Sunday, September 30, 2007

Accretionary Wedge 2: Total Destruction, coming October 15

I'm hosting the second edition of The Accretionary Wedge here on October 15. The theme: Natural Disasters Waiting to Happen. (Or ways the Earth can kill you, or doom & gloom.)

I'll take submissions until 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.

Tell your script-writing friends that the plot for their next disaster movie will be here. And your rock-paper-scissors-playing friends will learn exactly why it is that rock crushes scissors.

Friday, September 28, 2007

Undergraduate research at GSA Cordilleran/Rocky Mtn meeting

A new theme session for next year's GSA Cordilleran/Rocky Mtn section meeting in Las Vegas has just been added: an undergraduate research poster session. If you teach undergraduates (or did research as an undergraduate), you may be used to these sessions - the Council on Undergraduate Research sponsors them every year.

This year, the Cordilleran/Rocky Mtn session got lost in the process of planning a joint meeting.

But it's scheduled now - Jeff Marshall (Cal Poly-Pomona) and Bill Dinklage (Utah Valley State College) will be co-convening it.

Abstract deadline is December 11. If you are an undergraduate doing research, or if you are a faculty member advising undergraduate research... well, I hope to see you there.

Thursday, September 27, 2007

Shedding light on a black box

Chris Rowan posted earlier today about a heart-stopping experience – the sudden fear that there was something wrong with his data. (He was wrong, thank goodness, but he has some interesting things to say about science’s self-correcting mechanisms... or not.)

Me... I teach. I mean, I do research as well, though for the past fourteen years it has all been collaborative with undergraduates (and therefore slow, and with many backtracks and sidetracks as student interests diverge from mine). But really, my job is to teach undergraduates to become scientists. And as a result, I’ve been worrying a lot about how to get students to think about the data they collect: What does it mean? Is it reliable – were there any problems with the way it was collected? Does it fit with their expectations?

Four years ago – actually, the month after my son was born – we (that is, a colleague and I) received an NSF grant to buy a new ICP-OES. An “inductively coupled argon plasma optical emission spectrometer.” It can measure the concentration of a lot of different elements dissolved in water (and can measure rock chemistries if you can dissolve the rock in a strong acid), which means it can be used for a variety of environmental geology and igneous petrology projects. It was our department’s first analytical instrument (well, aside from an X-ray diffractometer that was already broken when a research university donated it to us), even though the department required an undergraduate research thesis from all the majors. We noticed that students didn’t seem to think very carefully about their data when they sent samples out to a lab and received some numbers in return – they weren’t aware that each technique has error associated with it, and they treated their data as if they were infallible.

But now we’ve got an instrument in-house. My colleague is working on getting it ready to analyze major and trace elements in igneous rocks. A few students have used it for water quality data. I’ve used it to collect data for intro class projects... but it’s still a black box to our students. And it’s a bad idea to treat it that way.

So I’ve been developing a research exercise for our Earth Systems Science course. We’ve had a group research project in the past, but it hasn’t worked all that well. The students had to come up with their own idea for a project, and design their data collection, and implement their project... on their own. Perhaps a good idea for graduate students. Not so good for students who haven’t even thought about stream flow, or what minerals are found in which rocks, or how weather systems form. The projects are frustrating for the students, and it isn’t really clear that the students are learning much. So I want to ditch the old project model.

My new idea is to have all the lab sections monitor a small local river. Each lab section will be responsible for collecting data on one of eight reaches along the river, and groups within the lab will measure discharge (amount of water going down the river), sediment load (probably as turbidity, but I would like them to also think about bed load), and water chemistry (two different groups, one responsible for nitrates and nitrites and phosphates and chloride and pH and TDS, and another responsible for cations, measured with the ICP). We would monitor the same reaches every year, fall and spring, and students could compare their data with previous years, other seasons, and other reaches. I’ve got a thesis student collecting baseline data right now – and he’s also making a GIS database that includes current land use (this could change through time), the location of irrigation outflows (this isn’t an entirely natural river – human influences are significant), and surface discharges of formation water from natural gas drilling.

So, all well and good. I’m excited about having the students be part of an organized study, and about having them compare data without having to collect a thesis-worth. But that still doesn’t necessarily solve the problem of getting the students to think about the quality of the data.

So I’m doing an experiment this semester. I’m making the students do some prep work before we actually collect the data. Last week each group had to give me a short background write-up – what data were they collecting, and how would it be measured, and what factors would control whether it would be high or low. This week they turned in another short write-up: what did they expect to find? Some of them found historical discharge measurements. Some checked out River Watch data from the local area. I’m hoping that the pH group will tell me that 7 is neutral, and that surface waters are usually slightly more acidic than that, and that the ICP group will tell me that Ca, Mg, Na, and K are likely to be a lot higher than Pb. (Well, I sure hope we don’t find measurable Pb.)

My hope is that, by making the students think about the units and quantities that they will be measuring, that they will notice if the numbers are unreasonably high, or unreasonably low... and check to see that the correct switch is flipped, or that the sample probe is actually in the water, or that they used the same units to measure the river’s width and depth.

