Saturday, June 22, 2013

Yosemite version 2

Every year, the Caltech Y runs a student trip to Yosemite National Park. I previously did this trip in 2011 and had a terrific time. J and I completed the mist-panorama-4 mile trail linkup, which was absolutely incredible. An account can be found here:

But I get ahead of myself! A few weeks ago I had been recruited (with no difficulty whatsoever) to join the trip, and to help out as a leader. As the trip necessitated three days away from my glowing computer terminal igloo, I made sure to get a bit of extra work done first. One bug after another crumbled beneath my comprehensive understanding of kdbg, and by the time I slept it was 4am. Not to worry, I set my alarm for 5:30. That way I'd have time to get up, eat breakfast, cycle to work, finish packing my stuff (mostly already shuttled in place over several days), and amble slowly over to the bus on Wilson. Come 5:30, evil me said "You have got to be kidding", rolled over and went back to sleep. The end.

Wait! There's more! I woke up at 6:30 in a blind panic. The bus was loading at 7am, and my best time up the hill to Caltech was about 29.9 minutes. In one fluid practised maneouver I leapt from bed into my clothes and out the door onto my already zooming bicycle. It was so early the air was fresh, the lights quick, the traffic slightly less suicidal than usual. I beat my personal best door-to-door by about 2.5s, which nearly reduced me to tears. But no time for disappointment at my lack of athletic prowess, those days are far behind me.

Into the office, check the simulations are still going (they are!) throw everything into several waiting bags, and trot out and down the road in the direction that a leaving bus would be taking. 

At first glance the meeting area is suspiciously empty. But then I spotted a tumiculus of spare sleeping bags and pads and breathed a sigh of relief. 

It turned out the bus driver had gotten lost twice and we didn't leave for another hour. I chowed down on a cliff bar and helped man a chain gang loading essential supplies of firewood, bagels, and powdered hot chocolate. At this point it should be noted that the bus was festooned with a giant advertisement for a factory outlet featuring a model's face about 10 feet high. The interior of the bus was thus somewhat dim. The seats were comfortable and the aircon highly crispy.

Before long were zooming down (up?) the 5 toward destiny. Any thrill we had at our driver making up for lost time on the expressway soon turned to adrenaline and a confused limbic system as he  flew up the twisty mountain roads through Yosemite National Park. At this point I thought I was the only slightly apprehensive passenger, though soon after a few people were actually ill from the curves. Only once before had I driven on a road where the speed limit was regularly exceeded by a factor of two. On that occasion, I had been driven along the Chuysky Trakt in the Altai Republic of Russia in a worthy Toyota Corolla. After several hours of tentative stabs at the language barrier, he managed to communicate that he wasn't afraid of dying in a car accident, since his lung cancer was already pretty bad.

On this occasion, however, we were in a rather large bus. True, the road was better, and the brakes worked, but ...

Soon enough we popped out into Yosemite valley itself. This is one of the few places on Earth that truly has to be seen to be believed. Not that that will stop me from uploading several thousand photographs, of course. The scale is beyond comprehension. I will now refrain from writing a small book on the geology of the gorgeous granite walls, and proceed to what happened next. 

We were dropped off at Camp 4 on the northern side of the valley. Z, J, D, and I (being the 'leaders') quickly performed a headcount, and then set off en masse for Columbia rock, one of the more accessible lookouts over the valley. I spotted a blue jay, and later one got close enough for some pretty nice photos. We attempted to spot some climbers on half dome, without success. There must have been some though, as we met them the following day.

Columbia rock is about 1.5 miles (2.5km) from the trail head. A few of the more enthusiastic types (including your humble narrator) set off further up the trail towards Yosemite falls, the tallest waterfall in North America. 2 years ago, it was flowing like nothing else, and we were all drenched well before we even saw it. This time, however, I was able to locate a little side trail and we climbed out on a pile of old talus underneath the falls. The setting sun caught shoots of water as they cascaded from the top of the escarpment. One of my co-conspirators wanted to scramble a bit more toward the cliff face, but we quickly found the going tougher than it looked. We turned back, and after a quick jaunt up the trail for a better view, returned to the valley floor in time for a quick dinner. We piled aboard the bus and our return trip began. Fortunately I was so tired I fell asleep and thus avoided the spectacle of the bus overtaking everyone on the way back down. When I woke up, however, there was a perfect profile of my face printed on the window from my whole body being slammed against it on every other turn. I was, it has to be said, rather tired.

