Wednesday, October 31, 2007

GSA: getting there is half the fun

I live a seven-hour drive from Denver. There's an airport near me, but the flights are expensive and frequently delayed or cancelled, so when I have to go to Denver, I drive.

A seven-hour drive can be rough... unless it looks like this:

My drive takes me up into the headwaters of the San Juan River, over the continental divide, and into the headwaters of the Rio Grande, Arkansas River, and South Platte River. People go out of their way to vacation in the places that I have to drive through to get to Denver.

The photo is of the northern Sangre de Cristo mountains, on the eastern side of the Rio Grande Rift. The peaks are Precambrian igneous and metamorphic rocks, sillimanite grade and partially melted - I did my senior thesis research in the area. Further to the south, the Precambrian is covered by layers of sedimentary rock, all tilted towards the east, away from the fault. The range front is a normal fault, possibly still active. The valley is filled with sediments: lots of alluvial fan gravels, interbedded with lake sediments from wetter times. The western side of the valley is much less dramatic: hills of Tertiary volcanic rocks from the San Juan field are partially buried by the young gravels. Streams in the area feed an artesian groundwater system - as I drove across yesterday, I could see crusts of white minerals on the soil, left behind from evaporation of standing water. The Great Sand Dunes National Park is along the range front - the sand is carried into the valley by streams, and then blown back along the valley by the prevailing west winds. It's a particularly beautiful example of a half graben.

There was a session (that I missed, unfortunately) on groundwater and tectonics of the Rio Grande Rift. It focused more on the Albuquerque area (for good reason: there are a lot of people using that groundwater down there); the abstracts for the session are here.

I love that valley. High, open, dry. Snow-capped peaks. And a little bit of tectonics, where North America has been pulled a little bit apart, west of the plains and east of the Colorado Plateau.

Sunday, October 28, 2007

GSA: everyday science

There are stories about a session at the American Geophysical Union in 1966, when it finally became clear to the audience that sea-floor spreading was real and that the continents really did move. Apparently some other recent AGU meetings have had that sort of feel in sessions about climate change - Chris Mooney describes one in Storm World. But the Geological Society of America meetings that I've attended... they just haven't been like that.

Every talk is fifteen minutes long. Fifteen minutes, in which to make a case that one's ideas or data should change the way we interpret things. Fifteen minutes to convince a room of structural geologists that we really should start with equations of conservation of momentum, as Dave Pollard tried this afternoon. Fifteen minutes to try to explain why rotations determined from paleomagnetic data don't fit those predicted from estimates of strike-slip motion along Laramide structures. (If the model never fits the interpretations of the field data, something's got to be going on - either we don't understand the structures, or we don't understand what kind of rotation the structures should cause.) It's enough time to raise a few questions, maybe even to make a well-constructed argument... and then it's on to the next.

In part, it's the nature of science: most of what we do is incremental, fitting new data into existing models, tweaking the ideas here and there when the data don't quite fit with previous understanding. In part, it's the way the talks work: they are progress reports, ways to raise questions before submitting the long version of the research for rigorous peer review.

So what's the most interesting thing I saw today? Well, there was one talk (in a structure modeling session) testing a hypothesis for entraining layers of debris in the toe of a glacier... which concluded that, no, thrust faults couldn't form in a glacier. (It's nice to see someone come to a conclusion that, no, a model doesn't work.) And I learned, little by little, about mechanical modeling - but I didn't come away with the conclusion that my explanations for a certain group of structures have been totally wrong all this time.

My biggest conclusion for the day is that I need to do a better job of teaching quantitative skills in structural geology. Which isn't really a new conclusion at all.

But perhaps that is not so unsual.

And maybe, if I had wanted to have some paradigms shifted, I should have sat in the Mars sessions. (There will be another one tomorrow. I'm going to go, at least for a while.)

