As noted earlier, I had the good fortune to spend last week in Yosemite National Park, celebrating the wedding of my friends Jason and Lindsay, and in general poking around in one of the coolest places around. Below, a summary of the three-day trip:

Friday:
Lily and I flew to Modesto, California, and rented a car. It took about two hours to drive up to Evergreen Lodge, where we checked in and then headed out for a short hike in the Hetch Hetchy area. Hetch Hetchy was dubbed "Yosemite's sister valley" by John Muir in an attempt to keep it from being dammed. But the city of San Francisco had been destroyed in 1906 by earthquake-induced fire, and the call for a reliable water source was an important force in overpowering Muir's conservationist ideals. Ken Burns apparently explores this saga, the first instance of "development vs. conservation," in the second episode of his new National Parks series. (I saw the first episode, but haven't caught up on the rest of it yet.) The valley was dammed in the 1920's, creating the Hetch Hetchy Reservoir:


Here's the O'Shaughnessy Dam, named after the chief engineer of the project:


I didn't find it as spectacular as Yosemite, but it was sure a pretty place. Walking along the north side of the reservoir, I reaquanited myself with some fine Sierran granites and granodiorites. Here's a sweet little xenolith (or maybe an MME; how can you tell an MME from a mafic xenolith?):

Back to the Evergreen for the rehearsal dinner (Oktoberfest theme!) and then bed.

Saturday:
Up early, got some coffee, drove an hour to reach the Yosemite Valley. I liked how quiet things were compared to the throbbing pulse of summer. This view of El Capitan, for instance, is typically mobbed with tourists. This day, we had it to ourselves for five minutes or so, then shared it with one other car:


Time to stretch the legs! We decided to hike up to Vernal Falls. On our way up, the base of the falls was still in shadow, with low-angle morning sunlight dramatically illuminating the upper reaches of the falls:


Looking back down the valley we had climbed up... I like the dark shadow of the cliff merging with the dark shadows of the trees below:


But if we set the camera's F-stop a bit differently, we can see what's going on in all that shadow. There's the trail we climbed up, with fellow hikers for scale:


Up top, photographing the waterfall:


On our way back down, with more of the falls illuminated as the sun rises in the sky:


Looking north across the valley from where we parked our car, marvelling at the huge exfoliation joints there: rounding these exposed plutons into granite 'domes.'


... or Half Domes, as the case may be:


A view from further out, again with Half Dome the most striking landform:


Then, we headed back to clean up before the wedding. Great ceremony, amazing meal. Drinks, dancing, rhubarb jam, bluegrass, reminiscing with old friends and new. Ahhh.

Sunday:
Breakfast and coffee with the wedding party, then off to check out some big trees. We drove to the Tuolumne Grove of giant sequoias. It started snowing on the way there, but we didn't let that deter us. On the hike down from the parking area (where, by the way, they had closed the Tioga Road), we found this nice example of spheroidal weathering in an outcrop of granite:


But the real attraction was the enormous sequoia trees. Here's one:


And a dead one, with a car-sized hole cut through it:


I found these trees very impressive: they were just stunning in their grandeur and immense age. Snow continued to fall as we left. We had to get going to make our flight home. Somewhere on the way down the mountain, Garry Hayes and his wife passed us going up the mountain. Ships passing in the night -- sorry I missed you, Garry! We made a couple of roadside outcrop stops, then got back to Modesto and traded in the car for an airplane. Our "redeye" route back to DC took us through San Francisco and Los Angeles, and I ran into Thomas Friedman in the airport. Got back to BWI at 6am, and headed off to work...

Labels: california, glacial landforms, national parks, plants, travel, tv, water resources, xenoliths

In a few days, the world will get what it's been waiting for. In a few short days, an eagerly-anticipated event will take place that will hopefully make the world a better place and bring satisfaction and closure to those who have waited for what seems like forever. I can hardly wait...

... I speak (of course) of the season premiere of LOST.

The Times profiles the dude who's in charge of keeping track of everything.
The Post examines the show's exploration of space-time in the context of earlier shows.
Entertainment Weekly has a quiz about some of the minutia in Season 4. (I got 29/34 right.)