Back at the campsite, we unloaded the bus and proceeded to set up camp. I quickly located the only viable hammocking spot, moments before a tent composed of highly snore-prone-looking people set up right next door. Fortunately I was able to stockpile a few boulders to take care of any eventualities. 

Later that evening we drank our all-important powdered beverages, sat around a campfire and talked. I'm inclined to agree with Kim Stanley Robinson when he says that, dollar for dollar, sitting around a campfire with friends is by far the most blissful thing possible to do. I packed my bag for the following day (rain jacket, first aid kit, 2L of water, a few gadgets, and my own body weight in nuts), and retrieved my trusty binoculars. The rapidly waxing moon rewarded us with a long line of craters and mountains, and not far away Saturn's rings awaited anyone with the focusing ability of a brain surgeon and the hands of a biathlete. At length we retired for the evening.

I hadn't used my hammock in quite some time. One bug/feature is that the processing of getting all the blankets and sleeping bags in the correct position to avoid a freezing shoulder in the middle of the night involves dozens of sit-ups, effectively pre-warming the volume in a satisfying way. Nevertheless, my sleeping bag was insufficiently lofted as I had not unpacked it since Death Valley and I was, at times, rather chilly.

The next morning I became awake at about 6:30, extricated myself from my sleeping bag, sat up and stuck my legs out through the boarding door. From here I was able to retrieve my sandals and stepped down onto the ground. Turning around I packed the appropriate stuff away (with full head room, of course), and had some oatmeal and sugar for breakfast. Before long the bus had turned up and we piled on. This time heavy traffic prevented our rather gung-ho driver from breaking any more records or trees, but that didn't stop him tail-gating like crazy. 

This time, he dropped us at Curry Village. After a quick bathroom break we set off for the Happy Isles/Mist Trail. We gave everyone some tips for good trails to try, but discouraged an attempt at the Panorama trail. Two years ago, a few people went very slow and held everyone up for hours and it was no fun for anyone.

The water above Vernal Falls was not raging above the safety railing this time, but a few signs asking hikers to keep a look-out for the as-yet unlocated remains of someone swept over the falls reminded us that the water was still dangerous.

From here the trail proceeded up a series of lung-bursting switchbacks hewn from the living rock. As we passed the meadow below Nevada falls J cried out "Bear!". I had completely missed it, but about 4 meters ahead was a juvenile black bear (though he was brown). He took a good look at us before ambling off into the scrub. Sadly chasing him with my camera was a low priority and we continued up the trail. As always, I wore my trusty expedition sandals, and they performed admirably. Over the entire day's 18 miles (29km) I skidded only twice.

At the top of Nevada falls, J had a surprise - some permits for half dome! The group split as a few others headed for Panorama point instead of Glacier point, and J, D, D', and I headed up the little Yosemite valley toward Half Dome.

The trail circled Half Dome to approach it from the north. Along the way we had excellent views of the granite monolith from all angles. It's vaguely dome-shaped, and only a small amount of the original pluton has fallen away to reveal the famous face. It has a storied history, and is one of the classical big-wall rock climbing ascents. Earlier this year my friend H and his partner V set a record on the sheer face of Half Dome: Slowest In A Day. I think the current speed record stands at a little under 90 minutes, when Alex Honnold climbed it without ropes. Two days is a more typical time, and we passed a few climbers on their way down.

Just before the edge of the treeline, we verified our permits with the ranger, who warned us about a population of brutal carnivorous marmots on the summit. Apparently there's also some peculiar species of salamander up there as well. We took a few moments to eat a snack, catch our breath, and admire a few horses who were taking a well deserved break in the clearing. From here the trail zig-zagged up the northern face of the sub dome, a small outcropping below the main dome. After a bit of haphazard trail findings, we popped out onto the saddle, and finally our main prize and last challenge lay ahead of us: the cables!

