Monday, November 11, 2019

The Last Planetary Transit I'm Ever Likely to See: Mercury Today

The Sun shown just a bit less brightly today, not that anyone could tell. The planet Mercury passed across the disk of the Sun over the space of a few hours this morning, presumably blocking a bit of sunlight from reaching Earth. It was probably the last time I'll ever see a planetary transit.
Today's transit of Mercury (it is just above the center of the Sun's disk).
One needed some special equipment to see the event, mainly a camera or telescope with enough magnification to see the planet, and filters powerful enough to keep the observer from burning out his/her retinas. Luckily, I was able to locate the camera filter I used to observe the solar eclipse in 2017, and my camera has a 60x zoom. In the picture above, Mercury is just above the center of the Sun's disk. When I looked again about 45 minutes later, the planet had clearly moved to the right across the Solar disk (below).
Today's transit of Mercury (it is in the upper right hand quadrant of the picture).
I've seen three transits in my life, today's, Mercury in 2016, and Venus in 2012 (below). The next transit of Mercury is in 2049, when I'll be 92 years old. I may or may not be paying attention then. The next transit of Venus will take place in 2117. I don't expect to be around for that one at all. I wondered whether there would ever be a simultaneous transit of both Mercury and Venus, and it turns out that one will take place on July 26, 69,163 AD. I think I'll let that one pass...
Transit of Venus in 2012

Mercury is the smallest of our "regular" planets, and is even smaller than it appears in the photographs because it is around thirty million miles closer to us than the sun. It's actually not all that much bigger than our own Moon. The planet has been a bit of a stranger for most of time because it is hard to see in the dusk or twilight, and we've only had two space probes come close. Luckily, one of the probes has been orbiting for the last several years, so we have a treasure store of data on the planet. It was the subject of one of my very first blog posts back in 2008.

Saturday, November 9, 2019

Travels in Cascadia: Acrophobia, Glacierlets, and "Summer" in Whistler, B.C.

Inuksuk near the top of Whistler Mountain. See the note at the end of the post.
Acrophobia, the fear of heights, is an interesting phenomenon. I don't have it, I swear. I have no trouble standing on cliff edges, or climbing up in trees, or flying. Gondolas don't bother me. There are variations and subcategories though. I can stand on a high cliff and look over the edge, but I cannot abide watching someone else do it, especially my students. And I really don't like dangling.

There are lots of creepy heebie-jeebie moments in movies, like "Here's Johnny!", or "the call is coming from inside the house", but none gives me heart palpitations like the opening scene of "Cliffhanger" when Sylvester Stallone is trying to save a young women dangling from a rope over a vast chasm. She falls unfortunately, and I always drop the popcorn while covering my eyes. And then there is that first scene from "Vertical Limit", when not one, but three people fell down the cliff.

In my youth (roughly the ages 12 through 60 years) I was a regular peak bagger and rock clamberer. But I couldn't handle dangling from a rope. I only feel comfortable with solid rock or flooring under my feet. I rappelled down a cliff just once, I've never parachuted or gone hang-gliding, and rides at amusement parks that mimic the experience have never held any appeal for me.

This fact that I hate dangling is the background to today's description of our exploration of British Columbia that we undertook last summer in July. It's because I had to dangle over a cliff in order to see something I really wanted to see: a glacier from above.
Whistler Mountain from the Roundhouse Lodge at the top of the Whistler Gondola.
We were well into our trip by the time we reached the town of Whistler, BC. We had explored the Olympic Peninsula, parts of Vancouver Island, crossed the Strait of Georgia, and wandered for days in Howe Sound, the southernmost fjord on the west coast of North America. We drove there on a modern highway, much of which was stapled onto cliffs of Howe Sound. Before the highway was completed (in the 1960s) and improved and widened in the early 2000s (in preparation for the Winter Olympics of 2010), Whistler was an isolated logging community. Today it is a busy recreational center, winter and summer.