And I’m hoping that the length of the assignment will allow the students to think more than they normally do in a three-hour lab.

We’ll see. The intro students probably won’t spend time fretting over whether one element is interfering with another in the ICP analysis – they won’t become analytical chemists while doing an intro geology project. But maybe the numbers will mean more to them.

Tuesday, September 25, 2007

Mapping as a philosophy of life... or, you know, not.

Today, my sophomores began making their first maps. There's something kind of special about that first map. Maybe it's the way all those rocks first begin to fit together into a spatial context. Maybe it's the regression-to-childhood feel of all the coloring. Whatever it is, I like getting to experience it anew every year.

We started the project the usual way. I have the students look at some geologic maps, and we talk about the information conveyed on them, and about what a "contact" is, and about the importance of measuring the orientation of the beds. And then we go outside, to a gulch near campus, and hike up through the shale and sandstone and coal (Ron: we map the top of the Mancos Shale and part of the Mesa Verde Group), talking about how to tell the units apart, and how mappable units usually contain more than one rock type.

And then we climb a rather gnarly mountain-bike trail, and I find out which students run trail marathons in their spare time. And we get beautiful views at the top. (And, as usual, I don't take pictures because I forgot my camera. But, yes, it did snow a little this weekend, above 10,000 feet or so.)

And then we get to the map area. I talk them through orienting the map, and then they have to locate themselves. There's a perfect point to sight towards - I don't allow GPS units on this first project, because it's always good to have an alternative to technology for when the batteries run out - and the students pull out their compasses and their protractors and get to work.

Today I was feeling a bit punchy, though. So when they had measured their bearings and drawn their lines, I said:

If you want to make a map, first you have to find yourself.

And then I though: see, every college student needs to take geology. Not because they need to understand earthquakes and volcanoes and floods and landslides and groundwater and coastal erosion and the sources of all those resources they use every time they go skiing.

No. Because geology teaches them to find themselves.

Perhaps this is why geologists are so down to earth.

Monday, September 24, 2007

What I get for being in the office at 4 pm...

Every now and then, we get someone coming by the department, wanting help finding or identifying a rock. And it's great to help them - I've helped an archeology student identify rocks that had been used as tools, and I've disappointed a number of people by telling them that their rocks weren't meteorites, or gold, or dinosaur bones.

And then, sometimes, we get rather odd questions.

A guy just stopped by the office to ask about a mysterious rock found only in the San Juan Mountains above 8000 feet. Apparently it is made entirely from magnesium, and if someone bathes with it for three hours a day in a cast-iron bathtub, their hair will turn from grey to natural brown. And somehow it keeps skin from aging. (All this was supposedly carefully researched and documented by a Dr. Norman Shealy, a medical doctor who practices alternative medicine and owns his own university in Fair Grove, Missouri.)

Anyway, the guy wanted to know where to find the miracle rock.

Then he wrote down the name of the rock on a scrap of paper.

WELDED TUFF [Example picture here.]

I just about fell on the floor laughing. (Well, ok, I didn't. I politely told him that welded tuff was not that uncommon of a rock, and that, yes, you could find lots of volcanic rocks near Wolf Creek Pass. And I brought out a sample of a welded tuff from California. He said my rock was totally different, that his rocks had CRYSTALS in them. I told him that different volcanoes produced different-looking tuffs, but he wasn't convinced.)

I gave him the name of an emeritus faculty member who is writing a book on the eastern San Juan Mountains. Maybe the guy will listen to a grey-haired gentleman; he clearly did not think that I was a scientist on par with Dr. Shealy.

[Edit: Maybe, on the other hand, welded tuffs can help you solve an ignimbrite flare-up.]

Saturday, September 22, 2007

Let it snow!

Here's the National Weather Service's forecast for my county for tonight:


Thought #1: Yay! Must remember to grab camera when it clears. Maybe I'll be lucky and have the first clear day be Tuesday, when I'm going to be on a ridge with a view, teaching students to map.

Thought #2: On the other hand:


Well, I think the field area is below 8000 feet...

Thought #3: I love teaching in a science where I occasionally have to scrap a lab because of an early snow storm. :D And where my "work shoes" are Montrail Hard Rocks.

Edit: Oh, and Thought #4: Today is the equinox. Happy fall to those in the northern hemisphere, and happy spring to everyone in the southern hemisphere! (That goes double for Alessia in Antarctica.)

And Thought #5: I hope this storm's most intense rainfall is hitting north of the Four Corners, and Brian's field trip to the Guadalupes hasn't suddenly turned miserable. Rain is good... unless you're in a tent. Or are trying to get across flashy streams.

Earth in 250 million years?

Today's astronomy picture of the day comes from Chris Scotese's Paleomap Project. I'm amused that the astronomers have used two geology images this week - I mean, it isn't as if astronomy is lacking in amazing images or anything. But I'm also curious what people think of the assumptions behind the future projection.

Here's the map projected only 50 million years into the future:

He projects that new subduction zones will form along the east coasts of North and South America, and in the central Indian Ocean. I'm guess that he's assuming that, when oceanic crust reaches a certain age, it will begin to subduct. I've heard that argued before, and it seems reasonable to me, but...