Half dome is frighteningly steep even on the non-sheer sides. Indeed, it was thought unclimbable until a bolt ladder was drilled in 1875. Today there is a pair of steel cables on poles that run up the 45 degree slope for about 400m. We had gloves to aid our ascent, but the rock between the cables was worn smooth by millions of shoes, so an element of diceyness remained. I was surprised to learn that only 6 fatal falls from the cables have occurred since 1919. About half the hikers were clipping into each section of the cable, and more than a few people turned back either at the bottom of the last pitch or else shortly thereafter.

I checked the velcro on my sandals, and the four of us climbed slowly to the top. At 8800 feet, you feel the altitude. After an eternity, we mantled the last ledge and the trail leveled out - we were at the summit! We found a nice pile of granite flakes next to The Visor - a rocky protuberance that several hikers decided would make a good photo opportunity to clamber out onto. Personally, I put my feet up, opened my sandwich bag, and proceeded to envelop thousands of calories with gusto. 

Before long a curious squirrel had given way to a practised pair of marmots. With fire in their eyes and death in their teeth, they flanked us from all sides and repeatedly snuck between fissures in the rock to try and pinch our food. Without success, I might add. By now it was getting late, so we had a quick explore, took a photo doing handstands, and then approached the cables once more with some trepidation. My gloves were not of the high-friction variety, and I was not equipped with a harness or rock shoes. I decided to cling to the uphill cable on the theory that if I slipped, I would pass a cable pillar from the opposite cable to which I might be able to cling. Fortunately, I found that I could use friction to allow me to walk backwards down normal to the surface, thus minimising the possibility of a foot slip. At some point I noted that my coordinate system had changed. Up and down were now separated by a mere 90 degrees. Opposite of down was out, and opposite of up was death.

As we descended a few people dropped water bottles which skittered down the face at alarming speed. Meanwhile, a kid above me decided that the best method for descent was the controlled slide from one rung the next. Admittedly he did do it well, though I was concerned that if he slipped he would probably hit me. 

Fortunately, we reached the base without incident, and I stowed my gloves as my hands began to swell from the work. The walk back was much like the walk up, only in reverse, save for a deer, a snake, and a grouse we encountered along the way. At the top of Nevada falls we realised that neither of our two options would return us to the valley floor in time for dinner, so we opted for the less steep but longer John Muir trail, which wound around under a series of cliffs with curtains of water dripping from above. Unfortunately this trail was also popular with horses, so we spent much of the time dodging their excrement. Once we got onto the Happy Isles trail, D and I were sufficiently energetic that we ran all the way back to the road. I also decided to reward my long suffering feet by doing the last few miles barefoot. The ground, as usual, had an intoxicating mix of temperatures and textures. 

Back at curry village we corralled the troops, refilled our water bottles, and boarded the bus back to camp. We didn't lose anyone!

After another hair raising bus ride (not for a lack of asking the driver to slow down) we arrived back at camp in a cloud of smoke from burning brakes and got ready for the evening. I repacked some gear, then fetched my pajamas and made for the river. Running a few inches deep and COLD, I found a secluded rock and proceeded to ensure I did not inadvertently remove any rocks (especially the tiny ones encrusting my feet) from the park, and had a jolly good sponge bath while I was at it. Meanwhile a water skater came over to say hi. 

Thus invigorated and somewhat lighter for the lack of dirt, we set a fire, I ate a bunch of my leftover food in lieu of dinner, and we conspired with our friendly Caltech alum D for the following day's trip to Centennial grove. I set up a time lapse, stared at the burning embers, and speculated wildly about future developments of space technology. 

That night my sleeping bag had fluffed up to the point that not only was I not cold, I even inhaled a feather! The hammock as usual proved to be comfortable and prone to excellent, vivid dreams.