On the day we arrived in town it was a little hard to tell which season it was...it was July and it was cold and rainy. It could hardly be anything different (under the rules of Murphy's Law) since our weather thus far had been rather nice, and I was looking forward to seeing the spectacular alpine scenery around Whistler (my previous two visits had been in poor weather as well). We had scheduled only a few activities in the morning so the students could do some exploring on their own during the long afternoon.
The Peak Express ski lift leading to the summit of Whistler Mountain
As a major winter recreation site, the mountainsides are draped with all manner of gondolas and ski lifts, as well as some incredibly long ziplines. A single ticket provided access to most of the gondolas and the ski lifts that were running in the summer, so I headed up the Whistler Gondola, with the intention of riding and walking over a glacier for the first time (I've been to Athabasca Glacier, but not over it). There was also something up there called the Cloudraker Skybridge and the Raven's Eye that sounded worth checking out.

So this is where we talk about acrophobia. I had no problem with the gondola ride at all. It's in an enclosed space with seats and a floor and all that. But when I got out at the Roundhouse Lodge at 6,069 feet, I found that I was still 1,100 feet below the summit of Whistler Mountain. And I would have to get their via...a ski lift. A spindly rickety dangling ski lift. I know all you skiers out there are used to these things, but I'm not. I don't like them. But it was the only way to get to the top of Whistler Mountain within our time constraints, so I hiked over to the base of the cliff and loaded myself onto the lift.
The Cloudraker Skybridge and Raven's Eye (on the far right). The "snow" is actually the top of a glacier.
There are a few places I've been that feel like no human should really be there. At the very bottom of a huge open-pit mine, for instance. One looks at the rocks exposed for the first time in millions or billions of years, and it just doesn't feel comfortable. Standing two feet from flowing lava. And dangling from a thin cable over a cliff of crumbling rock. It just didn't feel right. But there I was, and soon I reached the top no worse for the wear.
Walking out onto the Cloudraker Skybridge. The Raven's Eye is in the distance, upper left.

Once I was on solid ground again I felt better. I walked over to the Skybridge and crossed it several times. It didn't bother me one bit, and I had a great view down the small glacier beneath my feet. Glacier is perhaps a strong word for what this icefield was. A glacier is defined mainly as a mass of ice large enough to flow under the influence of gravity, and this one qualified, but I suspect the rate of movement is on the order of a few inches or feet per year. The term glacierlet is sometimes applied to these ice fields (most Sierra Nevada glaciers are of about this magnitude in size).
It was immediately clear that this glacier was only a shadow of its former self. On the slope far below I could make out a barren ridge surrounding a turquoise lakelet with a couple of huge boulders. This was a very young terminal moraine, so young that plants had not had a chance to grow. The glacier ended down there only a hundred or so years ago. Although there is snow in the lower reaches, the actual glacier ends today hundreds of feet above the lake.
Terminal moraine and moraine lake at the former end of the glacier at Whistler Mountain.

The true size of the glacier today can be seen in a satellite image taken in the late summer when nearly all of the snow (but not glacial ice) has melted away (below). The loss of glacial ice is a worldwide phenomena indicating that the global climate is warming. When these glaciers disappear, their loss will have serious ramifications for the regional ecosystem. The glaciers serve as a dependable year-round water source for alpine creeks, and when that disappears, so will the animals and plants that are dependent on that water. They don't have anywhere else to retreat to.
Meanwhile, I had one more challenge. As physics tells us, what goes up must come down, and I had been procrastinating, walking around the nature trails around the peak of Whistler Mountain. I was out of time, and was going to have to take the ski lift back down. I'm glad no one was with me, because I was whimpering "oh, sh*t" over and over as the ski lift chair tipped over the edge of the void.
The arete on the east side of the glacier. The ski lift went right over it.
The scenery gave me something else to concentrate on, so I snapped lots and lots of mostly useless pictures, but I did get a decent perspective on the terminal moraine and small moraine lake behind it. The turquoise color is caused by clay-sized particles suspended in the water, derived from the grinding action of the glacier on the rocks at its base. An arete is a sharp jagged ridge that divides glacial valleys. The ski lift carried me right over the top of it.

You'll all be happy to know that I gathered myself together and was not whimpering by the time I reached the bottom of the lift.
In the end, the lousy weather mostly kept me from seeing the spectacular alpine scenery that surrounds Whistler. On the other hand I was able to see a glacier up close, and learned to live with my subtle form of acrophobia.
Google Earth image of the small glacier at Whistler Mountain. The cirque is the bowl-shaped valley where the glacier originates. The skybridge traverses the upper end of the cirque.
The Inuksuk at the beginning of the post was the icon of the 2010 Winter Olympics that were held in Vancouver and Whistler. The stone men have been a part of Inuit and other Arctic cultures for thousands of years. The use of the Inuksuk at the winter games was somewhat controversial, as no Inuits ever lived within hundreds of miles of the site of the games. The local First Nations people were the Squamish and Lil'wat.