Friday, October 26, 2007

Pre-GSA Public Service Announcements

First, one future announcement: the Cutting Edge people are planning a follow-up session to the Teaching Structural Geology and Teaching Petrology workshops at the Rocky Mtn/Cordilleran Section GSA meeting (March 19-21 in Las Vegas). The abstract deadline in Dec. 11. The session isn't on the GSA website yet - look for it after the national meeting is
done. Oh, and there will probably be an associated field trip. I'm looking forward to the opportunity to discuss how to teach Cordilleran structure!

Now, about GSA...

Geoscience Educators Social Reception

Saturday, 27 October, 2007
5:00 - 7:00 pm
Colorado Convention Center, Hall F

Geobloggers dinner?

We tentatively planned to meet Sunday after the opening reception. I don't know the time or place. Sports bars may be rather crowded Sunday night...

World Series

If you've got a hotel room and a late plane flight, make sure to contact your hotel. Don't let your hotel room get given away to a baseball fan...

GSA. Be there.. or be a cricket fan, I guess. (I was going to say "or be a Yankees fan," but we can't all be originally from New England and currently from Colorado, and perfectly willing to switch allegiances depending on quality of the pitching on any given night. :D )

And with that, I've got a long but beautiful drive to make, and way too many exams to grade. Hope to see some of you in Denver.

Monday, October 22, 2007

Links: drought in Turkey & SE US, Tambora, visualizing climate change

Some links to things I've been reading (and thinking about for classes):

RealClimate has a guest post from Figen Mekik about climate change and drought in the Mediterranean. It's a great combination of a personal perspective (Mekik is originally from Turkey) and explanation of the processes involved. In particular, Mekik explains the North Atlantic Oscillation, which I've always found confusing... but which is kind of an Atlantic version of El Nino, and which can have an important impact on weather in Europe, North Africa, and North America.

John Fleck has been watching the drought in Georgia and blogging about what the historical record shows. Is the problem with climate, or with population growth, in this case? (The definition of drought, after all, depends on how much water a given area needs.)

For anyone who, like me, needs a good source of images for climate change lectures: the global warming art site. I recognize the graphs from the peer-reviewed literature (and the wiki pages associated with them have all the references). And it's really nice to have access to the graphics in color, and in an easy format for importing. (Thanks to Michael Tobis and John Fleck for the links.)

And, finally, remembering "the year without a summer" and the eruption of Tambora. I heard the story on NPR this morning while I was driving in. In 1816, people starved in Europe, and New England had snow in the middle of the summer... all because of the eruption of a volcano on the other side of the world. Tambora's eruption was bigger than Krakatoa's (which also had a cooling effect later in the century). (Thermochronic had a great post about Tambora, as well, and connected it to the writing of Frankenstein and with landscape paintings.)

Friday, October 19, 2007

Teaching: where did that water come from?

I've just started the water section of my intro class. Like usual, I asked students to raise their hands if their water came from a well, and raise their hands if it came from a reservoir, and so forth. Fewer than half the students responded in any way at all, even when I asked how many of them just get water from a tap.

It's not that uncommon. ("Trace the water you drink from precipitation to tap" is one of the questions on the old bioregional quiz... and it's asked, I think, because so few people actually know.) But this year, I responded a little differently. I told the class to go home and find out, and I would put an extra credit question on the weekly quiz.

And they did it.

It would have been pretty easy to cheat on the question, you know. I know where my local water comes from, but the students all come from different places. And a few students simply answered "a reservoir." But the vast majority of them told me more - much more. They told me where they were from. They told me the names of reservoirs and the rivers that they dam. They told me how far the community well was from their house. They told me that their wells hadn't gone dry, although the neighbor's wells have. One even told me about the Ogalalla aquifer.

I'm delighted. And I think they're ready, now, to talk about groundwater next week.

(And this, of course, is the real reason that I use extra credit: because sometimes students will take the opportunity and run with it.)

