Video Friday

Still waiting to hear on some info for the next Santiaguito Observatory post, but in the meantime, here's a neat video to keep your attention: A view of an eruption filmed with a Forward-Looking-Infrared, or FLIR camera. (These are the cameras that you sometimes see on ghost-hunting shows when they're trying to find "cold spots", or what you might use to look for heat leaks if you're evaluating your house for heating efficiency.) Enjoy - espectially BHC, who requested it!

This is a "double" eruption of ash and gas filmed in March of 2009 from the Santiaguito Observatory. The FLIR video converter has sped it up for some reason, so it's about 12 times faster than the actual eruption, but you can always pause it and advance it slowly if you'd like to get the full effect. In FLIR video, the warmer colors (white, yellow, and orange) indicate higher temperatures, and the cooler ones lower temperatures. The highest temperature in this video is about 150C (although this can vary due to atmospheric and distance effects, so it's not an exact temperature). 

(Sorry for the poor resolution - Blogger's video tool has gotten worse, for some reason.)

Using Google Earth to visualize volcanic and seismic activity

I haven't been posting much lately (teaching labs and trying to wrap my head around volcano seismology is eating up my free time), but I have been trying to keep up with new developments. One really neat one is the release of the newest Google Earth and the Oceans layer. My last two labs have been oceanography and waves/tides/currents, so I've been leaning heavily on Google Earth to help my students visualize things. And it works! They're actually engaged, especially since they get to navigate around instead of just watching me give a lecture.

The Oceans layer comes with a lot of other sublayers, including one from National Geographic about plate tectonics, earthquakes and volcanoes. Being a geology geek, I already have several volcano/earthquake layers from the Smithsonian, USGS, etc. So, I thought it might be interesting to compare the old and new offerings.

Here's the first - the Smithsonian Global Volcanism Program's catalog of Holocene volcanoes.

I like this layer because clicking on a volcano pops up the text of the GVP webpage on that volcano, complete with photo and links. What I don't like about the layer is that this is all it does - nothing about plate tectonics, nothing about older volcanoes. You can see where the volcanoes are, but not (at first glance) why. Also, I'd opt for a snazzier symbol; that little X-and-box thing is efficient, but kind of boring.

Then there's the USGS layers for earthquakes. (They don't seem to have a volcanoes layer, but they do have an interactive map of recent activity here). One EQ layer shows earthquakes by age (i.e., in the past hour, day, week, etc.), and the other by depth. I like the clean look of these, the small legend, and the information that pops up for each earthquake, complete with links to the USGS online record and

The most recent earthquakes are shown in red (hours ago), days-old earthquakes in orange, and months-old earthquakes in yellow.

Here the shallower earthquakes are in red and orange, and the deepest are in blues and purples.

I like these because the symbols are easy to read, the legend is simple, and there's information about tectonic plate motions (including rates of movement) and boundary locations. The layers also updates themselves each time you open up Google Earth - very useful if you're teaching a class on plate tectonics, and want your students to keep track of earthquake activity in a particular area. You can even highlight specific types of plate boundaries, which are have their own separate sublayers.

The USGS has one more layer of historical earthquakes, with M3 in the past 90 days, M4 in the past year, and so on up to M9 (since 1970 - only one of these, the 2004 Sumatra earthquake).

No legend or drawn-out plate boundaries on this one, but a wealth of information and popups for each earthquake. It's especially good for highlighting plate boundaries using seismic activity.

Finally there's the new National Geographic plate tectonics layer. They went all out on this one - sublayers for plate boundaries, volcanoes, hot spots, earthquakes, plate motions...the whole shebang. It's actually quite crowded at first. Unfortunately, to download it you have to turn on the main National Geographic sublayer of the Oceans layer, search for the NG symbol in the middle of the Pacific Ocean, and click to download the plate tectonics bit. This is a major drawback for the NG information, and in the future I hope they list their information somewhere instead of making you hunt for it on the globe.

One thing that I severely dislike about this layer is the legend. It's far too large and covers up a significant chunk of the globe. It's not adjustable, either, so unless you immediately memorize all the symbology, you have to keep turning it on and off. The sheer volume of information shown is also distracting - it's better to break it down.

This one shows the plate boundary locations and types, and relative plate motions. Unlike the USGS layer, however, there's no information about rates of movement.

This view shows some of the "Selected Hot Spots". I'm a little iffy on whether all of the locations this layer shows are properly considered hot spots - there's a lot of argument about these phenomena anyway. The bad thing about this layer is that beside displaying the names, there's no pop-up info about these locations, nor is there any explanation of what a hot spot is.

This view is showing the "Notable earthquakes since 1900" and "Quakes since 1900 greater than 6.5 magnitude" layers. Again, no information about the individual events, other than marking their location. I suppose it's useful for highlighting areas of high seismic activity, but it would be much better if there were at least magnitudes and dates listed for each event, so someone could look them up elsewhere.

And, finally, the volcanoes - small triangles are Holocene eruptions, and large ones are eruptions since 1900. Yet again, there's no further information - this is where the Smithsonian layer outstrips the National Geographic one, despite its simplicity.

So what's the final verdict? Use all of them! I'd reserve the National Geographic layers for general overview - showing the locations of plate boundaries, eruptions and earthquakes, for example - but use the USGS and Smithsonian layers for more in-depth examinations. The USGS layer is especially good for teaching seismology and plate tectonics, since it gives information on plate motions and individual seismic events - and links it all to the USGS database.

I'm looking forward to reviewing new layers as I find them, and hopefully I'll get a chance to use them in my teaching.

Blow it out your tailpipe. No, really.

The BBC website has just run a story about a car that runs on compressed air. This is an pretty cool vehicle, if the article is anything to go by:

[The car] "will be driven by compressed air stored in carbon-fibre tanks built into the chassis. The tanks can be filled with air from a compressor in just three minutes - much quicker than a battery car. Alternatively, it can be plugged into the mains for four hours and an on-board compressor will do the job.

"For long journeys the compressed air driving the pistons can be boosted by a fuel burner which heats the air so it expands and increases the pressure on the pistons. The burner will use all kinds of liquid fuel.

"The designers say on long journeys the car will do the equivalent of 120mpg. In town, running on air, it will be cheaper than that."

The company's website, Air Car Factories, is a little vague on the specifics of the cars, but it does give a brief history of compressed-air vehicles, including 19th century pneumatic locamotives and a 1930s car. There's also a form to fill out for more information and to be allowed first crack at purchasing a car. Unfortunately for people in the US who are interested, the only firm licensed to sell the car is limited to India, but the designer, Guy Negre, "hopes to persuade hundreds of investors to set up their own factories, making the car from 80% locally-sourced materials."

The idea is certainly intriguing. Who wouldn't want a car that produces no emissions and can be filled up using the tire pump at a gas station? A few dollars for a couple of minutes to fill up an air tank is a lot cheaper than $40 or $50 for a tank of gas, after all. There are, of course, disadvantages. Wikipedia has a list of them, including some major concerns with efficiency compared to electric motors and the fact that it still takes energy to compress air in the first place. The current air tank technology is also still in need of improvement, and for anyone in a cold climate, you're currently out of luck - since the engine doesn't create heat, you'll need a seperate heat pump if you want to keep warm.

I won't be trading in my current car for one of these just yet, even though I'd love to have something more environmentally-friendly. (I also think the Air Car is pretty unattractive, not to mention the tiny little tires would be difficult to replace if you got a flat.) But the technology, if it can be made more efficient, certainly merits attention.