded only by Mt. Rainier, but it is the most voluminous stratovolcano in the Cascades, and perhaps even the world.
At 14,179 feet, it dominates the scenery from all directions in Northern California. A stratovolcano is composed of alternating layers of ash and lava, but the details of Shasta's structure contradict that description. It is actually the remnant of at least five different volcanoes which developed on more or less the same site. The term "composite cone" is perhaps a more accurate moniker.

Shasta was our next stop of the day. At over 14,000 feet, no roads approach the summit, but in years past a ski area had been constructed at the 8,000 foot level on the south side of the peak. The ski resort was removed long ago because of avalanche danger (a wide swath of fallen trees highlights the hazard), but the paved road remains.

We took the highway out of Mt. Shasta City and headed up the mountain...

Thursday, September 26, 2013

Into the Great Unknown: A Journey Down the Colorado River Through the Grand Canyon (a compilation)

As many of you know, I recently ended a rafting trip down the Colorado River through the Grand Canyon. I just finished a blog series on the journey, and what I've done here is to list the posts in their original order, so that if you want to catch the whole story in one place, this is where you want to start!

Rafting the Colorado River: This is the original post in the series, explaining how I got there, and what I was feeling about a journey that I waited forty years to complete.

Everything you wanted to know about rafting on the Grand Canyon but were afraid to ask: A description of what's involved in a 16 day journey on a river with no stores, bathrooms or trashcans.

Cloudburst (x2)! And Off We Go: Two intense thunderstorms give us a muddy sendoff down the river. Page and other towns got pounded that week by flooding.

Passing through the Permian Period: Our first day on the river takes us through the upper layers of the Grand Canyon, the Permian-aged Kaibab, Toroweap, Coconino and Hermit formations.

Whodunnit? A Mountain Range Goes Missing: The Hermit Formation and Supai Group provide evidence of the existence of a long-eroded mountain in southwest Colorado. And I row a raft for the first time!

Visions of Paradise and a Bug's Horror: We enter Marble Canyon, dominated by the beautiful cliffs and caverns of the Redwall Limestone. A beetle has a tough day.

Exploring 300 million year old and 50 year old caves (and some fossil hunting): We explore Nautiloid Canyon and an exhumed Paleozoic cavern. We also see evidence of a bone-headed plan to dam Marble Canyon. It would have been an unspeakable crime...

Looking for the Rivers within the Rivers of Marble Canyon: The Devonian Period is represented only by the Temple Butte Formation and the exposures are discontinuous because they were originally only the fill within eroded stream valleys. Plus a cool side trip to a small waterfall.

We interrupt this scenery for a very recent flash flood and a biological disaster: The cloudbursts we experienced a few days earlier caused some flooding in the side canyons. And a look at the tamarisk tree, an invasive species.

Catching an Iconic Scene in the Grand Canyon, and a Bi-Colored River: The small Ancestral Puebloan granaries above Nankoweap Canyon are one of the more famous sights on the river, but oh, what a climb! And floodwaters in the Little Colorado change the color of the main river.

Living in a Thomas Moran Painting, and Through a Canyon Storm: A passing storm gives the canyon a dreamy impressionistic look. I get my favorite picture, and I don't get overly wet; there were too many gigantic boulders to cower under.

In the depths of the Grand Canyon there are three more Grand Canyons...Checking out the Supergroup: There is around 12,000 feet of ancient sediments and volcanic intrusions tucked in the deepest parts of the canyon, and they are only accessible by river or long hot hikes. We give them a look.

Journeying to my Roots, and to the Roots of Mountains: We reach some of the monster rapids, including Hance. It was here in 1976 that I was becoming a geology major on my very first field studies class. Who is that gawky thin kid?

Exploring the Heart of a Long-Gone Mountain Range (and words from home): In the bottom of the Grand Canyon there are the roots of a huge mountain range that formed before complex life even existed on our planet. And I hear words from home for the first time in week.

We Run the Big Rapids, Sometimes in Rafts: We run three of the biggest rapids on the Colorado River. I experience something I haven't felt in a long time: terror. We flipped on the biggest rapid and I took a long cold swim through the 10-foot waves and the Rock Garden.

The Aftermath of Chaos...Finding Beauty in the Oldest Rocks of Grand Canyon: The Granite Gorge was a terror-filled place for John Wesley Powell and his men in 1869, but for me on a day after the rapids disaster it was a beautiful place.