The next morning I retrieved my gear from the bear-proof box, packed up my gear (except for all the warm stuff which I was still wearing) and helped to put away the group gear. Before long the bus was loaded, the last stragglers had boarded, and our friendly Caltech alum had arrived to lead us to the place. At this point the plan we hatched the night before went into action. D drove at a sensible pace all the way. Our driver, now adorned with at least 2lbs of silver chain and crucifix, was gnashing his teeth as corner after corner passed on all four wheels. J and I rubbed our hands together with glee, and the other 23 stomachs breathed a little easier.

Arthur Fleming (after whom Fleming Hovse is named) was an early trustee of Caltech, back when it was called Throop college. He made his fortune in timber, and when he retired he donated his estate, including the timber operation to Caltech. After his death, all except one 20 acre parcel was sold, and today we were visiting this plot of land, which contains a grove of 5 giant sequoia trees. Before long we'd managed to find the place (it involved a bit of bush bashing) and had seen the giant trees for ourselves. Many more of their ancestors were lying around on the ground, which afforded excellent roads through the underbrush. The largest of them was about 7m (22') across at the base, and had a hollow in which six of us stood with plenty of room to spare. I also took a moment to appreciate more than a few wildflowers which were blooming at this time of year. 

After a quick bite for lunch we reboarded the bus and headed for LA. With just one brief stop at Tejon Ranch, we were back in Pasadena by 5:30pm. We unloaded the bus, kissed terra firma, and laid out a few wet tent-flies to dry. 

Another trip over. Yosemite valley remains one of the most extraordinary places I have ever seen.

Wednesday, June 5, 2013

Death Valley field trip

Another term rolled around and it was time for a geology field trip! This time, to Death Valley. Despite living in the states for nearly 3 years, I'd never explored Death Valley, and was looking forward to it. Then the trip was postponed and a bunch of people had to drop out. Suddenly, I was getting frantic emails "Are you permitted to drive the geology vehicles?". Indeed I had been preparing for this moment for a long time. I was on the hook.

We packed up and headed out by 2pm on Friday. The 210 was slow until we got off at the 15, and shortly thereafter took old route 66 to an exposure of the San Andreas fault. It last ruptured in 1857, and is the next chunk of the fault 'due' to rupture. That'll be exciting when it happens. Back into the car and forward-ho to Barstow, which I changed lanes before continuing to Baker. At Baker we watered the horses, which, being Ford Expedition ELs, were rather thirsty. I gave my presentation on the history of the Garlock fault, despite being nowhere near it at the time. It forms the southern boundary of the Sierra range and the Sierra microplate, and is but the latest instance of a much older weakness in the crust, derived from the flat-slab subduction of the Shatsky conjugate. With all that out of the way we headed to The Mad Greek for a memorable gyro dinner, then pressed on north towards Death Valley.

The road wound through successive rift basins and eventually approached the town of Shoshone, where we parked for the evening. We avoided the rattle-snakes and headed for the pool. Here M and I worked out how to do various flips into the pool, while everyone else chilled in the shallow end. The sun set and I set out my sleeping bag in the grass. The day was still hot, but I thought better of getting cold at 4am. As night fell the stars popped out. Despite ambient light pollution from Vegas and the campsite they were still pretty good.

I woke up the next morning before dawn and the day was lovely. By the time we packed the sun was over the hills and the temperature was steadily rising. We paused in the area for coffee and to check out some old underground houses and fossilised elephant tracks. I snaffled some wifi for one last round of emails, and we were off! 

First up was the Confidence Hills just after entering Death Valley. Pushed up by a transform fault in the center of the valley, and just to the north was a mesa with paleo-shorelines, marking the altitude of the former lake. On the other side of the valley was a series of old sediments predating the initiation of subduction on the west coast of North America, and outrageously faulted hills. On the same transform fault just down the valley was a small cinder-cone volcano. Fault movement had split it in half, now separated by about 600m. Assuming slip rates stay constant, that implies an eruption about a hundred thousand years ago. Study of various paleo shorelines show that the valley has continued to deepen and to deepen rapidly.

The next stop was at Badwater, the lowest place in North America, at 86m below sea level. In the middle of a salt pan was a small brine lake. We stopped in the shade to talk about it, but even then the temperate was about 118F or 46C. Later in the summer, the Badwater ultramarathon begins here and stretches 135 miles across three valleys to Mt Whitney. Apparently they have to run on the white lines or else their shoes melt.