Interesting post about Japan earthquake early warning system

Sismordia has posted a really interesting description of Japan's earthquake early warning system. At the end, she asks for comments:

Call for comments: Are you living in Japan, or do you know people who are? Have you (or they) had to react to an Earthquake Early Warning yet? If so, please let me know how it worked, what went through your mind, what you did to prepare for the shaking, how you felt afterwards.

I'm curious, too, so if you know anyone who has experienced the system, please go over to her blog and describe your experiences.

Teaching with An Inconvenient Truth

I'm showing An Inconvenient Truth in class the week after next, while I'm away at the Geological Society of America meeting. I'm going to leave the class with questions to answer while I'm away. But... what should I ask?

I've used climate change to discuss the intersections between science and public policy before. I used to show What's up with the Weather?, a NOVA/Frontline documentary made after the Kyoto Accord was signed, but before the 2000 election. By 2004, it felt really dated, in part because of the four years of the Bush administration, and in part because study after study after study had come out showing that climate is changing now. So when An Inconvenient Truth came out on DVD last fall, I bought it and immediately showed it in class.

But I think I need a different approach to the discussion for the two videos. What's up with the Weather explained the science behind the greenhouse effect (and did a very nice job, I thought - there was a particularly good demonstration of the absorption of infrared radiation by CO2), but it also gave a fair amount of time to climate skeptics, and to people who had a variety of different views about what we should do, if anything. So I asked students to watch for the answers to a number of factual questions (such as what the greenhouse effect is, and what kinds of climate proxies can be used to infer past climate conditions, and what sorts of positive and negative feedback mechanisms can affect global temperature changes), and then I spent the discussion time talking about how to interpret media discussions of science. (We brainstormed lists of facts vs testable hypotheses vs opinions - I wanted them to leave the discussion ready to critically evaluate what they are told.)

That approach won't work for An Inconvenient Truth. In many ways, the movie is a piece of rhetoric... but it's rhetoric based on pretty solid science. (There's been a lot discussion lately about the UK court finding nine errors in the movie, and fortunately there are also some good discussions that evaluated the science behind nine points. Deltoid summarizes the response of a number of different climate scientists; RealClimate's summary is here.) And at the same time, it isn't hard to find critiques of the movie - try the Wall Street Journal's editorial page, for instance.

So I want students to think critically about everything that they hear and read. But, on the other hand, I don't want to encourage students to parrot the climate denialists - I want them to think about the science, about what's happened with CO2 and about the different sorts of effects that it can have.

So... any ideas about what I should do, or what kinds of questions I should ask? Should I ask about specific key points, to reinforce them? (I would love to send the students to the peer-reviewed literature to have them see what the experts really say. Unfortunately, our library is very limited - if it's not in Nature or Science, the students will have trouble finding it - and I think the students need somebody to translate scientific language for them. And if I send them to the web in search of more info, how will I make sure they are looking at reliable sources, and not climate-denial blogs? I don't want them to get in the habit of evaluating on-line sources by choosing ones that agree with their preconceived notions.)

(I do have another idea. I'm considering giving a pre-test and a post-test, same questions, and seeing if An Inconvenient Truth leaves the students with an improved understanding of climate change. One reason: I showed the movie to a math-phobic friend, and she said that she had never understood graphs before watching the gimmick with Al Gore on the lift. And that made me wonder if Gore explained the science more clearly than scientists had... which is the real reason why I show the movie in class.)

Wednesday, October 17, 2007

Rainbow... from above

While I was driving to work, the weather radio said the temperature was 36° F... and the dew point was 34. Huh, I thought. I wonder if it will be cloudy in town.

I could see the hills to the west as I pulled onto campus, and then the clouds started forming in front of them.

And then I saw this.

It started raining right after I finished taking a panorama of the entire double rainbow.

It cleared up in the afternoon. There's a fair amount of snow in the high country, above 10,000 feet or so. I didn't get outside to take another picture, though.

Anniversaries and missed opportunities

The Loma Prieta earthquake was eighteen years ago today.

