Friday, September 25, 2009

Accretionary Wedge #21: Call for posts

The 20th edition of the Accretionary Wedge is up at Dave Bressan's cryology and co. There are some neat speculations about unsolved mysteries in geoscience - go check it out! (And even if you're a bit late, you can probably sneak another entry or two in there.)

Which brings us to the next topic of interest: October's Accretionary Wedge (#21), which will be hosted here. October is a big month for Earth science this year - not only is the Annual National GSA meeting happening in Portland from October 18-22, but it's also the month of Earth Science Week (October 11-17). In other words, it's a month for sharing knowledge about the Earth (something that we geobloggers do a lot).

A lot of our time revolves around professional and academic concerns, but it's a good idea not to forget the outreach - after all, if people who aren't our students or colleagues don't know why Earth science is important, where does that leave us? So here's your question for October:
What kind of Earth Science outreach have you participated in? Have you hosted a geology day at your department, given a field trip, gone to your child's/niece's/nephew's/cousin's school to do a demonstration, or sponsored an event for Earth Science Week? (This year's Earth Science Week is about Understanding Climate, so if you're a climate scientist, please chime in!) What was your favorite experience (or what funny stories came out of one that didn't go as planned)?
Since GSA is going to take up a big chunk of peoples' time, I'll set the due date for the weekend after the Portland meeting (Sunday, October 25th). If you're doing something for GSA or Earth Science Week, you should have plenty of time to write about it for the Accretionary Wedge - plus this edition of the Wedge gives you good incentive to plan something if you haven't already. (And, as always, if you're a little behind on your blogging, late entries will be added as they're received.)

Leave a link to your post in a comment or send it to me by email at magmacumlaude AT (replacing "AT" with @). Happy writing!

Sunday, September 20, 2009

Accretionary Wedge #20: Geologic discoveries for the future

David Bressan at cryology and co. posed this question for the latest edition of the Accretionary Wedge:

What remains to be discovered for future earth scientists what we (still) don't know about earth? What are the geological riddles that still lack answers - all questions are allowed - it could be a local anomaly, or a global phenomena, or something strange...(Naturally you can also include a possible answer to your problem).
One question I'd like to see answered in the future is something that many volcanologists have been (and are still) trying to figure out: What does the inside of a volcano really look like?

Early scientists thought that volcanoes were the homes of gods, or passages to Hell, or conduits for a vast network of subterranean fires. (At left is Athanasius Kirchner's 1664 engraving of the interior of Mount Vesuvius, from his book Mundus Subterraneus. Image from These ideas have all fallen by the wayside, but volcanologists today are still trying to work out the details of volcano 'plumbing', as it's commonly called.

This is no easy task. For one thing, there are many different kinds of volcano; it stands to reason that they're not going to have similar plumbing systems or structures. For another, if you're interested in what's going on inside an active volcano, it's understandably a little difficult to get close enough to the object in question to even begin to work on the question.

So how do volcanologists know anything at all about the interior of volcanoes - and how can they find out more?

One of the easiest ways is to look for volcanoes that are no longer active, and have been worn down by time and erosive forces. There are actually some great examples of these: The Summer Coon volcano in southern Colorado, which shows a spectacular radial pattern of dikes (see the Google Earth image at right); the cinder cones in the Southwestern Nevada Volcanic Field, which one of my professors studies (Keating et al., 2008); even my own study area, at the Santa Maria volcano in Guatemala, has a spectacular view of the internal structure of a stratovolcano (revealed by the 1902 eruption that blew a huge crater in the side of the mountain).

Another way is to use geophysical or remote sensing methods. Volcano seismology (including 3D seismic tomography, sort of a CAT-scan for volcanoes) has been used for years to locate and define the shapes of magma chambers under volcanoes, as well as the dikes and conduits which feed eruptions. For smaller edifices, methods such as ground-penetrating radar can give some idea of the shallow structure. Some researchers in Japan (Miyamachi et al., 1987) have even used explosions from fireworks to image the interior of lava domes (using the shock of the fireworks explosions to take the place of seismic shocks). GPS, ground tilt, and other deformation measurements give volcanologists an idea of how a volcano changes shape and volume, and from that some idea of the internal workings of the volcano can be discerned.