The next stop was Devil's golf course, a region of peculiar salt-created shapes forming insanely rough cobbles. Not far away was Mars Hill, a small hill covered in basalt cobbles worn angular by the wind. The site was selected as an analogue to the Vastitas Borealis on Mars, to enable comparative studies during the Viking missions. The rocks had all sorts of cool wind-created features, called ventifacts.

Zabriskie wash emerges from the Amargosa range. In the 1950s, road building accidentally diverted another wash into it, greatly increasing the flow. Now, during big storms, chunks of road (known in the trade as 'urbanite' or 'anthropocite', a conglomerate with a bituminous, organics-based matrix) get washed down.

Next up was lunch at Furnace Creek, an oasis and former Borax mining center. Here the temperature had dropped a few degrees, but it was still too hot for the trucks AC to have any meaningful effect. Not far away was the preserved remains of a failed Borax mining venture, complete with some crumbling walls and an iron boiler. The desolation was perfect. S and I speculated about the similarities and differences working here or on Mars. Mars is colder and the air isn't breathable, but otherwise it was pretty similar. At some point we vied with a coyote for room to examine the effect of salt leeching on boulder destruction.

The next stop was salt creek. When the climate changed here at the end of the last glaciation, most of the plants and animals died off. A few, however, managed to survive, some in increasingly isolated populations. One such creature is the pup fish. Now existing in perhaps 2 dozen different locations, these hardy fish are about the size of my pinky and live in the dried up hollows of the former lake system. One population of about 50 lives on a narrow rock shelf in a sinkhole in Nevada. 

The heat made the stops short, and as a result the trip was proceeding ahead of schedule. Next, we stopped at some sand dunes, where one person asked an interesting question. Sand grains are tiny, and their interactions with wind and each other are turbulent, scale independent, and non-linear. Why then, do sand-dunes form with regular sizes. It turns out there's a body of scholarship on the matter and it's possible to derive a dispersion relation that demonstrates certain wavelengths are preferable. J shared an anecdote about a sand dune expert who ended up fighting the Nazis in North Africa. Because he understood the sand dune dynamics, his platoon was able to conduct daring raids of various outposts, blow up the ammo dump, and then scoot off into the desert. Of course, the enemy gave pursuit, but would invariably get stuck in the sand and he would make his escape.

By now we were approaching the northern end of Death Valley. We stopped off at the Ubehebe crater, formed by a series of phreatic eruptions. With a co-conspirator I took advantage of the wind and slightly lower temperature to run through the outer craters and get a sense of the scale of the system. I was unable to find out, however, if there was a water table present in the floor of the crater. In other respects, it looked very similar to the crater in Vesuvius, only without the surrounding mountain.

From there, a few miles on bumpy dirt tracks took us to Racetrack playa. At about 40 miles an hour, the effects of the bumps are much reduced, but the ability to steer also diminishes... 

Racetrack playa is a dried up lake bed of absurd smoothness. About 4km long, the northern end is only 4cm higher. Funnily enough, it may be that tectonic actions tilt the bed faster than infrequent rain and flooding can level it again. We arrived at a campsite near an ancient mining venture and set out the deck chairs. The day had cooled off, and I went for a walk in the surrounding hills. Later that evening I found a few fluorescent rocks (possibly some fluorite) and a glowing green spider. I had never seen anything like it before. Its pedipalps were enlarged to the point of being legs, while its second pair of legs were tiny. In the meantime, S, Ge 136 TA of considerable legend, showed up and joined the evening's festivities. 

I set up my sleeping gear on top of the truck I was driving (so as to avoid wind-blown grit in the face), and with two able-bodied accomplices set off for an evening stroll to the playa. On the way I found a scorpion which glowed bright green under the UV light. The night was moonless and the stars were incredible. Less milky way than the southern hemisphere, perhaps, but certainly bright enough to see by. From the hill, the distance seemed to be about a mile. In reality it was closer to 2, but eventually we arrived on the unearthly surface and had a walk around. I brought some binoculars, with which the rings of Saturn were readily visible. Sadly, the other planets were still underground. There were plenty of meteors, satellites, nebulas, and so on to go around, however. At length we returned to the camp and, surprised to find everyone asleep, went to bed.