Namaste!

Labels: humor, tv

Two of my favorite things to talk about, global warming and the Talking Heads, are combined in this trailer for a new program on PBS:

Hat tip to Babak R. for passing this on to me. I'm a day behind the curve in posting it (the show aired last night), but I'm a day behind in just about everything these days, so I'll post it anyhow.

Labels: climate change, global warming, music, tv

Over the past couple of weeks, I've watched a number of videos that readers of this blog may be interested in. Yesterday, I blogged about A Private Universe and Minds of Our Own. Let me mention a few others today.

The Life of Mammals is a BBC production by the great David Attenborough, who also made Life of Birds, Life in the Freezer, Trials of Life, etc. etc. etc. (Attenborough has been making nature documentaries for the BBC since the late Miocene.) If you're into geology as part of a larger natural system, or if you happen to be a mammal yourself, this is a series well worth watching. Attenborough has a signature style involving showing up in different corners of the Earth, and carrying on a continuous narration the whole time. One moment he's in Tasmania, the next in Brazil, but his thought process is uninterrupted. The discussion is of the highest quality, without being too technical. He's got a real gift for this business. Five stars.

I also watched Walking with Prehistoric Beasts, from the Discovery Channel. It's about past creatures; Cenozoic mammals and birds. Because the animals it describes are extinct, it can't have footage of the narrator (Kenneth Branagh) strolling amongst the entelodonts or Andrewsarchus. Instead, they've used puppets and lots of computer generated animation to depict their subject. They're pretty clever about this, using "film" techniques that give it the flavor or an actual nature documentary: They mimic night-vision footage, for instance, as well as "handheld" camera shakiness, herds fleeing an overhead "helicopter" perspective, and the subjects nosing up to the "camera lens." While the animals they describe are quite interesting, I found the production to be a bit on the bombastic side, with pounding music intended to raise the viewers' adrenaline levels during a hunt scene, and so on. All told, the content wasn't as good as Life of Mammals, but I appreciated the way they handled the production, so I'd give it 3.5 stars.

Labels: critters, fossils, mammals, movies, teaching, tv

I must recommend a couple of videos to any science educators out there. (I just watched the last of them last night.)

A Private Universe was an eye-opening half-hour video that was followed by a short series called Minds of Our Own. (Links go to video on demand from Annenberg Public Media.) Both titles follow a similar format, and pursue similar content. Their subject is the difficulty in getting students to learn science. Both videos make the hypothesis that the major obstacle in science education is not complexity, or abstract reasoning, but pre-existing ideas about the way the world works. Students come into our classrooms with certain notions, and unless we teachers (a) know what those notions are and (b) explicitly confront them, then the students' natural reaction is to stick with their perfectly-reasonable ideas about the way the world works (and reject the scientifically valid ideas about the way the world works).

A Private Universe opens with a scene of Harvard's graduation, and the filmmakers interview the gowned students about the phases of the moon. Full moon, half moon, new moon, half moon again... Why does the moon have phases. Everyone shown indicates they think that it's the shadow of the Earth on the moon that give it its phases. In Minds of Our Own, similarly shocking scenes unfold wherein the graduates of MIT can't use a battery and wire to light a lightbulb, and again where Harvard graduates are tested, this time on the subject of trees. A tiny seed grows into a massive tree: where does all that weight come from? All those interviewed thought the tree's mass came from the soil (as opposed to CO2 in the air). It's really something to see -- some of the brightest students in the country, demonstrating a basic scientific illiteracy.
Subsequent one-on-one interviews with elementary, middle, and high school students probe for deeper understanding of just what these students think is going on. Some of these interviews yield bizarre interpretations of reality so that the student can match their erroneous worldview with their well-developed logic and reasoning. It's quite striking to see the lengths they will stretch their minds to, in order to accomodate their pre-conceived notions. A Harvard education professor (Philip M. Sadler) who is interviewed in the films says "The most important thing we can do as teachers is find out what our students already think when they walk into the classroom" (paraphrase). You can be an extremely skilled intstructor, in other words, but this basic step is essential. If you don't assess your students' understanding before you teach them, you're setting them up for failure. Students must be confronted with their false views and shown why they are false, if they are to open their minds to other possibilities.