Whistler refers to the Hoary Marmots found in the region. I saw one of them at the Roundhouse Lodge when I got back from the mountain.


Sunday, November 3, 2019

A Bit of "Where's Waldo the River Otter?" at the San Luis National Wildlife Refuge

There are things in my life that are more thrilling than spotting River Otters (Lontra Canadensis), but there are not many of them. I spend a lot of time on the Tuolumne River where it flows through my town, and also at the local national wildlife refuges, including the Merced, the San Luis, and the San Joaquin. I'm usually searching for birds, but a bit of my attention is always watching for rarely seen mammals like beavers, foxes, and especially River Otters.
We were on the eastern leg of the San Luis NWR Waterfowl Auto-Tour when I spotted what I thought were four ducks bunched together. But they didn't look right, and after a moment I realized that it was a family of River Otters playing on the banks of the irrigation canal. We played a brief game of hide and seek (I mostly hid behind the car), and they eventually swam away downstream (down-canal?).

Most of the time I forget that I have a fully functional video with my camera, but I thought of video first this time around and got a short shot of the family swimming away together. Then I snapped pictures as I could in the dim shadows where they were hiding. What I noticed later is that in each picture of an individual, there was actually a second otter photo-bombing the shot. Can you find the extra otter in each picture?

River Otters in California took a real beating over the centuries of European occupation in California, with trapping and destruction of their habitat by gold mining, damming, and urbanization causing a drastic drop in their population and range. With efforts at reclaiming the river environments in the Bay Area and Central Valley, they have begun to spread out again. A pair of otters was even seen in Yosemite Valley a year or two ago.

I've seen otters on a number of occasions on the Tuolumne River, but this was my first sighting at the San Luis refuge, which is part of the San Joaquin River drainage. The river had been decimated by reservoir construction decades ago and the river was dry for many tens of miles in the San Joaquin Valley, but recent agreements have resulted in a new river, with the potential of even the return of the salmon. The otters will surely follow!

Thursday, October 24, 2019

Travels in Cascadia: Howe Sound and the Challenge of Living (and Mining) in Vertical Places, Part 2

Howe Sound, the southernmost glacial fjord in western North America, is a fascinating place to explore. We've already looked at the journey by ferry that we used to get there, we've looked at one of the toughest hikes I've ever taken for a bird's eye view of the sound, and a look at some of the engineering required to live in a vertical place.
Today's post is about resource extraction. That mountains have formed here at Howe Sound suggests that huge forces have acted in the interior of the Earth, and the tectonic activity is very often accompanied by mineralization. The rocks here include ancient marine sediments and volcanic rocks that have since been metamorphosed. Hydrothermal activity leached out metallic ores over a wide region and concentrated them in spring deposits on the ocean floor. The ores included iron, zinc, gold, silver, and arsenic, but most of all, they included copper. The ores were discovered in 1888, but it was sixteen years before the ores could be mined and processed because of the remoteness of the region and the difficult terrain. In 1904, the Britannia Mine began production, ultimately becoming the biggest copper mine in the British Empire.
There were extraordinary challenges in developing the mines, not the least of which was the steep terrain, and the lack of access. Landslides and flash floods were constant hazards, and two events were notable: in 1915 a slide demolished one of the mine camps, killing 56 people, and in 1921 a flash flood killed 37 individuals. The mines themselves were dangerous (as they always are) with 98 fatal accidents over the 70 year history of the mine.
The mine was certainly productive, however. During the 70 years the mines operated, ore totals included 650,000 tons of copper, 137,000 tons of zinc, 17,000 tons of lead, 500 tons of cadmium, 188 tons of silver, and 15.6 tons of gold. The gold alone would be worth $750 million at current prices. My rough calculation of the price of the copper the mine produced is $3.4 billion.
The closure of the mine in 1974 was devastating to the local community. Not only were the jobs suddenly gone, but the 130 miles of underground tunnels exposed sulfide minerals to the atmosphere, and acidic waters laced with heavy metals were draining down the hillsides and into the otherwise pristine waters of Howe Sound. The mine was one of the worst point sources of pollution in all of Canada. Mitigation efforts have been ongoing for years, with water being treated to remove the metals, leaving a toxic sludge that is put back into the old mine tunnels.
The community that remained faced the future of many mining boom towns: loss of population, despoiled water and massive scarring of the landscape from mining activity. Instead of dying away, the community hit on the idea of creating a museum out the remnants of the mining complex. One of the biggest problems was the concentration mill, the 20-story-tall factory just above the coast, and visible from the highway (see the first picture in this post). It was dilapidated and falling apart, but funds were secured to replace the windows and the siding in the early 2000s. With the arrival of the Winter Olympics in 2010, much of the museum complex was in place.
Our tour was well-done. They recommissioned an ore delivery tunnel near the concentration mill to serve as a model of the underground workings that are actually found mostly in the mountainsides upstream. The drilling equipment was reconditioned into working order, along with the mucking machinery. The drilling demonstration was LOUD (we were warned specifically to cover our ears), but it really brought home the kinds of conditions the miners had to work in. I have little doubt that many of them had serious hearing problems later in life. I don't know what Canada's version of OSHA is called, but they would never allow the miners to work without ear protection today.