Why not subduction off the coast of Europe and western Africa? Is there anything about the North American side of the Atlantic that would make it more likely to form a new subduction zone? (And where's the youngest subduction zone on Earth now? And is there any evidence of how that subduction got started?)

Arm-waving and random speculation welcomed. Heck, encouraged. I've got a few more weeks before my Tectonics class starts talking about subduction zones, and they always seem to ask questions like "But how does subduction start? Huh?"

(Actually, Scotese asks some of these same questions on his "more info" page. And he speculates that the Caribbean and Scotia arcs will propagate; that's why there will be volcanoes on old New York and not on Ireland.)

AAPG recants on climate change... a little

I was at a dinner meeting/talk with a lot of oil & gas geologists (and geophysicsists) last night, and I learned that the American Association of Petroleum Geologists has revised its position statement on climate change.

For some background: as recently as mid-summer, the AAPG had an official position statement that emphasized the role of natural processes in controlling climate, both in the geologic past and in the present. It specifically mentioned things like solar forcing mechanisms (which have been disproven as mechanisms for recent climate change). It talked about needing more research (which is all well and good, but, well... there has been a lot of research already, and it's pretty darn conclusive).

In short, the old statement made geologists look bad - it made it look as though we didn't respect the work of climate scientists (who, in many cases, work in the same academic departments with geologists). And I think it made geologists look like bad scientists, period.

Well, apparently enough AAPG members complained about the statement, and it's been revised. It is still pretty conservative, talking about the need for more research. But it does include statements like:

"- AAPG supports reducing emissions from fossil fuel use as a worthy goal." (However, the statement is weakened by implying that this requires an economic tradeoff.)

"- AAPG supports the pursuit of economically viable technology to sequester carbon dioxide emissions and emissions of other gases in a continuing effort to improve our environment and enhance energy recovery."

"- AAPG supports measures to conserve energy, which has the affect of both reducing emissions and preserving energy supplies for the future."

The opening paragraph makes some pretty weak statements:

"Although the AAPG membership is divided on the degree of influence that anthropogenic CO2 has on recent and potential global temperature increases, the AAPG believes that expansion of scientific climate research into the basic controls on climate is important."

The climate change skeptics are still there... but AAPG is changing. Slowly.

[Side note: I'm not a member of AAPG; I'm more interested in rocks that are too hot for oil.]

Friday, September 21, 2007

Structural geology and tectonics: the past, the future?

The newest newsletter from the GSA Structure/Tectonics division is out, and there's some interesting historical stuff in it. The current division chair, Bill Dunne, was working on revising the by-laws, and he discovered that the definition of the division needed revising. Eric Erslev, the incoming chair, is going to be leading a discussion at the division business meeting about what "structural geology and tectonics" means today. (Oct. 30, 5:30 pm. I'll be sitting in the back with my Advanced Structure students, ready for a conversation about what the discussion really meant.)

The original 1981 definition of the division is pretty intriguing (as Bill Dunne pointed out):

Of general interest are process-oriented research, mechanical interpretation, and field examples that are sufficiently well-documented so as to serve as models for the interpretation of other areas. Mountain-belt structure and tectonics would lie within this range of interest, but one would probably exclude geometrical and plate tectonics, a topic adequately covered at the AGU meetings. (emphasis mine)

Wow. In 1981, the new GSA structure/tectonics division considered plate tectonics to be a specialized concept, relegated to discussion at those crazy AGU meetings. And here I had thought that my high school earth science textbook was absurdly out-of-date, leaving out any significant discussion of plate tectonics in the early 80's.

And now, plate tectonics is so integrated in every aspect of geology that it is difficult to say what it should or shouldn't include. And that makes it hard to decide what to cover in an undergraduate tectonics class (such as I'm teaching this semester*). I just finished talking about various geophysical techniques that were important in developing plate tectonics (and which are still important in understanding tectonics). I'm going to spend most of the rest of the class talking about how various tectonic settings are recorded by different types of rocks, and about how continents behave (what do you do with rocks that don't behave like rigid plates, anyway?), and about studies of other planets that don't have plate tectonics, but do have mountains.

So I'm curious: what does "tectonics" mean to the geoblogosphere? (And is it arrogant for the structural geologists to claim it as theirs?)

* In case it's hard to keep track of what I'm teaching: currently I'm teaching Earth Systems Science, Geologic Methods, Plate Tectonics, and Advanced Structural Geology. And labs. If I'm missing from the geoblogosphere next week, it's because I'm grading too many exams.

Thursday, September 20, 2007

Where on (Google) Earth #50

I found Diamond Head, so it's my turn to post Where on (Google) Earth #50. (It feels wrong to do this while Brian is off on a field trip, you know?)

The Schott Rule is in effect: please wait one hour for every time you've answered a WoGE challenge. (I'm posting at 9:15 pm Mountain Daylight Time, which is... ummm... 7:15 am UTC. I think.)