And I mentioned it in one class already (as "the Big Enough One," in response to a question about the maximum possible size of an earthquake in a different tectonic setting). And I totally forget the anniversary.

Perhaps it's not that important to remember any more. I mean... the college freshmen were born in 1989.

Human memory really isn't long enough to handle geology, is it?

Monday, October 15, 2007

Accretionary Wedge #2: How the Earth Could Kill You

Civilization exists by geologic consent--subject to change without notice.

Apparently there is some controversy about whether Will Durant ever actually wrote that quote. But that doesn't really matter to geologists. We know it's true. Just ask the ammonites, or the residents of Pompeii.

But how, exactly, might the death and destruction occur?


Well, to start with, there's always fire.

Chris Rowan at Highly Allochthonous sees warnings for Naples, Italy in"A Tale of Two Volcanoes".

And on the North American plate, Yami at Green Gabbro takes a not-quite-boiling soak in the hot springs created by the magma of the Long Valley caldera.

And if the volcanoes of recent history are too tame, consider the Cretaceous-Tertiary boundary. The asteroid impact gets most of the press these days, but Chris (yorrike) at Good Schist points out that the volcanoes of the Deccan Traps did a number on the ammonites first.


From his perspective above a subduction zone, Miguel at MiGeo explains the dangers of tsunamis, in Chile and Indonesia. (English translation of the post is here.)

And I wasn't killed by the Loma Prieta earthquake (as you might have guessed), but I was shaken up a bit.


And, just when you thought it was safe to go back into the house, Brian reminds us that even fundamental forces of physics, like, for instance, gravity, are dangerous.

Hazards in general

It isn't just gravity. As Jim Repka at Active Margin points out, we wouldn't be able to live without disequilibrium. That's right. Thermodynamics is also out to get us.

And then there are the hazards of field work...

Those of us who live in arid or semi-arid environments know that the sun is not always our friend. Especially at noon in the summer. Lounge of the Lab Lemming has more about deadly evapotranspiration.

And Ron tells of a field assistant with walking pneumonia on the dreaded Mancos Shale, and also warns that the Earth is hungry.

So watch out.

The next edition of The Accretionary Wedge will be on November 15. Kevin Z at The Other 95% will be hosting the carnival, with a theme of "Geology and Life."

Also, an announcement for any geo-bloggers and lurkers who will be going to the GSA meeting in Denver in a few weeks: there are plans afoot for a geo-blogging meet-up/dinner on Sunday night. Ron has offered to make dinner arrangements. Keep a look out for the final arrangements.

Edit: I'm adding other posts as they come in. So far, Jim Repka has added dire warnings about equilibrium, and Dr. Lemming tells of the dangers of evaporation.

Not dead, but shaken

I really had no one but myself to blame.

Consider this: I chose my graduate school after a lovely late-March visit. But it wasn’t the California spring sunshine that sold me. Nope. It was a drive up Page Mill Road with two first-year grad students. A drive to the San Andreas fault.

When we got back, they pointed to the old, unreinforced sandstone masonry of Geology Corner. “They haven’t gotten around to reinforcing this side of the Quad yet,” they said. “So this could all fall down in an earthquake.”

We all laughed.

So, as I said, it wasn’t as if I hadn’t been warned.

On October 17, 1989, I had been a student at Stanford for three weeks. It was a beautiful afternoon, and I had spent it avoiding doing my homework, as any new grad student who hasn’t yet figured out that she isn’t still in college might do. Around 5 pm, I had finally settled down to work a little before supper.

And then the desk started to shake.

“Oh, cool,” I thought. “Maybe this is an earthquake!” I considered getting under my desk.

My desk started moving across the floor. I decided that maybe the door was a better choice.

I couldn’t stand in the door, so I sat and wedged myself in, feet on one side of the frame, back on the other. As the floor rolled like a ship in high seas, I yelled: “Is this an earthquake? Is this an earthquake?”

Then I heard the sound of glass breaking, and then all was still. Well, except for the fire alarm going off. I knew what that meant: time to evacuate the building. So I did.