One of the most gratifying scenes is when a young man is explaining why pressure increases in a closed piston. At first, he thinks that because the volume is less when the piston is compressed, it must contain less air. But as he's illustrating this notion, and being asked clarifying questions from the interviewer, you can see him realize that the same number of air particles must be in the piston when it is both extended and compressed: they're just closer together when it's compressed!

From the perspective of an educator, the depressing side of this realization is that we have nowhere near the amount of time it would take to have one-on-one conversations with every student to explore their misperceptions and then gently lead them through a line of logical inquiry to correct those ideas. That takes some serious time. Is there a more efficient way to root out these ideas? I'm not sure.

Has anyone else seen these videos? I was very impressed. Now I'm wondering how best to incorporate this new perspective into my own teaching...

Thanks very much to Nicole LaDue (NSF) for sending a DVD of these videos my way.

Labels: astronomy, movies, plants, teaching, tv

Yesterday evening, I watched "How the Earth Was Made," a History Channel program available on DVD (Amazon, Netflix, NOVA library). It's an ideal video for introductory students, as it covers 4.5 billion years in 100 minutes of program. I think it's probably worth a viewing even for professional geologists, though there's definitely some stuff in there to take issue with. For instance: (1) they call stromatolites "organisms;" (2) they suggest that Snowball Earth occurred because the continents were clustered over the pole, not the equator, and (3) they show the Pleistocene North American ice cap stretching south into Georgia and the Carolinas. Still, I'm a fan of any video which can animate visually the processes that geologists imagine, and this show achieves that in spades. Have you seen it? Chime in below in the comments section.

Labels: movies, tv

Okay, so we've all heard what a stinker the new movie 10,000 B.C. is, right? I actually went to see it, on Geotimes' nickel, along with a couple of other scientists so we could assess the scientific validity of the film for the magazine. Afterwards, I went to enter my own "review" into Netflix (2 stars out of 5) and I noticed there was another "10,000 B.C." film in the Netflix library: "L.A. 10,000 B.C.," a program from the Discovery Channel that examined the natural history of the Los Angeles area during that same time. I decided to check it out, and last night I watched it.

My brief review: It's not really a traditional natural history program. Instead it takes fossil evidence and uses it as a starting point for a "reality T.V." style stunt program. They take three L.A. stunt actors and "train" them to be Ice Age hunter-gatherers. Then they build pneumatic robots to mimic the teratorn and Columbian mammoth, and the stuntmen and women have to battle them. No joke. This resulted in some cool visuals, though: the mammoth crushing a ten-pound can of tomatoes and having all that red spray everywhere (mimicking the head of a Clovis hunter). And the footage of the stuntman being tossed thirty feet through the air by the "angry" robot mammoth was kind of cool too.

But you can't really call that a nature program. There were some cool facts presented, but the majority of the film was devoted to sensationalism of the encounters between humans and these Pleistocene species. The film was also very repetitive, taking half an hour's worth of material and stringing it out into 1.5 hours. It appeared to have been designed so anyone channel-surfing could get an orientation as to what the program was all about regardless of when they tuned in. That's kind of lame if you're watching the whole thing from start to finish, methinks.

Labels: birdies, cenozoic, mammals, movies, tv

In an article in Newsweek, the hosts of NPR's "Car Talk" talk about the car of the future.

Turns out that the Tappet Brothers, one of whom doesn't even own a car (!), are lobbying Congress for increased automobile fuel efficiency. They're also starring in a new episode of the PBS series Nova. And they have some advice for you, the consumer: "Get a Prius."