Tuesday, September 18, 2007

spectacular volcanic eruption photo

An amazing photo of the volcano Tungurahua (in Ecuador) was posted as today's Astronomy Picture of the Day. (I'm going to link rather than posting the picture; the picture is copyrighted.) You can see lava flows pouring down in all directions, and a blast of dark tephra blowing off to the side. You can see the prevailing wind direction on the photo, too: the wispy clouds (almost lenticular?) are typical of clouds on the windward side of a peak, and there is a little snow on the windward side, as well.

The photo was taken by Patrick Taschler, who has other really beautiful photos of the eruption animated on the front page of his site.

Friday, September 14, 2007

Indonesian earthquakes: just foreshocks of the Really Humongous One?

Kerry Sieh thinks the M8.4 and other recent earthquakes off the coast of Sumatra might be essentially foreshocks to a larger, M9+ earthquake:

"No one can say whether it will be in 30 seconds or 30 years," he said. "But what happened the other day, I think is quite possibly a sequence of smaller earthquakes leading up to the bigger one."

(Quote from yahoo's news, but I've seen essentially the same report other places.)

He's published a lot of stuff about the Sumatra earthquakes since 2004, and I haven't read any of it, so I'm not sure which of several reasons he may have for his statement. (He has worked out the paleoseismic history of the subduction zone, so he may be thinking about recurrence intervals - typical times between major earthquakes on a given fault zone. He could be thinking about seismic gaps - areas of the fault that haven't had as many earthquakes, and are therefore probably more prone to slip. He could be thinking about the M 8.4 earthquake as a foreshock - a smaller earthquake that precedes a larger earthquake. He could be thinking about stress changes as a result of the 2004 M9 earthquake - something similar to the work that's been done on the North Anatolian Fault in Turkey, except on a subduction zone.)

[Edit: I suppose Sieh could also be making a far more basic point: the subduction zone is capable of larger earthquakes. The news may simply be a good opportunity to remind people of that fact, just like little earthquakes in LA or SF are a good opportunity to remind people that California is earthquake country.)

It feels like studies of earthquake mechanics are on the verge of really understanding the process better. It's exciting... though for the sake of Sumatra and people living beside the Indian Ocean, I hope Sieh is wrong.

Wednesday, September 12, 2007

Mw 8.4 Sumatra earthquake

There was a Mw 8.4 earthquake off the coast of Sumatra about three and a half hours ago. It generated a tsunami locally, at least.

The earthquake occurred on the same subduction zone as the 2004 Boxing Day earthquake that generated the huge, devastating tsunami, but it's on a segment further south and east:

(Map from USGS page... didn't copy well. Sorry.)

That means that the tsunami's propagation pattern should be different this time - and that different places are at risk.

The USGS pages for the earthquake have some good graphics showing a lot about the geology of the quake already. For instance, there's a cross-section of the seismicity that should be good for showing people what a subduction zone looks like, and the map on the map on the summary page already shows the focal mechanism. (Shallow thrust fault, dipping north... if you want to show anyone a shallow subduction zone focal mechanism, it's a really good graphic.)

From first glance, it seems that there has been a progression of subduction-zone earthquakes along that plate boundary: the big M 9 earthquake in 2004, then a good-sized (M8?) along the segment just to the south in 2005, and now another M8 along the next segment south. I'm curious to see where the slip on this earthquake initiated compared to the rupture zone of the 2005 earthquake, and whether the stress changes as the result of previous earthquakes predicted that this most recent rupture zone became closer to failure because of the earlier earthquakes.

[Edit - I'm getting e-mails from the USGS bigquake server, and it looks like they're recalculating the moment magnitude. Which might make this a good time for an explanation of the different ways of measuring magnitude, especially since Alessia has just posted a great explanation of the difference between earthquake magnitude and earthquake intensity. I can sort of explain the differences, but if there's anyone who does the real moment magnitude calculations, I would love to hear how they are done in practice.]

Tuesday, September 11, 2007

Fun with extra credit (but is it fair?)

Janet at Adventures in Ethics and Science asks: Is Extra Credit Fair? I’m going to answer here, rather than comment on her blog, because the answer is going to be a bit long.

Well, actually, the answer could be short: I don’t think that extra credit is fair unless all students are given the same opportunity, and I don’t think that an instructor should be expected to do additional grading at the end of a semester. That’s what I consistently tell students who ask to do extra credit to save their grades at the end of a semester.

However, I do think that extra credit can be used in ways that are fair to the students and the instructor. Sometimes I even include extra credit in the syllabus; other times I take advantage of opportunities that arise during the semester. All of the exercises have a few things in common: 1) they involve thinking about the class material, but in an unusual way, and 2) they sound fun to me. (Oh, and all students are given the opportunity to do the extra credit work, and I announce the opportunities well in advance, both during class and on the class web page.)

Example #1: Where on (Google) Earth?

I give weekly quizzes in my intro Earth Systems Science class. I don’t want to let students make up the quizzes late, mostly because I want to be able to grade the quizzes and give them back as soon as possible. But I know that Life Happens, and sometimes it happens on a Friday, and I don’t want to have to judge whether a student was genuinely ill or whether a death in the family has actually occurred or whether other horrific things have happened. I don’t want to be insensitive, but I also don’t want students to take advantage of my empathy. And I have a terrible internal lie detector, and I don’t want to have to rely on it.

