About Geology

Geologic Photo Tips

2009-11-23T14:42:13Z

One of my favorite things is taking photos of geologic features. In 12 years of doing that and putting them online here, I've learned a few tricks and tips. This photo illustrates one of the best: get there during the morning or evening "golden hour" for the best light. Most of the other tips in this presentation are about coping when you can't do that.
_{Fort Rock, Oregon — Geology Guide photo}

Geologic Photo Tips originally appeared on About.com Geology on Monday, November 23rd, 2009 at 14:42:13.

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Student Scholarships Available

2009-11-20T02:11:47Z

At the last meeting of my local geological society, they announced that the deadline for our three scholarships, one undergraduate and two graduate, is being extended to December 15 to collect more candidates.

This money is meant for research in or near northern California (I guess that means all of California), but the student could be anywhere in the world, so this isn't a parochial thing. I have a larger point, though: if you're a student at any level, beat the bushes for money from your scientific and professional societies, not just the big agencies.

By the way, my society also makes awards to primary and secondary school geoscience teachers. Check its home page.

Student Scholarships Available originally appeared on About.com Geology on Friday, November 20th, 2009 at 02:11:47.

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Earthquake-Light Theory Update

2009-11-19T01:02:14Z

Last night I attended a presentation on the rock-physics based theory of earthquake precursors (the p-hole theory), and things are moving along nicely. Funders including the World Bank and institutions like the new SUSEL underground lab in South Dakota are supporting research projects. I confess to a bit of a chill as the speaker, Robert Dahlgren of UC Santa Cruz, got into the fringe subject of "earthquake clouds," but there are some intriguing satellite pictures and perhaps the time is right for some genuine ferment in the field of earthquake prediction. The whole theory is summarized in this article so I won't repeat it here, but seven presentations on the topic will be given at the big AGU meeting next month.

Earthquake Lights
EQ Lights and Mental Effects
Online Lecture by Theorist Friedemann Freund

Earthquake-Light Theory Update originally appeared on About.com Geology on Thursday, November 19th, 2009 at 01:02:14.

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The Threat from Kivu

2009-11-17T19:05:11Z

No, this isn't about a mysterious cosmic visitor that will cause the world to end in 2013. It's about Lake Kivu in Africa, a large rift-valley lake that straddles the Rwanda-Congo border. It is the world's third known erupting lake, after deadly lakes Nyos and Monoun in Cameroon which produced deadly choking clouds of carbon dioxide in the 1980s. Kivu has similar chemistry to these two remote crater lakes, but it has 2 million people living around it.

American researchers are organizing a scientific workshop in Rwanda to get local scientists involved in studying Lake Kivu. (See the press release from Rochester Institute of Technology.) With the right design and buy-in from the two nations sharing the lake, a solution might be found like the safety valves put in the two Cameroon lakes. Those are simply large pipes that allow the CO₂-charged deep water to rise and vent in a self-sustaining fountain. Unfortunately Kivu is thousands of times larger, and the lake gases include methane as well as CO₂. That means Kivu could explode in flames before smothering you, and it also means that methane is an attractive energy source. So much mixed news from an unmixed (meromictic) lake.

The Threat from Kivu originally appeared on About.com Geology on Tuesday, November 17th, 2009 at 19:05:11.

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A Comic Disaster, an Art Fossil

2009-11-17T00:23:18Z

I found two fun things yesterday. First is Mike Russell's CulturePulp online comic, where the latest entry is a spoof on geological disaster movies featuring "Lava Tornado!" Old fuddy-duddy that I am, I've written about the twisted ideas that moviemakers have about geologic hazards, but this guy has a deft touch and much better knowledge of film clichés. (More on geology and the movies plus some reader ideas)

On the mind-boggling side is the modest Triloblog, which features not trilobite fossils, but artists' sculptures, photos and drawings of trilobites. Andrew Scott is the site's owner and a wide-ranging fellow with no academic training, just the right sort of wonder about his subjects. Trilobites deserve that as well as the scientific attention.

A Comic Disaster, an Art Fossil originally appeared on About.com Geology on Tuesday, November 17th, 2009 at 00:23:18.

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A Better Idea of Cement

2009-11-16T17:10:37Z

We make more concrete than any other material, but the exact nature of cement—the calcium-silica-hydrate called C-S-H that holds concrete together—has always been mysterious. A research team at MIT cracked the mystery and reported how they did it in the September 7 National Academy of Sciences Proceedings.

When making concrete, powdered cement is slaked—water is added until the material can't take any more—and then allowed to set, forming C-S-H. The MIT researchers took an analogous approach in the computer, using three important bits of data. First they built a molecular model based on the mineral tobermorite (which matches the first datum: the ratio of calcium to silicon). Next they slightly polymerized the silica, linking some of its tetrahedra into pairs and chains (to satisfy the second datum, the degree of silica coordination as measured by nuclear magnetic resonance). Finally they took this framework and packed it with water molecules, one by one, using the impressively named grand canonical Monte Carlo technique, until the resulting material reached the right density (the third datum). The chemical formula for cement determined this way is (CaO)_1.65(SiO₂)(H₂O)_1.75.