The Hidden Places and Putting a Hand Across 1.2 Billion Years: Every side canyon in the Grand Canyon holds a treasure. We visited two, the Elve's Chasm and Blacktail Canyon, and we laid our hands across 1.2 billion years at the Great Unconformity. We also met with a herd of bighorn sheep.

Crossing the Great Unconformity Again...But Which One? There are really two major unconformities in the depths of the canyon (and more than a dozen more minor ones). We got a glimpse of the angular unconformity, and explored the billion year old sills, intrusions of basaltic rock that lined the canyon for a few miles.

A Gigantic Failure Produces One of the Most Beautiful Sights in the Grand Canyon: Slope failure and landslides had as much to do with the formation of the Grand Canyon as the Colorado River. At Deer Creek, a landslide produced one of the most beautiful canyons and waterfalls in the entire canyon.

Mad Cats and Amoebas? Trying to Keep Names Straight in the Grand Canyon: Not many people saw this post for some reason, but Matkatamiba Canyon is one of the prettier side canyons on the river, and one of the favorites of the veterans of previous river trips.

"Disaster" in National Canyon, and the Volcanoes of Grand Canyon: An unbelievable flood last year, and an unbelievable amount of basalt lava in Grand Canyon. And just like that we are facing Lava Falls, the single worst rapid on the river, in turbulence if not length.

Zero Hour at Lava Falls: A story of courage, redemption and the triumph of the human spirit? No. I tried to ride Lava Falls in a raft, but had to swim instead. Involuntarily. See the video version!

Vulcan the fire god says "You call that little piece of concrete a dam?: Lava dams in the Grand Canyon may have stood 2,000 feet high, and may have backed up dams for three hundred miles or more upstream.

Heat...and All Things Beautiful: It was post-Lava Falls, and one of the hottest days we had on the river. And the beauty surrounded us, in the water, in the cliffs, and in the animals.

The Last Day...An Elegy for a Journey, and for a River: I didn't want to leave. The last two miles on the river were the most precious of all, drifting slowly in the current. And then it was over. We derigged and made our ways to our homes, and the Colorado just rolled on.

Wednesday, September 25, 2013

Exploring the Cascades: Home from the Road

 It's always hectic in the week or two after a major field trip, and this week is no exception, so it's a bit more difficult to post detailed explanations. I want to spend some time exploring the Cascades with you all, but for now, how about a short collection of photographs so you can see the kind of trip we had? We did a loop through the Cascades Range and Modoc Plateau of Northern California. Along the way we saw world class examples of practically every kind of volcanic feature there is.

Above is Mt. Shasta and Shastina, a huge composite cone that dominates the scenery of the north state. The mountain tops out at 14,162 feet, and is still considered quite active with eruptions as recently as 1786.
 We spent much of our time at Lava Beds National Monument, a lesser-known park near the Oregon border south of Klamath Falls. It is a fascinating region to explore. It is on the flank of Medicine Lake Highland, a huge shield complex, and it offers marvelous vistas.
Besides the numerous excellent examples of cinder cones and lava flows, it has around 700 lava tubes with something like 75 miles of passageways. The picture below is a shot of Valentine Cave, one of the most accessible of the lava tubes. These tubes are the main plumbing system of basaltic lava flows, and as the eruptions ended, the tubes drained.
We spent a night at beautiful McArthur Burney Falls State Park. An explanation of the falls will be forthcoming in a later post.
Our last exploration was Lassen Volcanic National Park, where we had a chance to explore the largest plug dome on the planet. The park also has some interesting geothermal areas, expecially Bumpass Hell.

We had a great time!

Thursday, September 19, 2013

Hitting the Road: California's Volcanic Lands

There are lots of volcanoes in California, in the deserts, the eastern Sierra Nevada, even in the Coast Ranges, but the most recent and most diverse volcanoes are in the north state, in the Cascades Range and the Modoc Plateau. I'm headed up there tomorrow with my students.
 We are spending our time in Lava Beds National Monument which sits on the flank of California's biggest volcano (surprise! It's not Mt. Shasta...or Lassen Peak either).
We'll have a look at Mt. Shasta, which is the tallest volcano in California, and probably the biggest stratovolcano in the Cascades...
We'll finish our studies at Lassen Volcanic National Park, site of the last eruption in California, in 1914-17. With a bit of luck maybe a small cinder cone will erupt harmlessly somewhere near us along the way! Geotripper will return in a few days...