So I don’t let students make up quizzes. But I do give them opportunities to replace their grade. I’ve done a variety of different things in the past, but this year I’m stealing an idea from the geoblogosphere and giving them “Where on (Google) Earth" challenges. Every Wednesday, I put up a new Google Earth image, and students have a week to e-mail me with 1) the location and 2) information about the geology of the area. I grade the answers on the same scale as the quizzes (4 points for either the location or the geology; 5 points for both; 3 points for an incorrect guess - it's possible to get anything from 0 to 5 on the quizzes, but I decided to be more lenient with the EC), and when the end of the semester rolls around, I’ll replace the low quiz grades with higher WoGE grades.

I’m hoping that the process of looking at Google Earth will help the students visualize things we discuss in class. (Later on, the students will need to use some geologic thinking to narrow down locations. So far, I’ve just been using locations in the news, because I didn’t feel like giving images of giant mine pits for the minerals week.) And maybe, just maybe, the students will get curious about what they see, and want to know more.

So far, about a quarter of the students have been participating. When I give the first exam, I’ll see if students who have been doing the challenges also do better on some questions. (I’m guessing that Google Earth might help them think about things like the locations of different types of plate boundaries, or where different types of volcanoes would be found. But we’ll see if that’s the case.)

Example 2: Bad geology movies.

During previous semesters, I’ve given a different quiz-make-up option. I had a list of bad geoscience movies (The Core, Dante’s Peak, Volcano, The Day After Tomorrow...), and I let students critique them for extra credit. Students could watch as many of the movies as they liked, and then needed to give me a one-page write-up about the geology in the movie (good and bad). No discussion of acting allowed... just critiques of the geology.

It was fun, but I was getting tired of seeing the same discussions every semester. Plus I wanted to be able to mock the movies in class myself. And the extra grading was a fair amount of work for me.

I don’t know if the students got much out of the exercise. (A number of them thought it was fun, though, which is worth something.)

Example 3: Halloween costumes.

Occasionally I will spontaneously agree to a student-suggested extra credit assignment. For instance, one year I had a midterm exam scheduled for Halloween. A few weeks before the exam, I started reminding students of the date, and was greeted by howls of dismay. I just cackled evilly in response. (I mean... it was Halloween. What did they expect? Glinda the Good?) But then one of the students asked: “If we wear costumes, can we have extra credit?”

I thought about it for a moment, and agreed, with one caveat: the costumes had to have something to do with geology, and the students would have to explain them to me.

I didn’t think anybody would take the challenge. I mean, it’s kind of embarrassing to walk around campus dressed as the San Andreas Fault all day, even on Halloween. But about a quarter of the class showed up in costume. And some of the costumes were fantastic. (There was one really spectacular fault... his costume was so heavy that he could barely walk with it on. And the San Andreas kids did a very nice earthquake demonstration.) My favorite costume, though, may have been the kid who explained how his ripped jeans represented mechanical weathering. It was just a brilliant way of showing me that he understood the concept.

The grades on that exam were higher than usual... even before taking the extra credit into account. So I think that the assignment was worth it – it got the students to think about the exam material in a creative way, and somehow that helped more than the usual cramming would have.

Monday, September 10, 2007

myth-busting: what's a teacher to do?

I just finished talking about the interior of the Earth to my intro class. I drew (semi-)concentric circles. I passed around pieces of peridotite from the Alps. I talked about squishiness in the asthenosphere. I made fun of The Core.

And I'm willing to bet that on Friday, when I start talking about the tectonic origins of igneous rocks, a large fraction of the class will believe that the mantle is liquid. And another large fraction of the class will think that most magmas come from the outer core.

There have been papers in the Journal of Geoscience Education about ways to recognize student misconceptions in order to correct them, and I've tried a lot of the techniques. But maybe there's a fundamental problem with myth-busting.

Last week, the Washington Post published an article about psychology research on the persistence of myths. One study followed adults who had read a flyer from the Center for Disease Control on facts about the flu vaccine - three days later, older adults remembered 40% of the myths as factual. To make matters worse, they thought the CDC was the source of their information. (Younger adults did better, but not that much better.) Other studies found that repetition, regardless of the source, makes people remember statements as true... and that people forget the not part of a statement after time.

So when I say "the mantle is not a liquid," that might make students remember that the mantle is liquid - and they might someday cite me as their source.

So... what's a teacher to do? Students will try to fit new knowledge into their preconceptions, even when the preconceptions are wrong. So it seems that de-bunking is necessary, especially for some fundamental ideas (geologic time, for instance). But is there any way to deal with misconceptions that doesn't reinforce them?

- Do students remember things better when they've figured them out for themselves? (Does the amount of time spent puzzling make a difference? Are projects that take up a large part of the semester more effective than a hands-on experiment during lecture? And what happens when the fundamental concepts are hard to directly observe, or when the evidence (such as S-waves traveling through the mantle) is difficult to understand?)

- Does it help to use lots of different senses/ways of learning about something? (Does it help to both hear and read, or to hear and read and see and do? Does it help to have touched a sample, or to have played a game, or acted out a process?)