It was hard to piece together the news that we heard over the car radio. The Bay Bridge had collapsed. San Francisco was burning. The aqueduct to Hetch Hetchy was broken. (The last one, fortunately, was untrue, and the fire in the city was restricted to the Marina District.) I did what any good geology student would do: I grabbed all of my camping equipment and prepared to survive for as long as necessary.

We slept on the lawn, afraid of aftershocks and gas leaks. The next morning, we snuck into a dorm to take a shower (because, you know, if there’s still water somewhere, one should always take a shower before the water is gone!), and then waited for news. Classes were cancelled; building inspectors had to decide what was safe and what was damaged.

By the end of the week, the “damaged” list included both my house (built in, I believe, the 1910’s) and Geology Corner.

I slept on at least three different couches that week. I learned everything I now know about earthquakes when the Geophysics Department decided to turn the event into a Teachable Moment. (It was a good idea, really. Though they still had a functioning building.) I missed getting to see Naomi Oreskes defend her dissertation. I packed my personal belongings into boxes in a moving truck, and my geology belongings into another set of boxes. It took a week to find a new place to live, and longer to find the location of the trailer which housed the new geology grad student offices. The post office never would forward my mail, because I had lived at a group mail address. For all I know, the Stanford Post Office is still throwing away my catalogues.

The aftershocks woke me up at night for the rest of the year.

We were lucky, in many ways. Neither my home nor my office (nor, for that matter, the Earthquake Engineering Building) was seismically sound. My house had a brick foundation; after the earthquake, it bulged in ways that a brick wall shouldn’t. (It was later condemned and torn down.) The sandstone of the Quad hadn’t held up particularly well in 1906, and it spent the 90’s braced so that the keystones would not collapse. (It was fixed and reinforced... eventually.) But nothing actually fell down on campus, except a chimney on another house, and a lot of bookcases. Further from the epicenter, a double-decker freeway in Oakland had collapsed, and people were killed.

But I survived with nothing worse than a lot of stress, and a good story to tell in class.

I am Sprawl

Bloggers Unite - Blog Action Day
I have a confession to make.

Every semester I lecture about global warming, about the greenhouse effect, about limited rainfall and groundwater and river water.

And then I drive home.

I live ten miles from where I work, on five acres near the end of a dirt road. My landscaping consists mostly of slabs of immature Tertiary sandstone surrounded by Gambel oak and fendlerbush. I share the five acres with six mule deer, hordes of jack rabbits and cottontails, and at least one bobcat... and that's just the larger mammals. It's a beautiful spot, and I chose to live there because I like having lizards as neighbors.

But it isn't a very environmentally friendly way to live.

Every day, I drive for half an hour to my son's daycare, and then drive back through town to get to the college. In the afternoon, I reverse the route. Sometimes I stop at Wal-mart on the way home - there are few choices for buying stuff for kids, in particular, in a small town. If I want to buy many books, or DVDs, or clothes, I have to order them through a catalog or over the internet, and they arrive in the back of a UPS truck. Except for a few months of farmer's market in the summer, my vegetables come from who-knows-where, even if I buy them from the organic food store.

If I want to go to GSA, or be part of a review panel for NSF, or be trained to use our ICP, or do research with a microprobe, I have two choices. I can fly to Denver or Phoenix or Salt Lake City, and from those cities eventually get anywhere in the world. Or I can drive: four hours to Albuquerque, seven hours to Denver or Salt Lake City, two days to get to the west coast.

I am not alone. There are houses sprouting from the old ranches along my drive to work, more every day, it seems. We all want space, deer, mountains.

Maybe I will install solar panels and make use of the 300 sunny days a year. But I'll have to carve out time from the commuting and the daycare and the grading first. Right now, I need to find time to replace the broken window shades that keep the house cool in the summer and warm in the winter. I'll get around to it soon. Promise.

Maybe I'll drive into town this weekend and take care of it. It's only ten miles...