Monday, September 16, 2013

Into the Great Unknown: The Last Day...An Elegy for a Journey, and for a River

Elegy (from the Greek word for "lament") is a mournful, melancholic or plaintive poem, especially a funeral song or a lament for the dead.

How many ways can I describe the last day of our trip? The word "elegy" came to mind. It was the end of a long but incredible rafting trip down the Colorado River, and I was feeling sad. Sure, I was anxious to hear the news from the family and the outside world, but it was also the ending of one of the greatest experiences of my life. It was the ending of a personal journey, which ventured sometimes into terrifying darkness, but mostly it was a world of sublime beauty, even glory. And... the story was about the abuse and destruction of a river.
We packed at a leisurely pace. We only had a few miles to go, and the Hualapai Nation requested that no take-outs happen before 10 AM.
We set out down the river. We turned a corner and I saw something I hadn't seen in more than a week: a familiar sight. I've been down Diamond Creek several times, and Diamond Peak has an unmistakeable shape, even from the opposite side. To offer a sense of scale, Diamond Peak is only about 200 feet higher than the beach at the beginning of our trip in Lee's Ferry. It stands out in part because it is a fault block that has risen between two fault zones. Erosion along these faults has led to the trick of the topography that allowed a road to be constructed down to the river.
At mile 224 we passed the final rapid, a little riffle that didn't even merit a name. But it was the last one...
And then we entered the last mile or so of river, and it nearly broke my heart. It was perfect. In that moment I wanted to simply float on and on into eternity. Pete stopped rowing and we simply drifted. The river was quiet. A swallowtail butterfly landed briefly on my hand, confused by the bright colors of our clothing and luggage. Pete pulled out his harmonica and played a few tunes.
I wrote in my journal...

I was suddenly wistful, wishing to float down a serene river, at peace, but knowing that it is never truly serene. There are those perfect moments that make everything worthwhile but around the bend there can be excitement, action, and even terror. But peace returns, and we recover our sense of well being.

Such beauty in such a savage land. Without the river, life would be barely possible for a person. Too far between water sources when it is so god-awful hot. The hike yesterday across the Tapeats ledges could have been unbearable without soaking in the cold water first.

But along the string of life-giving water, the beauty is overwhelming. Every side canyon would be worthy of a national park all its own. I found myself thinking 30 Yosemite Valleys strung in a line would equal the Grand Canyon.

I don't know that I will be back. I faced the big waters twice and made it through, one time in terror, and the other less so. But I enjoyed the rapids a bit less afterwards...

...but nothing can take the place of drifting down the placid parts of the river; seeing the herons and bighorns, and I'll never forget the sounds of the canyon wrens. I would do it for that...those parts will always live on in my memories.

The cliffs would glow red in the pre-morning hours after the stars disappear. The red fades into shadow, and then the sun lights up the cliffs in blazing orange. The river was always brown but in the shadows of evening and morning, it reflected the lights of the cliffs above...wonderful moments.

I took one last video as we drifted...


And then, a strange sight, a big orange ball and a cable strung across the river. It was the gaging station at Diamond Creek. It was a reminder that this was a heavily utilized river that had to be measured and controlled. There was a feeling on the entire trip that the river we were traveling on was not "right". It was far too cold for a desert summer, and it ran too high for any snow-fed river in August. The disappearing beaches demonstrated that the river rarely flooded anymore.

It's hard to imagine the difference between this river and the river that was experienced by John Wesley Powell and his courageous men. And it was almost entirely due to the construction in 1963 of the monstrosity that flooded a precious gorge called Glen Canyon. And the sewage lagoon that formed behind the dam was named for Powell. I don't think he would have been pleased. He recognized sooner than most the problems that would lie ahead for the millions who would come to depend on an inherently undependable river. The lake that bears Powell's name may never again fill if the predictions of the climate scientists come to pass.

The river will return. And it probably won't take as long as it did when lava flows temporarily stopped the flows of the river. The dam is built in unstable porous rock, and it almost failed catastrophically in 1983, due in part to the arrogance of the dam engineers. It ultimately must fail, probably within a few years of being abandoned by the society that maintains it. Ultimately the river will return to something of its former self. Time is all it needs.