- Is humor effective? Will students remember me snarking about the Giant Amethyst Geode of Death in The Core, for instance? Do students remember mockery? (I would imagine that it's better if I'm mocking someone else - say, Hollywood - rather than mocking a classmate.)

- They say that repetition is effective. So, out of all the way-too-many concepts we cover in Earth Systems Science, what should I repeat? (Geologic processes are slow - I say that many times in many different lectures. I mention certain minerals - quartz, for instance, and calcite - a lot. I've defined "igneous rocks" in about three different lectures already. So I do this a little. But are there other things, important misconceptions, that I should be hammering away at?)

On a related note, I've always told students to study their old quizzes and exams to help figure out what they don't understand. But maybe that's a problem, too - maybe students remember their incorrect answers even more when they use old quizzes to study.

And on another related note - I wonder if this psychological issue is part of the reason why new scientific theories take a while to take hold. (Why are Kuhn's scientific revolutions necessary? Why doesn't science proceed by baby steps?) And is there a lesson for teachers in something like the acceptance of plate tectonics? What was it, exactly, about that American Geophysical Union meeting in 1966 that convinced people? There was supposedly a session on sea-floor spreading that drew a standing-room-only crowd, a session with one talk after another supporting earlier work on magnetism of the ocean floor. Was it the quality of the data, or the volume of the data, or the repetition? Or was everyone at the meeting already prepared to be convinced?

Saturday, September 8, 2007

there's no place like...?

Sheril at The Intersection wrote today about all that moving that academics do:

While whisking off to the next exotic (or not so glamorous) locale is quite a romantic notion -- the thing is, somewhere along the way all this traveling makes home a confusing concept.

The post struck a chord with me. Like Sheril, I've lived in five different states (and all four time zones in the lower 48) - and that doesn't count the summers I spent doing field work in Alaska. I've thought, many times, that this sort of rootlessness is particularly odd for me. I was attracted to geology, at least in part, because it is rooted in a sense of place.

Modern geology is both local and global. Mapping is slow, dirty, work, and after long days working the same quadrangle, you develop a certain intimacy with the place. Not just with the particular question that brought you there – the best field geologists that I have known see much more than the information that they publish or record on their maps. They know the plants (and which ones hurt to sit on), and the behavior of the animals, and which direction the big storms come from. Great field geologists know how to read their rocks, too, and it’s worth considering their models – they usually have made observations beyond the obvious.

But at the same time, geology is global. Plate tectonics. The rocks that are beside one another were not always where they are now; they may have been on entirely different plates when they formed. How quickly they were brought to the surface may be the result of changing conditions at a plate boundary, or may have been caused by changing climate, caused perhaps by the orientation of a mountain chain hundreds of miles away.

And travel, and field work in many different environments, make it easier to see the many possible explanations for a single outcrop. Sometimes it takes a different perspective to turn the interpretation of an area on its head. (A jumble of rock in Vermont might look like a submarine landslide deposit... unless you’ve seen the mess of California’s Franciscan Formation. Then, suddenly, you see the place as the remnants of an old subduction zone, and old New England feels like a place where things happened once.)

When I headed out for my PhD, I wanted to travel as much as possible, but when I finished, I wanted roots. I wanted to be one of those geologists who knows every burrow under every rock in the field area, a little eccentric, perhaps, but fully at home. But I haven’t managed it. I’ve lived in too many places, moving from one academic job to another. Every place there’s a new stratigraphy to learn, new landforms, new rainfall patterns, new ecology. I’m not the guru of the landscape that I want to be. Even after seven years here, I still don’t know the name of the cactus that I accidentally sat on while explaining how to take strike and dip. I still don’t know which human stories are true, and which were made up by locals to make fun of tourists.

I still feel like a tourist myself – like I’ve been a tourist in every field area where I’ve worked. It’s got its advantages – there’s something to be said for being able to tell stories about different landscapes, different tectonic settings, different climates. But it would be nice to have a sense of home, as well.

Friday, September 7, 2007

sceptics after a scientific revolution: global warming and plate tectonics

I wish I could remember where I read this criticism of An Inconvenient Truth, but I don't, so I'll have to paraphrase it.

[Edit: yorrike commented with the reference I was thinking of: Geek Counterpoint, at, said:

Metaphor -- fit of South American & African coastlines, difficulties that plate tectonics / "continental drift" had in being accepted.

Comment: This is a really lousy choice of metaphor. The theory of "continental drift" had a tough fight being accepted because it took decades to find data that explained how it worked. Once the data was available, though, the scientific community came around very quickly.

The rest of the post will read weird now, but I'll leave it as it is.]

Near the beginning of the movie, Al Gore tells a story about an old science teacher he once had. According to the story, someone asked the teacher about the similarities of the coastlines of South America and Africa, and asked whether they could ever have fit together. The teacher said no.

The story was told as a lesson that scientists can change their minds. It's also used as a parallel to discussions of anthropogenic global warming, to suggest that a scientific revolution has already occurred. (Science historian Naomi Oreskes, who has studied both the development of plate tectonics and the debate over global warming, has made that point. There are links to her work at the end of the Stranger Fruit post.)