The next morning, I was confronted with a problem, how to get down from the trucks roof. In the end I opted for the simplest option; fall. Breakfast, packing up, and found another spider, this one less peculiar looking. My chocolate biscuits were still all melted from the day before. We got on the road and drove back down to the playa. In the light of day, we quickly found what we were looking for.

Racetrack playa is covered in rocks that have fallen from nearby hills. That, in itself, is not unusual. What is unusual is that these rocks move. Almost all of them have left tracks behind that reveal sliding across the surface, often in opposite directions, or with sharp changes in direction. This phenomenon has been studied, but since the rocks have never been observed while moving, it is not known for sure what happens. Spirits, transdimensional spaces, warp drives, energy vortexes, and so on can be safely ruled out. The general hypothesis is that during winter storms it gets a bit muddy and very windy and they get blown along. The idea that they get surrounded by rings of frozen ice seems to have been disproven. I threw my aerobie around, but the general setting was supremely unearthly.

We returned to the cars to find one had been appropriated by a grad student who wanted a sample of the local pluton contact. We squeezed into the remaining cars and headed off to find them. "Were you guys clever enough to take a radio" was, incredibly, greeted with an answer, and before long we had a visual. Two tiny specks crawling down a wash, dwarfed beneath the hills and cliff that towered overhead. One of them showed me a metamorphic rock excitedly. It bears mentioning that the geochemistry of metamorphism is still not at all well understood.

From here we bore west on rather bumpy (but still surprisingly good roads) past ghost towns and through a series of progressively wetter valleys. One was ringed with incredible wavey rock strata. One was filled with Joshua trees. Eventually we stopped at an outcropping of the Hunter mountain pluton - a rather large igneous intrusion and one of (if not) the first intrusions related to the beginning of subduction off the continental margin during the Jurassic. J found an impressive looking xenolith, or rock that got stuck in the middle of the plume from somewhere else.

We paused for lunch at the head of the Panamint valley, with a long view beneath a cloud of haze. We crossed the basalt flows of the Darwin plateau and joined the Owens valley just near Owen's (former) lake. The Owens valley was the last of the series to dry out. Prior to LA stealing all the water, it still had lakes, agriculture, and wildlife. We zoomed south. As we crossed the Garlock fault near Red Rock Canyon at the top of the Mojave, it became apparent that the haze was smoke from a few wildfires near La Crescenta. It was pretty surreal, as the desert vanished into white nothingness.

Soon we had fueled up and shooting south, crossed the San Andreas fault once more and entered the LA basin. I played hopscotch with a few semi-trailers on the ramp connecting the 5 and the 210. Fortunately I was able to sneak through a gap and up onto the ramp with only minimal squealing of tires and the bobbing of snoozing heads in the back. Once my heart rate returned to normal I set the cruise control to 0.01% below the speed limit and before long we were back in Pasadena. We had arrived at 4pm - one of the earliest field trip arrivals I've ever seen!

Post Script:

The following day (Monday), a few friends and I climbed Echo mountain, as one of our number was soon to be leaving forever. Since moving about 6 months ago I hadn't done the walk, and I found I was slightly unaccustomed to insanely long walks, despite my generally greater fitness. No matter, we proceeded upwards. About half way up the trail we entered a cloud layer. On the moonless night it became seriously dark. I usually walk without a flashlight/torch to enjoy the use of my other senses, but at times even my existing tricks weren't much use! Toward the top of the trail we popped out above the clouds and were rewarded with one of the best skies I've ever seen near LA. The milky way was visible! We milled around taking photos and screaming at the echo mountain. One of us managed to get 14 echoes! Soon two of the girls who hadn't brought a warm top got cold and began to giggle hysterically. We began the walk/stumble down through the darkness. I was tempted at times to crack out my flashlight and take longer steps, but at length we all made it down safely. Then it was just another 5 miles of trooping down Lake Street before getting back to the office some time after 3am. Some photos are also in the death valley album.