The gaging station also meant that our time was almost up...

A beach came into view, with trucks and giant pontoon boats. We waited until the other boats left on their journey to Lake Mead and pulled off the river for the last time.

Rigging the boats at the beginning of our trip took parts of two days. The de-rigging took an hour or less. No one wanted to hang out on the river in the growing heat of the day.

All of the material we began the trip with came off the river, although some of it had been, um, "transformed". A few items, most notably my hat, gloves and a guidebook were still in the river somewhere. Oh and a tent that blew away several days earlier.

I finally had a look at the unadorned raft that had been my home for the last two weeks. We developed a luggage line and got all our gear onto the truck; we would unscramble it in much more comfortable weather in Flagstaff at an elevation of 7,000 feet. We piled into the truck and a van and set out on the bumpy 20 mile drive to Peach Springs where we would rediscover ice cream and flush toilets. A 90 mile drive to Flagstaff followed...
...our trip was over.

I hope you have enjoyed following our journey. Thanks to all those who traveled with me, and especially my brother and his family who invited me to come along. Thanks to Pete, who was a wonderful boatman and traveling companion. They were wonderful people to travel with! Thanks to Barry, Bev and Jeff, who pulled me from the river, sometimes more than once.  And thanks to all the river runners who have clearly worked to keep the river clean and wild.

Look for one more post in this series, a compilation of all the posts on the journey, and maybe a few final thoughts.

Into the Great Unknown: Heat...and All Things Beautiful

It was our last full day on the Colorado River through the Grand Canyon, the Great Unknown as John Wesley Powell called it in 1869. One full day, and one more night on the life-giving stream of water through one of the spectacular canyons on Earth. We had eighteen miles to go, from our camp at Mile 202 to 220 Mile Camp (it was clear that the geographers were running out of names for the features in the canyon; it's that big).

It was a day full of the best things the canyon could offer. But it was also hot. Blazing oven hot. Merciless sun beating down hot. In other words, a normal summer day in the Inner Canyon. The thing is, we had already experienced a few hot days on the trip, but not quite the kind of 115 degree days that we were warned about in the training materials. I don't actually know how hot it got, but in my memory, it was the hottest day of the trip.