They also demonstrated the carbide lamps that were used for lighting in the mines for many decades (above). Better than candles, certainly, but I would want some bright flashlights, and a bunch of them. Being lost in a totally dark mine (or cavern) is one of my serious phobias.
I deeply appreciated one aspect of the tour that most people might not...they preserved untouched one of the core shacks from the mine. I've seen only a few of these, and the ones I've seen were much smaller. One might wonder how the miners knew which direction to build their tunnels to reach the richest ores. They drilled thousands of cores into the mountain to sample the rocks so they could map out the ore bodies. The core shack preserved tens of thousands of these cores.
The interpretive signs even helped a bit in allowing students and tourists to look for the desired minerals in the cores (below).
The last part of the tour was apparently debuted not long ago. They used a multimedia presentation showing how the ores were treated in the concentration mill. "Presentation" sounds kind of droll and boring, but it wasn't. There was some surprising humor, for one. I won't spoil all the surprises, but one incredible bit was how they played the sounds of the mill at the volume it would have been in real life. I was struck once again about how the miners would have suffered hearing loss whether they were employed underground or working in the concentration mill.
The concentration mill is big from the outside, but it actually felt even more immense from the inside. The effort that it took to separate the metal from the mineral ores is astounding. One comes away with an appreciation for the many ways that technology has made our collective lives easier. And it will make it harder for me to ever throw away a recyclable metal object.

They allowed us to wander a little bit around the ground floor of the mill, and I was able to pick out something sort of unique. In the wet environment, copper carbonate stalactites have formed on some of the girders!

All in all, a great experience. If you are ever in Howe Sound, consider the tour at the Britannia Mine. Information can be found at https://www.britanniaminemuseum.ca/.

Tuesday, October 15, 2019

Its Really Been That Long? 30th Anniversary of the Loma Prieta Earthquake on Thursday