Anyway, I chuckled at the plate tectonics reference in An Inconvenient Truth, and found it pretty appropriate. But I read a comment recently that took issue with it.

The argument went that plate tectonics was accepted quickly, after the data to support the theory built up. There are still skeptics about global warming. So the parallel must be inappropriate.

But, well... I think that geologists have been telling the story of the development of plate tectonics a bit too well. Now, I'm too young to have been at that pivotal AGU meeting where the pieces are said to have fallen into place. But I'm not too young to have encountered skeptics, even decades after the theory was accepted. One of them retired from my current institution less than a decade ago; recent alums still want answers to his questions.

And he wasn't alone - in fact, some very prominent geoscientists, people whose data and ideas contributed to the development of plate tectonics, remained skeptical until their deaths.

I can't find anything online that says this, but none other than Maurice "Doc" Ewing, founder of the Lamont Geological Observatory, supposedly remained skeptical about plate tectonics until his death in 1974. And that's despite being responsible for the amazing exploration of the ocean floor that was responsible for the revolution. (I'm pretty sure that this story comes up at some point in Naomi Oreskes' book Plate Tectonics; if it doesn't, I've heard it repeated by Lamont alums.) That's right. Plate tectonics was developed using data collected by Doc Ewing's researchers, but Ewing himself never accepted it.

S. Warren Carey was a much more obvious skeptic. He worked on the problem of mid-ocean ridges soon after they were recognized, and he argued that they were the result of spreading of the ocean floor. That was an amazing contribution to the science, and he was awarded a GSA Structure/Tectonics Career Contribution Award in 2000 for that and other work. But he never believed that subduction occurred - he argued that the earth was expanding, and that subduction zones were actually zones of extension. (There are some pretty pesky focal mechanisms to explain, and there's the problem of how that magma gets to the surface.) He wrote about "diapiric krikogenesis" as an alternative explanation for arcs, as late as the 1980's.

Those two examples were people who did ground-breaking work in the field. I'm pretty sure there are others. The pioneers of plate tectonics are retiring now, and the skeptics are passing away, and the stories that we tell introductory students begin to seem like ancient history. So much like ancient history that students (and members of the general public) can't imagine a debate ever occurring. And now students and others look at things like the AAPG statement on climate change and think that it means that the science is not settled - that settled science means that there are no disagreements, no mutterings about this or that hole in the theory. But the continued existence of skeptics doesn't mean that. It just means that it's hard to change the minds of people who were taught the old stuff. That the continents are fixed. That the climate has always changed and therefore all climate change is natural.

On the morning of Halloween, GSA is having a symposium on the causes of global warming. The issue seems to have been settled at AGU for years. It will interesting to see whether the GSA symposium feels like settled science (and a discussion of policy alternatives), or whether the debate at GSA continues.

Tuesday, September 4, 2007

CUR Geosciences blog; Cutting Edge workshops announced

A couple announcements promoting groups involved with teaching geosciences and working with undergraduates:

The Council on Undergraduate Research Geosciences Division has a blog: It includes announcements of upcoming workshops and technical sessions.

(If you don't know CUR, they promote and encourage research at undergraduate institutions and research with undergraduates. The Geosciences Division sponsors the undergraduate research poster sessions at regional GSA meetings, technical/education sessions at national GSA and AGU meetings, and workshops on getting started in doing research with undergraduates. The workshops, in particular, are open to post-docs and grad students, and are especially useful to people who want to work at primarily undergraduate institutions.)

On the Cutting Edge (the NSF-sponsored series of workshops put on by the National Association of Geoscience Teachers) has announced their 2008 workshop schedule. There are workshops on preparing for an academic career that might be of interest to grad students and post-docs. There is also going to be a workshop on using visualizations, models, and online data - this might fit with the interests of some geo-bloggers (Brian? Maybe Ron?).

(I went to the Cutting Edge workshop on Teaching Structural Geology, and the pre-Cutting-Edge workshop on Teaching Mineralogy. I found both of them very valuable, partly for the teaching ideas and partly for the conversations and connections with people with similar interests.)

Sunday, September 2, 2007

reviewing articles: anonymity, or not?

Here's a question for all the readers of the geoblogosphere:

Under what circumstances would you choose to remain anonymous when reviewing a journal article?

- When recommending an article for rejection, or stopping just short of recommending rejection?
- When reviewing somebody famous/important in the field?
- When your personal circumstances were uncertain (grad student, post-doc, pre-tenure faculty member...)?
- When some other type of politics was involved, and you had somehow gotten stuck in it?

I have received anonymous reviews, back in the far distant past. They panned my papers, but stopped just short of recommending rejection. I was too stubborn (or maybe too stupid) to get the hint, and stuck with it until the papers were published. (Also, although the reviewers were anonymous, their identities were pretty obvious. They were the only people who would have had those particular objections. So I didn't feel like I had been personally rejected, or that my ideas weren't worthwhile - I felt like I had gotten stuck in the middle of an argument that I hadn't started.)

The signed reviews that I have received, on the other hand, were very constructive, and I learned some useful things by dealing with their comments. (I learned a lot from dealing with the anonymous reviews, as well, but I also learn from picking up hot objects off the stove.)