FYI, since we're talking about it -- a quick update on my "Pious" seems in order. Its current fuel efficiency (running average since I bought the car in December) is:

Labels: action, climate change, global warming, oil, petroleum, prius, tech, tv

Just got through watching an episode of the PBS program NOVA (which I like to refer to as the "other" NOVA). The episode was titled "Volcano under the city," and it looks at the volcano Nyiragongo in Congo, central Africa. This was the same volcano that had such a spectacular eruption in 2002, when lava flowed through the city of Goma, on the shore of Lake Kivu. The program follows UN vulcanologist Jacques Durieux on a journey through Goma and into Nyiragongo to evaluate the risk for the ~2 million people who live in the mountain's shadow. The program explores volcanic hazards including lava flows, landslides, lake overturn (a la Lake Nyos), and pockets of CO2 in low-lying areas on land. This last one provided what I found to be the most dramatic footage: Durieux tosses a signal flare into one of the ditches, and the smoke rises and flows on top of the invisible layer of CO2 below: it demonstrates dramatically how there's something invisible pooled in that ditch due to its density. There's also plenty of footage of frothing spewing blobby lava, if that's your thing. As is often the case, the narrator overpitches the dangerous aspects of the situation, and the whole hour-long show feels kind of like a hyped-up movie trailer. Certainly the situation there is dangerous, but I feel like some credibility gets lost when every word is uttered with a sense of looming menace.

Labels: africa, CO2, movies, tv, volcano

Labels: canada, fossils, humor, tv

Saw this video yesterday on the "How Stuff Works" website. It shows a crazy number of mammoth fossils being unearthed in Siberia (due to thawing of the permafrost there). I was kind of astonished how casually the fossils were being treated: at one point, a Russian scientist takes two mammoth teeth and grinds them together with vegetation in between, to demonstrate how they chewed. This strikes me as kind of rough treatment for specimens like this.

Labels: fossils, global warming, tv

OK, if you watch LOST and haven't seen this week's episode yet, then go do something else. Honestly, what are you doing reading geology blogs anyhow?? There are more important things to be doing... Like catching up on LOST.


(Are you gone yet? DON'T KEEP READING. I warned you. Don't.)


For those of you who watch LOST, umm, wow. Thursday night was what the season opener should have been. Major new insights, major new questions. And: son of a gun, some of them have geological tie-ins. Who'd-a thunk it?


I mean, those of us who've made it through Season 2 know that the island has a weird magnetic anomaly, a feature which not only crashed Oceanic flight 815, but also apparently shields the island from outside observation. Geotimes even wrote a piece on this geological plotline. At the end of Season 2, a team of (apparently) polar scientists in the employ of Penny Widmore even remotely detect a magnetic pulse from the island.


Among the new insights from this week's episode: the location of a sunken Oceanic 815, complete with tail section and wedding-ring-less pilot Greg Grunberg. And not only is it discovered by robotic submersibles, but they show a map of a major subduction zone to show where they found the plane. (See below for a screen capture.) But is it really the real Ocean 815? Or a decoy? Regardless, when was the last time the Sunda Trench appeared in a fictional TV show?

Labels: fossils, plate tectonics, tv

First things first: colugos (pronounced cho-LOO-gos) are not "flying lemurs." Though they've been dubbed that, they are not lemurs, and they don't fly. They do glide, however, and that's what we're going to focus on today.

A few years ago, I visited the Malaysian state of Sarawak, on the island of Borneo. While there, I spent a couple of days in Bako National Park, a coastal forest park. Bako was great: bearded pigs, proboscis monkeys, pitcher plants: there was a bunch of cool, weird biodiversity there. One evening, while wandering back to my cabin, I saw some guys with spotlights roaming around in the forest. They were filming something up in the trees. These spotlights they were using were bright: it was professional gear. I asked who they were, and what they were looking at. Turns out they were from the BBC, filming an arboreal animal for footage to be included in a new program. This program was later watched by millions of people around the world: it was the groundbreaking series Planet Earth. The animal the Planet Earth team was pursuing in the forest was the Malayan colugo (Galeopterus variegatus).

Late last year, in Science, a study of a genetic marker shared by colugos and all primates established that the colugos were our order's closest living relatives, from which we diverged about 90 million years ago. They are fascinating creatures, even aside from this sense of kinship. I've seen colugos in two other places besides Borneo: Palau Tioman (off Peninsular Malaysia's east coast), and in Singapore (at the Zoo, but the colugos there are wild and uncaged). Each time, I've been astonished at how odd they look: clutching a tree they look like Gollum from The Hobbit: a srawny furry thing with improbably wide eyes. But then they launch themselves into the air, and they are transformed into a sleek gliding thing, like a swift kite, or an aerodynamic doormat. They slice through the air surprisingly quickly, and then flare up (stalling) just before their chosen tree, which they then land on. They crawl up the tree to a higher level on the trunk, and then repeat the gliding act.