Friday, October 12, 2007

IPCC and the Peace prize - historic moment for scientists?

Congratulations to the IPCC (and to Al Gore, as well) for being award the Nobel Peace prize.

And I've got a question. Is this the first time that a group of scientists has been awarded the Peace prize for communicating their results to the world? (Linus Pauling won in 1962 - but that was for activism against nuclear testing (according to Wikipedia). He won the prize in Chemistry for his science.)

I don't think Doctors without Borders quite count as scientists - and there again, they use their scientific expertise specifically to help people.

Are there any other scientists or science-related groups that I've missed?

(Edit: I did miss one: an agricultural scientist who won the Peace prize in 1970.)

Thursday, October 11, 2007

Accretionary Wedge #2, Earth Science Week, and Blog Action Day

Reminder: submissions for the second edition of the geology carnival The Accretionary Wedge (topic: "How the Earth Can Kill You") are due to me by 7 pm Mountain Daylight Time on Monday, October 15. (That's 1 am on Oct. 16, GMT.) Send the links to shearsensibility AT gmail DOT com, with "Accretionary Wedge" in the subject line to make the sorting easier.

I just noticed that the date corresponds to Earth Science Week. So I guess the carnival could be an Earth Science Week activity, in a way. (Should I e-mail AGI and tell them the geobloggers are participating?)

And the date also corresponds to Blog Action Day. And this year's theme is.... the environment. Should we register The Accretionary Wedge as participating? The understanding of natural hazards is one way in which geoscientists help humans figure out how to deal with our environment, so I think it's relevant. But I wonder what the rest of the geoblogosphere thinks.

Wednesday, October 10, 2007

More on the climate denial junk mail

Real Climate is putting together a Wiki debunking the "review article" included with the climate denial petition. If you've got expertise in any of the fields that have been messed up in the article, head over there and add your info to their project. (It's not my field, though I know enough to recognize misinformation.)

And if you've got colleagues who wonder what's going on with the petition, send them over there as well. Apparently geologists, biologists, engineers, and computer scientists at least were all targeted with this mail.

(Thanks, Brian, for pointing me to the link. But I'm curious - did the faculty in your department get this as well? Or did they avoid big-name research universities, and target those of us at small public colleges, community colleges, etc - people who have PhDs, but who have fairly small libraries and get a lot of papers via interlibrary loan, pdfs on author web sites, and so forth?)

Monday, October 8, 2007

Climate denial junk mail

Have other geoscientists out there been getting this junk mail?

I checked my work mailbox a few minutes ago, and along with advertisements for custom lab manuals and scanning electron microscopes, I got something rather odd: what appeared to be a reprint of a journal article debunking anthropogenic global warming, a photocopy of a 2000 op-ed article from the Wall Street Journal, and a request to send a petition postcard to a group called "GWPP."

I'm not going to sign it. But I'm curious how they got my address, and whether they're targeting all geologists.

I was also curious about the journal - "Journal of American Physicians and Surgeons." What is a medical journal doing publishing about climate change - even a review article about climate change?

It turns out that it isn't even a respected medical journal - it's known amongst medical bloggers for a lack of real peer review and a general anti-vaccine stance. And the authors of the article are running the petition drive, which is funded by "private non-tax deductible donations by interested individuals."

I'm embarrassed for the 19,000 scientists who have signed the petition. And I'm embarrassed that anyone thought I would be likely to sign it.

Sunday, October 7, 2007

In which I go hiking with the kid and see cool minerals... like ice

There’s a lot to be said for hiking with a four-year-old. Not in terms of aerobic conditioning, and not when the goal is to scout a new field area. And, yeah, it’s important to have the right food as a bribe, and to stop frequently. But fresh air, beautiful scenery, and family time... it’s hard to argue with that. Especially with scenery like this available on a mile-long hike.