It's Earth Science Week, and "Geoscience is for Everyone" is the theme for this year. Geoscience IS for everyone, because geology dominates the lives of everyone. No one can escape it, for better or worse. Better, when we find inspiration in the awesome forces that have made our planet, and worse for the geologic hazards that exist everywhere on the planet in one form or another. Here in California, one of the premier hazards are the earthquakes that occur here with disturbing irregularity (it would be so much nicer if they followed schedules so we could prepare). I'm writing about the anniversary of the Loma Prieta earthquake a few days early, but we had two moderate earthquakes in less than 24 hours in Northern California (magnitude 4.5 and 4.7), so seismic things are on my mind.
No photo description available.
Two good-sized earthquakes as recorded at Modesto Junior College
We can only share our stories to keep that knowledge at the forefront that will allow us to survive and recover from the major earthquakes to come. Here's my story from 1989, when my teaching career was just beginning.
No, this isn't what happens (credit: A. June)
On October 17th, 1989 at 5:04 PM, my physical geology laboratory had just finished and almost everyone had gone home to watch the World Series. A couple of students were helping me (it was Maureen and Sonny; funny how I remember the names of the first students I had better than the ones I had last semester). We were 100 kilometers from the epicenter, so when the seismic waves started to shake our building, the movement was a strong rolling motion instead of sharp vibrations. We looked at swaying TV monitors, and commented that it was an earthquake. It was a most scholarly discussion, actually. We realized the shaking was not stopping, and we thought we could sense the direction of the quake as well. We started to guess where it might be happening, but when the shaking reached the 40 second mark (the energy was spreading out, it lasted only 10 seconds or so near the epicenter), we realized it was a major event, and that fatalities were probably occurring (and unfortunately we were right). The deodar trees out the window were whipping back and forth as if they were in a high wind. The strangest part for me was the unconscious decision I was making as the shaking progressed. Despite having a quiet scholarly discussion, my body was moving from the front of the podium to the back, where there was a nice solid space to hide under. I would have dived under if the quake had lasted any longer.
Well, this can happen, but most people survive, even in the worst of quakes (credit: A. June)
In hindsight, I should have been a bit more aggressive about taking shelter under the desk. An analysis of our building a year or two later revealed an architectural weakness that suggested the building could collapse if the seismic waves hit it from a particular direction. A seismic retrofit a decade later included some massive shear walls in the lab I taught in.

Meanwhile, at the city library, my children were making me proud. At the time of the quake, there were huge sailing ship models on display, in some cases right on top of the book stacks. The stacks were not reinforced or braced, so there was a real potential for injuries if the quake was strong enough to knock those stacks over. I was told that most people were just standing there watching the bookstacks swaying, but my kids, my well-trained and intelligent kids were the only people in the room to take shelter under the sturdy study tables. Luckily, as I said before, we were on the fringes of the effects of the earthquake and no one was hurt.
The double-decker freeway in Oakland. It was not designed for the amount of shaking that occurred.

The Loma Prieta earthquake, a magnitude 6.9 event at a depth of 11 miles, was a tragedy: 63 people died, and 3,700 were injured. If the World Series game between the A's and the Giants hadn't been about to start, the death toll would have been much higher. Traffic was stunningly light that afternoon. Despite this, the Bay Area was in chaos for days, and months passed before life got back to normal. We were on the fringes, so instead of pain and suffering, we had a profound learning experience that was remembered by my students for the next decade and a half. But it has been 30 years now, and many of my students weren't born when the quake happened. Few of them have felt a quake at all. The large quakes like Loma Prieta and Northridge are ancient history, and there is less of that innate knowledge of what they should do when one hits. Few admit to having any kind of emergency kits at home, and they have no plan for what to do when the next big one hits.

Fault studies across California make it clear that more big tremors are coming, almost surely within the next decade or two. We educators must keep these past events alive in the minds of our students so they will be ready for these events when they come.

This is an abridged version of a blogpost from 2009.

Monday, October 14, 2019

Travels in Cascadia: The Toughest Hike I'll Ever Do...Stawamus Chief in British Columbia

Note that I didn't say the toughest hike YOU will ever do. Every hiking experience is individual, and this one left me...breathless. Stawamus Chief is one of the most popular hikes in the Vancouver-Squamish region of British Columbia, and when we passed through the area last July, I knew I needed to give it a shot.

Stawamus Chief is a granite dome that rises more than 2,000 feet above the east end of Howe Sound, the southernmost fjord on the west coast of North America. The dome actually has three summits, the 1st, 2nd, and 3rd, and the trail climbs to the first summit in a little over a mile. That doesn't sound so bad, does it?
The beginning of the trail is pleasingly flat, rising gently through the Stawamus Chief Campground. The wide flat trail offered no clue about what would follow. I know it sounds dramatic, but from the moment one takes the first step upward as the trail starts the climb in earnest, the trail is relentless and steep.
Some of the steps are on wood stairwells, but the rest of them are large uneven stone blocks that I found challenging. And there are no breaks. Many trails are steep, but most all of them have short breaks were the trail is level for a few steps. Not this one. It never stops climbing.
I climbed higher and higher, and grew more exhausted with each step. The thought was slowly building in my head that I was no longer young, and that some trails were simply too tough for overweight 60-somethings. But then another thought immediately followed: this quite probably was the only chance I would ever have at making the summit. Who could know if I would ever be here again, and with time marching on, my ability to climb would no doubt degrade with age. It was probably the toughest hike I would ever do (in the future sense). I decided I had to do it, and kept going. And going.
Everyone's experience will differ, of course, and some younger and healthier people would not have that much of a problem on this trail. Part of my own worries weren't so much the climb, but the descent. All of those huge steps had to be repeated, but going down, and I worried about the impact on my knees and ankles. But I had already come so far.
Stawamus Chief is a granite dome, and the resemblance to Half Dome in Yosemite Valley is unmistakable. One of the things about Half Dome is that it was never covered with glacial ice. The dome took it's iconic shape from exfoliation of the outer slabs of granite. The corners and edges snapped off as the pressure of burial was released upon exposure to the surface. Glaciers at the base quarried away the fallen rocks.