They validated this calculated substance against several experimental measurements and gained some insight into why concrete works as well as it does. The mineral framework of C-S-H is not quite crystalline, but has a random element due to the polymerized silica, creating openings that allow extra water into the matrix. This glasslike property gives concrete its crucial degree of elasticity.

This work shows promise in giving us the same control over cement that we now have for metals. And the method itself is promising for other complex materials—in fact, it was used in 2006 to calculate the molecular structure of serpentine.

More:
About Cement and Concrete
Serpentine the Mineral

A Better Idea of Cement originally appeared on About.com Geology on Monday, November 16th, 2009 at 17:10:37.

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Thanks Chet and Maureen

2009-11-13T20:23:37Z

I was tracking down some of the history of erosion theories. Specifically, I wanted the sources behind the widely accepted theory that we live on a cold planet today because we have so many mountains. Mountains expose rock to the elements, and weathered rock releases nutrients to the sea, and life turns nutrients into buried carbon. We appear to have not just very low atmospheric CO₂ levels these days, but basically the lowest possible CO₂ levels. (As civilization is accustomed to that, it means that a rather small perturbation in CO₂ levels, in geologic terms, has a relatively great effect in human terms.)

The theory linking mountain uplift to the late Cenozoic ice ages was propounded by Maureen Raymo in the 1980s. I'm thanking her in this post because her Web site, www.moraymo.us, has a bunch of papers tracing the theory's development since then.

And I'm thanking her father, the writer Chet Raymo, for his wonderful blog at sciencemusings.com, treating science in a most humanist way. I've added it to my blogs list.

On erosion:
Not Your Grandfather's Erosion
Mass Wasting: Power Erosion
The Remarkable Tibetan Plateau

Thanks Chet and Maureen originally appeared on About.com Geology on Friday, November 13th, 2009 at 20:23:37.

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Geothermal: Just Add Water

2009-11-12T17:19:45Z

The usual variety of geothermal energy involves drilling into hot rocks and pumping up the steam or hot water there. But the greater potential lies in dry hot rock, because there's much more of that. If you drill into hot rock, though, you need a working fluid to carry the heat to your turbines. You need water. This story in today's Bend Bulletin is about such a dry-rock or "enhanced" geothermal project in southern Oregon. We tend to think that geothermal energy is free energy, but it does use resources, especially water, and in many places that is scarce. Regulators are keeping a close rein on the project's planned water use. (Thanks to @TimMerrick on Twitter for pointing the story out.)

More:
On Geothermal Energy
The Coso (Calif.) Geothermal Field

Geothermal: Just Add Water originally appeared on About.com Geology on Thursday, November 12th, 2009 at 17:19:45.

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How to Douse Lava

2009-11-11T20:35:07Z

While updating my article on Sicily's Mount Etna, I had occasion to read about the efforts in Iceland to stop lava flows with firehoses. That was in 1973, when the volcano Eldfell, on the island of Heimaey, sent a flow of lava toward the town of Vestmannaeyjar. Given a big enough hose and water pressure, pumping seawater on the active flow was quite effective in freezing it in its tracks. A single hose, scientists found, could cool an entire hectare because as the cooling lava cracked it allowed the water to penetrate in all directions. (The problem was getting equipment of the right caliber to the scene.)

Being scientists, they checked by drilling holes. "In the boreholes, the cooling extended down to depths of 13 to 15 m, after cold water had been poured on the lava for about two weeks. A hole was bored in an area which had not been cooled by water, and molten lava was encountered directly below the surface." The whole report is online from the U.S. Geological Survey.

Also:
Eternal Etna
About Volcanoes
About Volcanism
Drilling into Volcanoes

How to Douse Lava originally appeared on About.com Geology on Wednesday, November 11th, 2009 at 20:35:07.

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Toward Tsunami Shelters

2009-11-10T14:45:32Z

The coastline of the Pacific Northwest and northernmost California—the land also known as Cascadia—is prone to gigantic earthquake/tsunami combinations like the one that struck Sumatra in 2004. An engineer for the state of Oregon, Yumei Wang, wants every seaside town to have strong platforms on stout stilts where people can run when earthquakes strike. Many of these communities, she says, are too flat and congested for people to reach high ground in the few minutes they'll have between the shock and the wave.

Wang is talking to the town of Cannon Beach about constructing America's first tsunami evacuation building or TEB. Because tsunamis are rare events, these structures should also have an everyday use. Wang's idea is for Cannon Beach to use its building for a city hall. She made a presentation on the idea at the GSA meeting in October; the GSA also has a white paper with more detail.

More background:
The Great Cascadia Earthquake of 2xxx
About Tsunamis
The 10 Most Deadly Tsunamis in Each Ocean
The 2004 Sumatra Earthquake
_{Conceptual TEB design by Ecola Architects — image courtesy GSA}

Toward Tsunami Shelters originally appeared on About.com Geology on Tuesday, November 10th, 2009 at 14:45:32.

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