Spud Lake is about a mile up a gentle trail, up in the aspens around 9700 feet. It’s high enough that there was frost on the ground today, even at mid-morning, and the high peaks surrounding it were dusted with snow. The trail was a bit muddy, though, so it was pretty slow going. We stopped to pick up a stick that looked like the letter “J,” and to scramble around on rocks, and to look at quartz veins.

My son was fascinated with the quartz, so I pointed out that the ice made crystals, too. We picked up a frost-blackened aspen leaf so he could see the crystals on its sides, and discovered that the entire bottom was covered with them. While he was looking at the leaves with a magnifying glass, another family walked by, and the boy said: “Have you seen THIS?”

He pointed to something that looked like white hairs on an over-excited yeti. Fibrous ice crystals, holding up pebbles and leaves and bits of frozen dirt. Every shadowed spot was covered with them, when we stopped and looked. On the hillsides, on the trail... everywhere.

They looked, actually, like vein fillings – fibrous vein fillings. Perhaps I shouldn’t be surprised – ice is, after all, a mineral, if one that melts readily under earth’s surface conditions. And like fibrous veins, I think I could figure out a deformational history from some of them.

A lot of the fibers were vertical – they came straight out of the ground, like hairs standing on end. But some of them were curved – sometimes all the way over, so that their pebble or dirt dangled from a curl. I have no idea how these form, but I’ll make a guess: the pebble or dirt is particularly cold, and the ice first nucleates on its bottom side. The crystal grows down, getting water from soil moisture. And sometimes, the pebble or dirt is heavy enough that the crystal bends under its weight. The crystal keeps growing straight up from the bottom, but the top becomes curved.

There were probably ways to test those ideas... but the four-year-old started getting impatient.

He smashed the ice in a few puddles, and then we headed up the trail.

Saturday, October 6, 2007

Misleading headline of the day: groundwater and climate change

From ScienceDaily and the US Department of Agriculture: ”Climate Change Likely To Help With Groundwater Recharge”.

Image source:
I get my water from a well that runs dry every so often. And I’ve heard Jonathan Overpeck talk about how global warming may affect the southwestern US - in particular, how it may affect our pattern of snowfall and snowmelt, and therefore exacerbate our current drought. So I was particularly curious about where, and under what circumstances, increased CO2 would lead to increased groundwater recharge. (The groundwater situation depends, after all, on many things. What’s the nature of the aquifer – is it shallow or deep, spatially restricted or regional? What kind of rocks is it in, and how and where do they connect with the surface? What’s the land use, the vegetation, the rainfall, the snow pack?)

So I checked out the actual paper. It is focused on modeling the effects of increased rainfall on two areas in Australia with different seasonal rainfall patterns. The study’s particular contribution was modeling the effects of plant growth on recharge – previous studies had left out the effects of transpiration.

Probably the most important point left out of the press release had to do with the assumptions: in these two areas, global climate models predict rainfall to increase (14% in one area, and 37% in the other). The study therefore shows that increased evaporation and transpiration shouldn’t use up the increased rainfall, and some of the water should go into the groundwater. And that’s an important result, and the study demonstrates an approach that could be used for other scenarios.

But as the authors themselves say in their conclusion:

The direction and magnitude of the change in local recharge depended on the combination of climate scenarios, vegetation, and soil properties. It is not possible to make generic conclusions about climate change impacts based on this limited sample of climatic zones in Australia.

(Their words; my emphasis.)

Contrast the conclusion of the press release from ScienceDaily:

In both locations, changes caused to soil, precipitation and plant transpiration by simulated climates with twice the existing CO2 led to significant changes to the rate of groundwater recharge. Water recharged from 34 percent slower to 119 percent faster in the Mediterranean climate, and from 74 to 500 percent faster for the subtropical climate.

While the opportunity for decreased recharge rates exists, the general trend is towards increase. Future research will investigate whether those changes would benefit or harm those ecosystems.

The press release never mentions that the simulation included an increase in rainfall... which is probably the single most important factor in increasing groundwater recharge.

