Anisotropic Reflections

My favorite geologic word: Anticlinorium

Jefferson C. Chang — Fri, 24 Jun 2011 14:20:32 +0000

I don’t think it’s as obscure as geophantasmogram, but it’s not something you often hear around these parts, e.g., Oklahoma. Come to think of it, tectonics and topography don’t get mentioned much in local conversations either… But, I digress.

So, what is an anticlinorium? A more common geologic term that first comes to mind is anticline — and, as you may have guessed — the two are related. An anticlinorium is a series of anticlines (and synclines), which have also been anticlined. Wait, I know what you’re thinking, “Did he just use anticline as a verb?” Yes. Yes, I did. It’s the best one-line explanation I can think of. Another way to explain an anticlinorium is that of a fold with at least two considerably different, dominant wavelengths [ahem]. Forgive me. Sometimes, I speak geophysics.

For the best explanation, I suggest looking at a cross-section:

Why is this my favorite geologic word? Because geologists are wordsmiths, a lot of the words I use are somewhat made up (cf., anticlined) — this one is one of the more geologically valid ones. If anyone is interested, I’m in search of the ever elusive monoclinorium… Let me know if you see it first!

For a list of other geologists’ favorite words, check out the Accretionary Wedge #35.

M2.4 Earthquake Carson, CA Seismic Array Visualization

Jefferson C. Chang — Tue, 14 Jun 2011 22:11:07 +0000

A M2.4 earthquake occurred in Carson, CA, on 2011 May 14 @ 14:19:00 UTC (2011 May 13 @ 21:19:00 local time), at a depth of 11km. Coincidentally, this earthquake was recorded by a high-density (100m) 3D seismic array in Long beach, CA. The data were recorded by NodalSeismic, and a resulting time-lapse generated by Dr. Rob Clayton of CalTech.

If you’re anxious, the good stuff starts at ~1:00. Enjoy!

Visualization of Groundmotion of the 11 Mar 2011 Japan Earthquake with USArray

Jefferson C. Chang — Fri, 11 Mar 2011 18:39:35 +0000

Courtesy of IRIS.edu

Visible shockwaves from Eyjafjallajökull eruption

Jefferson C. Chang — Thu, 22 Apr 2010 06:52:48 +0000

The shockwaves, passing through the clouds, were caused by the Eyjafjallajökull eruption on 18 April 2010. Verdict? Damn cool.

By the way, I have a dollar for the first person that teaches me how to say Eyjafjallajökull… properly.

The Ten Commandments of Geology

Jefferson C. Chang — Fri, 16 Apr 2010 03:30:10 +0000

Commandments 1-5: How to properly worship the only true Advisor

1. I am The Advisor your God, who brought you out of the land of bliss, out of the house of innocence. You shall have no other gods before Me.

2. You shall not make for yourself other commitments, or any likeness of anything that is time consuming, or that is in other professors’ interests, or that is assigned in your classes; you shall not bow down to them or serve them; for I The Advisor your God am a jealous professor, visiting the iniquity of the fathers upon the children to the third and the fourth generation of those who have had Me, but showing steadfast love to thousands of those who will not be advised by Me and keep My Commandments.

3. You shall not take The Name of The Advisor your God in vain; for The Advisor will not hold him guiltless who leaves His name from publications.

4. Remember the Sabbath day, to keep it occupied. Six days you shall labor, and do all your work; but the seventh day is a Sabbath to The Advisor your God; in it you shall work even more so, you, or your son, or your daughter, your manservant, or your maidservant, or your cattle, or the sojourner who is within your gates; for in six days The Advisor wrote theses and dissertations, assembled PowerPoint presentations, and all that is in them, and also worked the seventh day; therefore The Advisor cursed the Sabbath day and so shall you.

5. Honor your Advisor and committee members, that your days may be paid with the stipend which The Advisor your God gives you.

Commandments 6-10: How to live in misery during academia

6. You shall not have fun.

7. You shall not commit to activities not assigned to you.

8. You shall not sleep.

9. You shall not bear false citations within your thesis.

10. You shall not covet your officemate’s thesis, you shall not covet your officemate’s field area, or his funding, or his stipend, or his poster, or his van, or anything that is your officemate’s.

Sing us a song, you’re the geo man…

Jefferson C. Chang — Thu, 25 Mar 2010 09:00:49 +0000

As geologists, the nature of our work relies on seeing the rocks. Hence, our field day usually ends when the sun sets. After which, we are often huddled about the camp fire (most-likely, with beer in hand) recanting stories of past field seasons. Once in a while, someone will bring a guitar or radio out to the field, which (again, beer might be a contributing factor in this) presents an opportunity for musical high jinks. After much trial and error (and even more beer), the right words will coincide with the right tune, thus giving birth to the musical genre known as geology songs.

Dr. Richard Alley is a professor at Penn State, who happens to have a knack for weaving geology into popular songs – an example of his fine art can be seen above. I find his videos to be great mnemonic aides when teaching introductory geosciences. Check out his other videos on YouTube, like Ring of Fire.

Note: For implying that geologists always drink in the field, I would like to apologize to the 1% of geologists who do not consume alcohol.

Scientific Ink

Jefferson C. Chang — Tue, 16 Mar 2010 06:41:19 +0000

Photo from of SmilePanic.com

In honor of March 14th, why not remind yourself of the ratio of a circle’s circumference to its diameter. Perhaps maybe something more daring, like the wave equation – better yet, the Zoeppritz equations. As for me, I’ll hold out till I invent a new transform. Meanwhile, here are some folks who think that science makes for good tattoos.

Words to the wise: When doing scientific tattoos, double check the design and make sure at least one person is sober. A classmate from my undergraduate university tattooed a stratigraphic column of the Grand Canyon on his forearm. What does he have to show for it? A mythical Bright Angle Shale, beneath the Muav Limestone and above the Tapeats Sandstone.

Chilean Earthquake of 27 Feb 2010

Jefferson C. Chang — Thu, 11 Mar 2010 22:52:59 +0000

The rarity of large (Mw > 8.0) earthquakes makes it challenging for seismologists to study the dynamic processes that occur when faults fail. The Chilean Earthquake of 27 Feb 2010 is estimated to have a moment magnitude (Mw) of 8.8 – only 5 earthquakes are known to have been larger.

2010 Tsunami Map from Chilean Earthquake, courtesy of NOAA

Eric Kiser, over at Harvard, has done some preliminary modeling, which lets scientists get a glimpse of how the dynamic rupture might have occurred on 27 Feb 2010. There is an extremely nice animated GIF on his site that I dare not poach, and I recommend getting a higher resolution image of it.

How to make homemade lava

Jefferson C. Chang — Mon, 23 Nov 2009 22:02:41 +0000

Sample: Gabbro (solid cylinder)
Normal load: ~8 MPa
Velocity: 5 m/s

This is a preliminary test of the new High Velocity Rotary Friction Apparatus in Rome, at the High Pressure High Temperature Laboratory of Experimental Volcanology and Geophysics of INGV. The primary investigator for the project is Giulio Di Toro

I am involved in investigating earthquake parameters, also utilizing a rotational apparatus much like the one showed on the video. But, our runs are a bit more tame in comparison.

Oh, you Luciferian fool, you

Jefferson C. Chang — Tue, 10 Nov 2009 04:53:32 +0000

One of the geoblogs, Clastic Detritus, got an interesting comment from a rabid lunatic concerned reader. I would post a snippet of the response, but it would take away from the classy ensemble. Read it here.