A new study in the current issue of Proceedings of the Royal Society addresses the kinetics of colugo flight. Researchers captured a few colugos, shaved their backs (hah!) and then glued a little accelerometer there. This accelerometer works in the same way as the new generation of video game controllers: basically it can sense in what direction the colugo is moving, and how fast it's moving in that direction. The device looks like a little jetpack on the back of the colugos (as in the photo above), and it makes them look like some race of alien: a combination of the weird almost-a-primate morphology coupled with the shiny technological gadget latched to their backside. I'm not sure that I find the insights of the study all that fascinating (they basically confirm my common-sense read of colugo flight dynamics), but I think it's cool that people are out there quantifying such things using technology like this.

Accelerometer article in Proceedings of the Royal Society B.

Genetic relatedness of colugos to primates article in Science.


Eurekalert press release on the accelerometer study.

Labels: evolution, primates, tv

Breaking News: Series Of Concentric Circles Emanating From Glowing Red Dot

Labels: earthquakes, humor, tv

It appears that researchers have located a volcano under a thick mantle of Antarctic ice. They found the volcano's approximate position by mapping a layer of ash and glass shards within the glacial ice. The volcano erupted in or around 325 B.C., say Hugh Corr and David Vaughan, based on their study. (Both men work for the British Antarctic Survey.)

They initially detected the layer of volcanic debris through airborne radar-reflectance measurements. (At first they thought the reflective layer was the bedrock at the bottom of the ice, since it provided such a strong reflection.) Then they looked at the thickness of snow overlying this layer and correlated the ash deposit with eruption-linked acid-rich snow strata in ice cores that were taken in adjacent areas. The image here shows the radar-wave reflectance profile.

(According to my rough calculations, the vertical exaggeration of the cross-section is about 6x. )

This has been billed as the first time we've seen clear evidence of a volcano pushing its way up through the ice sheet in Antarctica, though similar eruptions have been observed in historical times in Iceland (like Grimsvotn in 2004). However, just this past weekend I watched an episode of the PBS series NOVA, which showed scientists working on a big ice coring project near what they interpreted to be a sub-ice volcano. There was a big depression, and ice was flowing into the depression (downhill) from all directions. Ergo that ice had to be going somewhere. NOVA's scientists posited it was being melted, and that meltwater was greasing the skids of the bottom of multiple ice streams which were cruising out of that area of the ice sheet. (These ice streams are just faster-flowing areas of the ice sheet, like currents zooming through ocean water, sometimes 50x as fast as the "background" rate of flow.)

The show got me thinking about another study, coincidentally also published in Nature Geoscience, although this one was in the inaugural January issue. It's a study of the Kennicott Glacier, in Alaska's Wrangell-St. Elias National Park:

The study was conducted by three researchers, all associated with the Institute of Arctic and Alpine Research: Timothy Bartholomaus, Robert Anderson & Suzanne Anderson. They measured a bunch of variables on the Kennicott Glacier, seeing which of them correlated with a rise in the glacier's speed. They found that an annual flood event from Hidden Creek Lake (HCL in part d of the diagram, orange line) occurred at the same time as the glacier's maximum speeds during the measured interval, the maximum discharge of the (downstream) Kennicott River, and a maximum electrical conductivity of the water in the Kennicott River (the bedrock beneath the glacier is halite-bearing). As this whopper of a graphic shows, Not only does the glacier speed up its horizontal motion during the flood (part b), but the whole thing actually rises up vertically too! (part c) Also, Donoho Falls Lake (DHL in part d of the diagram, blue line) downstream experiences a huge surge in water as the flood passes over it. Conductivity spikes during this same interval. Bartholomaus and the two Andersons propose that when the ice dam of the lake gives way and all that water surges into the glacier's channel, it overwhelms the capacity of the sub-glacial network of channels & raises the pore pressure of water within the ice. This extra pressure "inflates" the space between glacial ice & underlying bedrock, and the whole thing slides like an air hockey puck. At least, as long as the super-high pressure lasts. Once the flood ebbs, pore pressure in the glacier drops back down to levels that are easily counteracted by friction. The glacier slows once more to a "normal" pace.