One interesting study by researchers in Japan (Sakuma et al., 2008) details a project where volcanologists actually drilled into an active volcano - Mount Unzen, which last erupted in 1996 and produced a summit lava dome. The Japanese volcanologists found a conduit with several feeder dikes, showing that Unzen's eruption wasn't fed by a single tube but several, and possibly from many sources. Still, this is only a small part of the volcano, and it's a very expensive and tricky way of finding things out.

Because of these methods, we know something about the interior of volcanoes. For example, the old chamber-conduit-summit eruption model for stratovolcanoes is, we now know, an extremely simplistic and not entirely correct view; many stratovolcanoes are riddled with dikes and smaller pockets of magma and other interesting things like cryptodomes. And they're hardly ever as nicely layered as this image suggests. (From the USGS Eastern Geographic Science Center Volcanoes! teacher resource.)

But we've still got a long way to go. You can't just X-ray a volcano, and it's very difficult to image an entire mountain with other methods, especially if it's in a remote area, large, and (as they tend to do), erupting. Knowing the plumbing of a volcano is, however, important for forecasting how the volcano will behave: Will it erupt vertically or laterally? Is the magma chamber shallow or deep, large or small, and is there more than one? Could there be outbreaks of lava on the flanks as well as the summit? Is the volcano structurally stable or collapsing? Does it contain a pressurized cryptodome that could explode, or lava that will ooze out of vents? These are all questions that depend on what we can find out about a volcano's insides, and that's something that volcanologists are always working on.

And hey, maybe I'm being pessimistic and someone will invent a whole-body-scan for a volcano. It could happen...

Additional reading:

Keating, G.N. et al., 2008, Shallow plumbing systems for small-volume basaltic volcanoes. Bulletin of Volcanology, v. 70, p. 563-582.

Miyamachi, H. et al., 1987, Seismic experiments on Showa-Shinzan lava dome using firework shots. Pure and Applied Geophysics, v. 125, no. 6, p. 1025-1037.

Poland, M.P. et al., 2004, Patterns of magma flow in segmented silicic dikes at Summer Coon Voclano,Colorado; AMS and thin section analysis. Earth and Planetary Science Letters, v. 219, p. 155-169.

Sakuma, S. et al., 2008, Drilling and logging results of USDP-4; penetration into the volcanic conduit of Unzenvolcano, Japan. Journal of Volcanology and Geothermal Research, v. 175, p. 1-12.

Thursday, September 10, 2009

Speaking well

I won't touch on the political parts of the President's speech Wednesday night (or the fallout from adults not being able to behave like adults, on both sides), but I do want to write about the way in which it was delivered.

Public speaking is a big part of being a geologist, whether you're talking to a lab section, lecturing to a class full of hundreds of people, or giving a talk at a conference. One of the things that my professors and other mentors have stressed, many times, is the importance of speaking well - and that doesn't just mean being able to intelligently discuss your subject material, it means making it interesting. I could be talking about a volcanic eruption, which is one of the most flashy and exciting processes that goes on in geology, but if I gave the talk in a boring way, it would leach all the excitement right out of it.