And the headline. That headline. “Climate Change Likely to Help With Groundwater Recharge.” The headline does exactly what the authors of the study warn against doing: it makes generic conclusions from a limited study of particular places.

Well. I don't live in Australia, and climate models predict less rainfall for my corner of the world. So regardless of the headline, I'm not going to count on my well recovering any time soon.

Thursday, October 4, 2007

Landslides, nature, and the blame game

There was a big landslide yesterday near San Diego, California. Landslides in coastal California are not at all uncommon – the mountains are steep, and young, and many of them are made of rock that falls apart easily. So I wasn’t surprised to hear about it, but my students asked about it this morning, so I looked it up on CNN.

And at the bottom of the story, I found this:

Pat Abbott, a retired geological sciences professor at San Diego State University, told the Union-Tribune that Mount Soledad is made up of weak layers of rock and that the culprit in the landslide is nature.

Now, a bit of background may be in order here. Local residents are blaming the city for the landslide – they claim that the city didn’t repair leaky pipes, including a fire hydrant, and that the water caused the landslide. So Abbott pointed out the geologic background of the area, which makes it particularly prone to landslides: the mountain is underlain by weak layers of sedimentary rock that slope in the same direction as the hillside. In other words, the hillside was going to slip someday. (In fact, there was a landslide in the 1960’s when the area was first developed, and there were two landslides in the 90’s.)

But the quote on CNN’s web page doesn’t go into that background. Instead, it simply says “the culprit... is nature.”

There’s something about that statement that suggests the inevitable, the uncontrollable, the unpredictable. There’s nothing we can do. It’s natural. It reminds me, actually, of statements by Robert Murray, owner of the Utah mine that collapsed in August. (He tried to avoid blame by arguing that the collapse was natural - in that case, that it was the result of an earthquake.) If nature is at fault, then how could a mere human have done anything?

But I don’t buy that. Nature isn’t wholly unpredictable. Sunrise and sunset are natural. So are tides. And so, for that matter, is gravity... which is ultimately the cause of both landslides and mine collapses. Now, the response of earth materials (be they coal or soil) can be difficult to predict, but that doesn't mean we know nothing - it simply means that we can’t draw a single clear line between “safe” and “unsafe.” And hillsides that have slid before fall into the category of “probably unsafe... eventually.”

So do I think the city is responsible? Probably not (although adding water to a dangerous slope could change a slope from “potentially unstable” to “oh s*** let’s get the heck out of here”). But I don’t think that a sense of fatalism is the only other possible response.

Nature can be dangerous. And it’s more dangerous in some places than others. And we already know a lot about where those places are.

So maybe people should pay attention to dangerous geology. On steep hillsides, yes, but also in flood plains, and along coasts. Because losing a house is horrible and tragic, and it would be better to avoid it happening in the first place.

Pat Abbott (who is also the author of a textbook on natural hazards) knows this, by the way. The CNN story ends like this:

"Gravity pulling on the incline is pulling down masses of earth and those masses of earth have houses on top of them," Abbott told the paper. "It's a geologically bad site and should not have been built on to begin with."

Tuesday, October 2, 2007

Where on (Google) Earth #56

I found the pink caldera on the China/North Korean border, so it's my turn to post something.

Brian suggested that people wait until they're allowed to post the answer (by the Schott Rule - to wait an hour for every WoGE round you have won). His argument was that people wouldn't even bother trying if they knew the puzzle had already been solved. I'm not going to invoke that rule - personally, I like looking for the places because I learn new things about parts of the world that I will probably never visit. (For instance, I didn't know there were any volcanoes where the last puzzle was located.) And a lot of time I look but don't answer, because I'm too late, or because I'm too busy to take on the next round.

Anyway. If you have feelings one way or another, please mention them in the comments - even if you don't solve the puzzle. (Or especially if you don't solve the puzzle.)

And with that said... here's the next image. It's an oblique view.

The Schott Rule is in effect. (That is, wait an hour for every Wo(G)E round you have won.)