After my experience with anonymous reviews, I have always signed my own reviews. (Even when the reviews were very harsh, in part because I suspected that my identity would be obvious.) But I've also always gone out of my way to be constructive and detailed in my criticisms. And it's a good thing that I'm not asked to review papers very often, because critical-but-constructive reviews are a lot of work.

And I wonder. Is there any paper for which I wouldn't sign a review?

What about you?

of lakes and rocks (or why I do what I do)

I grew up on the second-most-polluted lake in the state of Maine. It was nasty – it looked like pea soup, and it smelled like rotting vegetables. But it was also beautiful – blue reflections from the sky, green trees hiding the houses on the other side, eerie cries of invisible loons in the evening and morning. There was a big rock, just right for sitting on, out where the water was about four feet deep. On the beach, there were shiny flat pebbles just right for skipping, and little sand grains that stayed stuck to my feet, even when they were dry.

The lake’s problem stemmed from years of being over-fertilized – sewage from two upstream towns was poorly treated, houses around the lake had leaky septic tanks, and rumor has it that there used to be a potato chip factory that dumped peels into the lake. By the 1970’s, it was a prime example of a eutrophic lake, a lake that had gone scummy and bog-like before its time because of too many nutrients and too much algae.

My dad started working on the lake’s problems in the early 1970’s. He’s a mathematician, and he worked with a geology grad student to develop a computer model of phosphorus cycling in the lake. I didn’t experience the modeling (well, other than scribbling on used punch cards), but I did get to help with the water sampling a few times. Mostly I sat in the boat and watched them collect bottles of water and lower a secchi disk until they couldn’t see it any more. But it made an impression on me. I remember bringing a little bottle of water and zooplankton for show-and-tell in 2nd grade. And by the time I was in high school, the research had turned into an experiment in cleaning up the lake. There were some new sewage treatment plants built (eventually – one town finally built its new one just a couple years ago), but the big experiment was the new dam. The town excavated the lake’s outlet and, every fall, lowered the lake by more than 10 feet, in hopes of flushing the phosphorus downstream.

I was impressed (though I didn’t think through the implications of sending the problem down to the Kennebec River and the Atlantic Ocean). I was impressed enough to have megalomaniac 10-year-old dreams of becoming a scientist and figuring out how to make chemical reactions run backward and solve the world’s pollution problems. (I hadn’t studied the 2nd law of thermodynamics then, obviously.)

When I went to college, I wanted to study environmental chemistry. But there was a freshman seminar offered on environmental geology, and intro chemistry wasn’t offered until winter term, so I took geology to have some fun and kill off my writing requirement.

And I got hooked.

Field trips. We walked along the river and talked about currents and sediment and erosion and floods. We went down to a park and made geologic maps of flat-lying sedimentary rock by coloring along contour lines. (Did I happen to mention that I went to college in the Midwest?) The horizontal bedding, actually was a huge revelation. I had grown up in a world full of glacial erratics and widely spaced outcrops that had no obvious relationship with one another. The idea that rocks could be correlated from one outcrop to another astounded me. And beyond that, rocks were laid down flat. I can hear the people laughing already when I say this, but the priniciple of original horizontality was probably the single biggest revelation of my introductory geology class. (Well, that and plate tectonics – I had taken an earth science class in high school, but the textbook was outdated, and even in 1981 I got the impression that continental drift was some wacko idea that had been mostly discredited.)

Our final project for the class was to write about the geology and landscape of my hometown. That was the first time I ever looked at the geologic map of Maine. I didn’t understand it, and wrote about the location of my hometown on a drainage divide between two major river systems. But when I went home for winter break, I started noticing the rocks. In particular, I noticed one road cut on I-95, just outside Bangor. It was made of phyllite, and it glistened even when it was dry. And the layering was vertical.

If rocks started with horizontal layering, and the rocks around Bangor had vertical layering, then... something really cool had happened there, practically in my backyard. And I wanted to know more about it.

Chemistry was pretty much doomed as far as I was concerned. I held on to dreams of being an environmental geochemist for years – I monitored water quality as part of a campus job, I applied to grad schools with low-temperature geochemistry programs, and I worked for the USGS on a project dealing with mitigation of acid mine drainage. (And I kept taking chemistry classes, though physical chemistry.) But the rocks kept calling. Not just any rocks. Rocks that had been through a lot and had stories to tell. Rocks that had been buried, contorted, heated, transformed. Rocks that were once under the equivalent of the Himalayas (120 million years ago, or 380 million years ago, or 1.7 billion years ago). Down a subduction zone. Stretched and thinned in a metamorphic core complex. Baked in the aureole of a pluton. Metamorphic rocks are the survivors of geology. They have been through it all, and it has changed them, but they haven’t melted or broken apart.

And I like to know their stories.

Oh, and the rocks on the beach where I grew up? The sand grains and skipping stones were phyllites, and the big rock in four feet of water was a granite boulder. There were pebbles with andalusite in them, too, probably from the aureole of one of the granites or another. So I may not be studying lake water, but my rocks still remind me of home.