Accretionary Wedge #26: The Evolution of Geoblogs

This topic interests me because I’m very interested in how the collection, storage and dissemination of information has changed in less than two decades.

Douglas Adams gave a talk at a tech conference in Cambridge in 1998 (audio - transcript, in which he described the leaps in human knowledge in terms of the Four Ages of Sand (perhaps appropriate as Michael is co-hosting this month): The first two ages were the development of lenses for telescopes and then microscopes, allowing us to experience the universe at increasingly larger and smaller scales; the third was the invention of the silicon chip, allowing us to do calculations fast and therefore make increasingly complex models of reality; and the fourth is the use of computer technology to expand our notion of communication -- beyond the one-to-one version (dialog, either in person or by letter or phone) and the one-to-many version (books and newspapers, then radio and television) we’ve had for the last century -- into the present-day cacophony of many-to-many communication. Many-to-many communication allows individuals to interact with the world in something approximating real time.

I love the Ages of Sand metaphor, not just because it is geological, but because lodged into it is the idea that carbon-based lifeforms who have evolved on a mostly silicon-based planet have learned to exploit this common element in its oxide and elemental forms to exponentially enhance both our vision (ages 1 and 2) and our capacity to collect, process, store, and disseminate information (ages 3 and 4). We’re on the way to being a global, silicon-based organism.

We’re beginning to see some of the effects of many-to-many communication: a recent positive example is the success of the Green movement in Iran last year in getting their story heard by the rest of the world. A dozen or so years ago a dictatorship could shut down the news spigot pretty easily -- iconic images of Tank Man taken in Beijing during the 1989 pro-democracy demonstration exist because the events took place in front of the Beijing Hotel, where several photojournalists were staying, and they were able to smuggle film out (today that scene would have been recorded on dozens of individual mobile-phone cameras and seen world-wide within hours).

My first experience with a computer was writing the final report for my junior field geology class on my housemate’s Mac SE, in 1989. When I arrived at Santa Cruz for grad school students had pretty broad access to the campus dial-up network (No T1 lines in campus housing until 93-94), and we were downloading the Mosaic browser by the fall of 1993. My first reaction was that it was just Usenet with pictures, but back in 1989 I never figured the producers of the Simpsons would be able to generate enough stories to keep the show going for a year.

I first came across the geoblogosphere quite accidentally in April 2007 when a routine search for information on textbooks brought me to a post from Ron Schott, proposing a GeoWiki. It took me a month or so to discover and decipher GoogleReader -- today I’m subscribed to 60+ geoblogs and read pretty much every post. This organic community of geology-types, self-selected for relative tech-savviness, works for me on several different levels:

1. Education
A non-trivial number of geoblogospherians/geoblogospherlings are educators. Some are at two-year institutions, some at small colleges and universities, and some are grad students and undergrads (and a number have transitioned in the last few years). Like many of you, I had to go through a re-education process in order to teach classes of beginning students, at least partly because my understanding of the general curriculum was much deeper in some areas than in others. Discussing these issues with other educators (particularly those whose strong areas have complemented my weaker ones) has been a big help for me.

2. Community
What I miss most about being at a research institution is having day-to-day contact with friends and colleagues working in geosciences. I attend GSA and AGU most years, both to see old friends and to immerse myself in current topics. Geoblogger meetings are a new addition to this (and of course we now have Geotweeters as well!), but the geoscience folder on Reader and my Twitter account expose me daily to an informal discussion of the current state of research, issues in education and industry, real-time information on eruptions, earthquakes, mass movements, floods, and photos of what people are having for dinner.

3. News/context
Without the geoblogosphere we would still know about the Haiti earthquake, the Indonesian tsunami, the eruption of Eyjafjallajokull, and the Gulf oil volcano, but global events like these must be either catastrophic or affect Americans or Europeans to become "news" here. Sites like Geology News and Eruptions provide information and context to events that often disappear down the global news hole. And the level of expertise out there provides me with background that is quite useful when I interact with friends and students. A current example can be found in Dave Petley’s coverage of the Attabad landslide -- I’ve never been to the Hunza valley but Dave’s coverage has made this as real a geological (and teachable) event as it could be from 12,000 kilometers away.

4. Activism
Last year Kim at All My Faults was a prime mover in promoting the highly successful Donors Choose/Giving Kids the Earth program. This week Jessica at Tuff Cookie is promoting the International Volcano Monitoring Fund (please give, if only to spite Bobby Jindal). Out here in the west, the big (non-budget related) story has been the attempt to strip serpentine of its designation as California’s state rock. Among those trying to make sure that politicians make decisions based on solid science are Garry Hayes, Andrew Alden, Brian Romans (also @perrykid and @cbdawson in the twitterverse). It remains to be seen whether we win this, but this previously ignored bill is now drawing attention of major media outlets across the state as well as inside and outside the country, and supporting editorials in major newspapers.

A common refrain is that the computer and the internets are just tools -- perhaps, but in the same way that the wheel and pencil and steam engine are tools, not the way potato peelers and thigh masters are tools. Some tools change the world and the way we function in it and the way we think. Clay Shirky compares the invention of the printing press with the advent of online publishing. The former democratized the dissemination of information, and led to increasing rates of literacy and education but that wasn’t the intent. The rapid spread of literacy and individual access to the printed word that played a big role in creating our modern world from that ancient one is an emergent property of movable type -- what we are part of today seems to be a similar revolution and it is worth watching closely as it advances through the culture.