Because I think President Obama's address was an excellent example of rhetoric, I'm going to use him as a guide to good speaking techniques. (NOTE: This doesn't necessarily mean that I remember and use all of these techniques when I'm speaking - I still get nervous during class presentations, and I have a number of bad habits I could get rid of. But I know what I can work on, and these are good examples of those things.) You can bring up videos of Obama's recent health care speech to see what I'm talking about, as well as videos of the other people I mention.
  • PRACTICE: This is the single most important thing you can do before giving a talk. You can bet that every single president has had speech coaches at one point or another, and that no one goes out and delivers a State of the Union address, for example, without having gone over it a few dozen times. President Obama probably practices enough to memorize most of his speeches, since he doesn't spend much time looking at his notes or a teleprompter. Since that's not always possible for someone giving a lecture to a class or presenting a class project, for example, at least make sure you know how your talk progresses - memorize the main points you want to get to, make notecards to remind you, and deliver the talk to your friends, parents, pets, potted plants, walls, etc. The more comfortable you are with your subject matter, the better your talk will be.
  • Posture: This is your stage dressing. If you slouch or hunch or turn away from your audience or stiffen up during a speech, they'll read your body language and deduce that you're not happy or comfortable or interested in the material. If it's not worth your time, why is it worth theirs? President Obama is very good at standing straight but not looking uncomfortable about it; he also turns and moves a little to keep from seeming glued in place. (The more recent former President Bush was all right at this, but he also tended to cling to the lectern during his speeches, so he came across as stiff and uncomfortable.) It's not good to take this too far and start rocking back and forth, though; that's just as annoying.
  • Hand motions: These are really important for underscoring your speech. Hand motions can put emphasis on a point or help your words flow. Combined with your tone of voice and volume, they can make something really memorable, or indicate that one part of the speech is important but not the main point. President Obama is great at using hand motions, and it makes his speeches very emphatic. On the other hand, one reason that former President Nixon is so painful to watch is that he has terrible timing, and his gestures don't match what he's saying. It's like watching someone else control his body. Also, if you're not comfortable using your hands, don't cling to the lectern or wave the laser pointer too much or bang your pointing stick on the floor (or your feet). I've seen people do all of these things, and they're awkward and distracting.
  • Eye contact: This is a trick they taught us at our TA training - pick a person in the audience and look at them for a little while. Make your audience feel like you're addressing them and not just the back wall. I'm pretty sure the President does this, because he's shifting his eyes around the room when he talks, and he's not staring at the teleprompter or his notes. Probably most of us still need notes for a long lecture, and don't have teleprompters, but it's a good idea to look up at your audience more often than you look down.
  • Tone & volume: Talk loudly enough to be heard, but modify your tone as appropriate, and don't talk in a monotone (remember Ben Stein? Audiences hate that). Be a little louder and more emphatic when you're making an important point, and pull back a little when you want the words to flow. Singers do this; it's the reason they get louder or softer, choppy or smooth, to give the appropriate emphasis to the lyrics they're singing. You don't want to trail off into mumbling or speak like a robot, because it gives the impression that you don't think it's important; modulating tone and volume keeps the audience interested.
  • Enunciation: Nothing is worse than a mumbling speaker. If your audience can't understand you, they'll stop paying attention. In addition, make sure you're pronouncing words correctly - it makes you look bad when you mispronounce a word, and it's easy to get an incorrect pronunciation into your head. Look it up beforehand; use or a colleague. (I absolutely hate it when people say nuclear "nuke-u-lar", for example. This is not a dialect or an accent thing; it's just wrong.) President Obama speaks very clearly and loudly, and I suspect that he could have given his speech without microphones and everyone would have heard it just fine.
  • Stalling tactics: Saying "um" a lot erodes your poise and is, frankly, painful for the audience. Stalling words ("um", "ah", etc.) are sometimes necessary, though, especially if you're thinking about the answer to a question (because most people don't speak how they write). If you must pause or stall, think of other ways to do it, and work on getting comfortable enough that you don't do it (in speeches or lectures, at least). Rephrase the question or make an easy comment before going on to your answer. Presidents giving speeches usually have teleprompters and can avoid this, but stalling techniques come out when they have to answer questions at press conferences (this is true for pretty much everyone, including President Obama). Also, "like" isn't an acceptable stalling word ever. It's really immature and older listeners find it annoying (and grammatically incorrect, to boot.)
It's not easy to remember all of these, of course, but the best speakers try to incorporate at least a few things (with practice being the most important one). Someday I hope I can be as good a speaker as the people who've taught me, and in the meantime I'll keep on working these tricks and techniques into my class presentations, conference talks, and anywhere else I can.

Tuesday, September 8, 2009

Lodging for GSA

I'm in a bit of a fix - it turns out that most people in my department have friends they are staying with in Portland, and no one is booking hotel rooms. Being Portland-friendless myself, I'm looking at a big hotel bill for renting a room of my own, unless I can find someone willing to share one with me.

Would any geobloggers be up for this? I'll be there Sunday for a short course and probably will be leaving on Wednesday. I'm pretty easy to live with and don't mind waking up early (in case people have talks to prepare for). I'd rather not use the GSA message board if I can stay with someone I know (even if it's through the internets). I'd also prefer a female roommate to avoid awkwardness.

Please contact me through the blog email if you're interested!