They said a few things in the training videos for rafting the river. To drink before you get thirsty. To drink a gallon a day. To always wear a hat. Seek out shade when possible, and don't hike between 10 and 4. They said it takes a human body about two weeks to acclimate to extreme hot temperatures, meaning a river trip was not long enough to do so.
We were seeing all kinds of adaptations to the heat as we explored the area around our camp during the relatively cool morning hours. We had dropped nearly 2,000 feet during our two weeks on the river, and the desert vegetation was characteristic of the Lower Sonoran Life Zone (or whatever the biologists are calling it these days). Cacti had been rare in the upper reaches of the river, but now they were common.
There were a few shrubs with their characteristic waxy leaves taking advantage of the recent storms by putting out a few flowers.
Best of all were the ocotillos that we had been seeing for the last two or three days. They too had taken advantage of the recent storms, and had put out thin leaves along their green branches (most of their food production happens in the branches rather than the leaves). There were none of the beautiful  red flowers (we'd need to be here in May for that).
We took advantage of the relative cool of the morning to search out some pictographs that were said to be up in 202 Mile Canyon. It took a while (which is why I had given up and photographed the plants instead), but eventually we found them. It was a small measure of the rate of geologic change that some of the blocks of rocks containing the rock paintings had tumbled down from the ledge.
Once the sun reached our boats, we set off down the river. We continued to see remnants of the lava flows that had once produced high dams, and which had continued downstream for many tens of miles (above).
We also saw another gigantic landslide that had involved the entire canyon wall (above). Lava flows aren't the only things that have produced dams on the river. As noted in an earlier post, landslides have altered the course of the river a number of times.
We saw more evidence of human occupation in the canyon. We discovered roasting pits in several of the debris fans at the mouths of some of the tributary streams. Along with the cracked and shattered rocks we found bit and pieces of pottery.
A short hot hike up Indian Canyon offered a fine view up the river. But it was hot and there was no shade. I shiver to thick how quickly I would have been in trouble here had I not been carrying a quart of water at all times. I was drinking at least a gallon and a half of water on days like this, and when it got too uncomfortable, I could splash in the river water to cool off. Despite being 200+ miles downstream from Glen Canyon Dam, the water was still in the mid-to-upper fifty degree range.
The scenery continued on a grand scale, with high cliffs at every turn. We saw another bighorn along the riverbank. It was as if the river was giving us reminders of why the canyon was precious. And that was the way I was feeling. This was the last full day, and while I was wanting to see the people I was missing in the outside world, I was also feeling like I wanted to hold onto these incredible experiences that I felt were enriching and transforming my life.
We crossed the Hurricane Fault again, and the ancient Vishnu Schist was exposed at river level once more.
 In the intense sunshine, the polished surfaces of mica, quartz and feldspar reflected brightly.
 It's amazing what the silt-filled water can accomplish!
 As we searched for (unsuccessfully) for a shady lunch stop, we encountered an unusual looking ledge of Tapeats Sandstone on the left bank.
The top of the ledge had been scoured and eroded by river currents, and it looked recent, yet the bench was 15 or 20 feet high. It looked extremely fresh.
 At the lower end, there was a strange orange-colored edifice called Pumpkin Spring. It was a warm spring deposit that was redepositing travertine that had been dissolved from the overlying limestone formations. The heat probably came from nearby active fault zones. The water was green and uninviting. The river guide suggested not drinking it because of high concentrations of arsenic (is that a poison or something?).
 We set up a canopy and crowded underneath it to eat lunch. There was a hot breeze blowing so the shade barely helped. Unfortunately the wind was trying to destroy the umbrellas that most of the boats had, so there was really no place to retreat from the sun. For pretty much the first time voluntarily, I spent most of the time soaking in the river as long as I could stand it (cold!), then getting out and warming up until I was dry and hot, and then getting back in the river!
Despite the heat, we wanted to check out the unusual terrace in the Tapeats Sandstone that we had just floated by. We grabbed some water and headed back up the canyon. The edge was pockmarked with huge potholes, many of which had carved right through the rock, forming little tunnels and caves. Many of the potholes still had the pebbles and cobbles that had carved them.
It turns out the terrace has been flooded by river water in historic time during the big spring floods, but only rarely since the floodgates of Glen Canyon Dam shut in 1963. The dam is still altering the river, even 200 miles downstream.
 We made one more stop that afternoon, at Three Springs Canyon. Like so many tributaries, it had a small stream of clear water that we could use for drinking. Some of the crew pumped the water filters while others hauled the five-gallon buckets down the trail to the boats.
 Yours truly found he could make a human dam across the trickling creek and have a nice bath.
It was the hottest part of a very hot day, and a hot breeze was blowing up-canyon. No one felt like rowing against the wind, not in the hot sun without the umbrellas. We holed up in the shade behind a ledge at Three Springs Canyon for quite awhile, letting the afternoon shadows extend across the canyon a bit.
 We arrived at our site for the night at 220 Mile Camp. As if to make some kind of point so late in our trip, it was one of the most beautiful camps of the trip. There was an island of Vishnu Schist in the river decorated with a few wispy tamarisk saplings. Our camp was in the shade (relief!), but the sun was shining brilliantly on the cliffs across the way, reflecting on the river.
The view upstream was gorgeous as well. At this late point in the day, no one else was on the river; the feeling of isolated wilderness was complete. It was strange to think that only six miles away a road reached river level, and that we would be driving out of the canyon in the morning.
We drank the last of the beers and the sodas, ate most of the remaining food, and sat in the warm air watching the sunlight drain away from the cliffs as night fell. After a while, a cool breeze wafted off the surface of the water.
The moon was a touch higher in the sky than the previous evening (it always happens that way), but it soon dipped below the cliffs. It was the 11th of August and the Perseids Meteor Shower was scheduled to debut in the night sky. It did not disappoint; as we talked and sang and played the guitar, I counted maybe a hundred shooting stars, some of them blazing a trail all the way across the sky. I had been turning in early on many nights of the trip, but on this night I was still awake staring at the show in the sky until well past midnight. I'll not forget it any time soon. I didn't want the night to end, and yet I did.

Tomorrow we would be back into civilization, and I would be starting the journey home...