Stawamus Chief was different: as I approached the summit, a most unusual rock emerged from the trees. It was a boulder perched on a granite platform. It was a classic example of a glacial erratic, a rock left behind as the glaciers that flowed over this surface melted away. Unlike Half Dome, the summit of the Chief had been covered by glacial ice. And not just a little...the ice here was over a mile thick!
In the end, I didn't make the true summit. The young men in our group reported that another twenty minutes and 200 feet of hard climbing remained ahead. I just wasn't up to it. But I did make it to the summit ridge, which provided a stunning view of the eastern end of Howe Sound. From this elevation, the glacial origin of the fjord was obvious. And I was happy to be where I was. Elated, even. And thrilled to be alive (literally!).
The knees and ankles took the expected pounding on the way down, but no lasting damage was done. I would live another day, and take on the next challenge. It could well have been the toughest hike that I would ever do (in the future sense; I've done some really tough hikes over the years), but the neat thing about life is that you never know what comes next. Maybe I won't do this trail again, but there are many other trails and challenges ahead. Again, that sounds dramatic, but finding one's limits is always an exercise in drama.

Saturday, October 5, 2019

Travels in Cascadia: Howe Sound and the Challenge of Living in Vertical Places, Part 1

We didn't fly over it, so I've clearly needed to borrow this image from Google Earth.

We have (slowly) been reviewing our geological exploration of British Columbia back in July, and when I last posted we had reached Howe Sound, the southernmost fjord on the west coast of North America. We arrived by ferry at Horseshoe Bay (from Vancouver Island), and then spent two days exploring the museums and parks of the city of Vancouver. But now we were headed into the interior, and needed to follow Highway 99 along the south side of Howe Sound.

Howe Sound is, as noted earlier, the southernmost fjord in western North America. A fjord is a glacially carved bay, and as such has nearly vertical rock walls sloping down to the waters of the bay. This kind of topography entails serious engineering difficulties for anyone who wants to live in, travel through, or mine in the fjord. Prior to the 1960s, the only form of transportation to the inlet of the bay at Squamish was by water. A railroad was completed between Squamish and Vancouver in 1956 (after a delay of something like 40 years), and the first iteration of Highway 99 was carved out of the walls of the sound between 1958 and 1969. When Vancouver was selected as the site of the 2010 Winter Olympics, the highway was widened to four lanes to provide access to Olympic venues in the Whistler area.

The development of transportation corridors led to the development of a few small towns and villages along the route. And that caused problems in this steep countryside. We stopped in the little village of Lions Bay to have a look at a perilous situation.
The dangers of the steep mountain slopes are clear. In 1915 and 1921 a short distance to the east at the Britannia Mine and Britannia Beach, mudflows killed nearly a hundred people. The community at Lions Bay faced the same danger, and in 1981 a debris flow took out highway bridges, leading to several fatal accidents. In 1983, boulders and mud roared down Harvey Creek, destroying a number of buildings and killing two people.
Thus it was that we were looking at a strangely shaped Harvey Creek as it appears today. The channel is lined with boulders, but they are cemented in place. Upstream, a dam is visible, but the dam has holes at the base, and is not capable of holding back water. It's not designed to store water at all, but to stop the forward movement of debris flows coming down Harvey Creek.
In our next post, we'll have a look at the Britannia Mine, the largest (and perhaps steepest) copper mine in western Canada.

For more details about the geology of the Sea to Sky Highway and the engineering challenges, check out: http://quimpergeology.org/wp-content/uploads/2018/03/Sea2Skytour.pdf