This is very reminiscent to me of studies done on how an increase in pore pressure along a fault plane can trigger movement along that fault. When I took structural geology in college, the professor described an example from Colorado (I think) where the Army (I think) was injecting nerve gas down into the ground to get rid of it. The nasty nerve gas was dissolved in water, and the periodic injections of this solution correlated with a series of earthquakes (movement) along a previously-unknown subterranean fault. The injections increased fluid pressure in the pore space of the rock, and that "inflated" the space between the fault blocks, and the relatively minor shear acting on them was then enough to get the two to slide. I won't get into the whole Mohr Circle here, but I do recommend you check out the famous Beer Can Experiment to get an idea of how an increase in fluid pressure can cause an otherwise "stuck" fault to slide. Anyhow, I guess the base of a glacier is essentially a big fault, with one kind of rock below and another (ice) above. Same phenomenon, in other words, but different geologic context.

The Bartholomaus + 2 Andersons study also has some big global warming implications. The recent surge noted in Greenland's glaciers (e.g. Zwally, et al., 2002) may be explained by higher rates of surface melting (due to elevated Arctic air temperatures) which then produces lots of meltwater, which flows down through the glaciers to the bottom via meltwater channels which plunge through the ice. Via the mechanism explained above, the great ice sheet atop Greenland is reduced more rapidly than without the surface melting. One of these meltwater channels was featured prominently on the cover of the June 2007 issue of National Geographic.

So, with that, I think I'll end this blog post -- my thoughts went from volcanoes to ice streams & subglacial meltwater to fault slippage to global warming. I reckon that's just about enough... just about... but I also noticed something else...

A tangent about publication: The Corr & Vaughan findings will be published in the second issue of the new spinoff journal Nature Geoscience, but they were posted online over the weekend in advance of the actual print publication of that issue. An article in the New York Times alerted me to the study. I'm not surprised that Nature, like the Proceedings of the Royal Society, has taken to hatching specialty sub-journals to convey more articles each month. (An "about the journal" page appears on their website, if you're curious.) The image shown here with this post is from the Times, not the actual Nature Geoscience article.

References:
Hugh F. J. Corr & David G. Vaughan. (2008) "A recent volcanic eruption beneath the West Antarctic ice sheet." Nature Geoscience. Published online: 20 Jan. 2008. doi:10.1038/ngeo106

Timothy C. Bartholomaus, Robert S. Anderson & Suzanne P. Anderson. (2008) "Response of glacier basal motion to transient water storage." Nature Geoscience 1, 33-37. Published online: 20 December 2007 doi:10.1038/ngeo.2007.52

H. Jay Zwally, Waleed Abdalati, Tom Herring, Kristine Larson, Jack Saba, & Konrad Steffen. (2002) "Surface melt-induced acceleration of Greenland Ice-Sheet flow." Science 297, 218-222. doi: 10.1126/science.1072708

Also see:
Kenneth Chang. "Scientists find active volcano in Antarctica." The New York Times. Published online: 21 Jan. 2008.

Labels: antarctica, global warming, tv, volcano

I just got through watching the four-episode "Origins" series on PBS's show NOVA (not to be confused with NOVA, as in Northern Virginia Community College!). Hosted by the genial and enthusiastic director of the Hayden Planetarium, Neil deGrasse Tyson, the series explores how the Earth came to be, how life evolved, whether we're alone in the Universe, and evidence for the Big Bang. It's pretty comprehensive for just four hours of watching, and quite well produced. The graphics are excellent, and they offer casual interviews with top scientists like Frank Drake and Andy Knoll. The series is out on DVD, and I got it through Netflix, though it looks like PBS is going to keep broadcasting it in the future. Recommended!

Labels: astronomy, tv