But keep in mind, I’m the one who didn’t think the Simpsons would last...

In praise of green rocks

I've been following the hoopla/outrage over the California state legislature's latest intrusion into the byzantine world of state symbols for the past month, but have been reticent to dip my toes into the metaphorical waters -- I still feel bruised and abused over the battle between my beloved banana slug and the evil abalone for official state mollusk -- a battle that never so much ended as it dragged on into a stalemate, much like the Korean war (shut up, this is a great simile -- did you know that abalones are big supporters of Kim Jong Il?)...

Anyway, like Garry I have begun to compose a letter to the relevant assembly committees, members, and governators. I will print this out in multiple copies that will be sent out by snail mail, as my understanding is that no one pays more attention to your opinions than when you kill trees to express them (well, unless you give them lots of money).

For those who still read my rare ramblings, I'm interested in your input before I put this to bed. Some of the points have been made previously in this thread, though the only material I consciously cribbed was Chuck's points about talc formation and carbon sequestration:
__________________________________________________________________

Governor Schwarzenegger and Members of the Assembly and the Senate:

The California Legislature is currently considering a bill (Senate Bill 624) that would strip serpentine of its designation as the state rock of California, while declaring it to represent a hazard to the health of the state’s residents. I am writing to express my strong disagreement with this bill, and my dismay with some of the misguided or misleading arguments in support it. I am a graduate of both UC Berkeley and UC Santa Cruz, a professor of Geology at Saddleback College, and a member of the National Association of Geoscience Teachers, The Geological Society of America, and the American Geophysical Union, and while this letter represents my informed opinion as a scientist and educator, it does not necessarily represent the opinions of these institutions.

The rock serpentine (or serpentinite, the accepted geologic term for the rock) is commonly associated with the convergence of tectonic plates. It is formed from shallow mantle rocks (called “ultramafic” rocks) that have been altered by high-temperature fluids and then squeezed between two plates at (relatively) low temperatures. Outcrops of the rock are commonly pushed to the Earth’s surface along fault zones.

In California serpentinite is most common in the metamorphic belts of the Coast Ranges and in the Sierra Nevada foothills. The formation of serpentinite in our state is associated with the subduction of the Farallon Plate beneath the North American Plate beginning in the Mesozoic era and continuing until plate was completely consumed and the San Andreas Fault became active about 30 million years ago. Though it is found in many places in the world, the processes that brought it to the surface here have not occurred commonly so its abundance here is unique.

In the presence of water and CO₂ serpentinite can produce the soft slippery mineral talc, the primary component of talcum powder. This reaction has been proposed as a hypothesis to explain why some major and minor faults or fault segments in California move gradually and do not produce large earthquakes. Its ability to absorb carbon dioxide makes serpentine one of the more promising geo-engineering sinks for this rising atmospheric gas.

The yellow-green to blue-green color commonly found in the serpentine minerals antigorite and lizardite, along with the polishing of the rock through movement along fault lines, produces beautiful exposures of jade-like rock in many areas. Serpentinite is a common decorative stone, used in countertops and tiles, and was a common choice, along with white marble, for columns and sculpture by Roman artists and architects.

The soils produced by the weathering of serpentinite lack certain elements (calcium, nitrogen, potassium, phosphorus) necessary for most plants, and are abundant in others (chrome, nickel, and selenium) that are poisonous to most plants. The process of evolution has led to unique plant communities found nowhere else but California. Trees such as the Jeffrey Pine and shrubs such as the Manzanita thrive on these soils. Because they have evolved to absorb heavy metals some of these plants have been used in the process of bioremediation.

The analysis of SB 624 “declares that serpentine contains the deadly mineral chrysotile asbestos and that exposure to it increases the risk of the cancer mesothelioma,” and “declares that California should not designate serpentine as the state rock due to its known toxic health effects.” Serpentinite is not a poisonous rock, at least not in the sense that exposure to natural outcrops of the rock represent a danger.

Rocks are agglomerations of several minerals, and though serpentinite is mostly made of antigorite and lizardite, chrysotile is another serpentine-group mineral that is sometimes present. Chrysotile is an “asbestiform” mineral, meaning that it grows crystals that are fibrous (i.e., thin and flexible). It shares this form and designation with several different minerals in the amphibole group, including amosite and crocidolite (neither of which is associated with serpentinite). Note here that the term “asbestos” refers not to a specific mineral or rock but to a particular crystal form that a few minerals take.

While the inhalation of any ground-up rock dust (i.e., silica or coal dust) is dangerous, because of their fibrous nature exposure to asbestos minerals can present significant health problems. Long-term exposure to asbestos minerals in the extraction or processing industries has been shown to represent a health hazard, the strongest correlations are associated with exposure to the amphibole group minerals; though most asbestos formerly used in construction was of the chrysotile variety, correlation between cancer and exposure specifically to chrysotile is not nearly as strong.

Let me emphasize here that I am not suggesting that asbestos exposure is not a health hazard nor am I suggesting that lung cancer and mesothelioma are not serious health problems that the state should concern itself with. These dangers to public health are established, and state law already deals with exposure to these materials.

My primary concern here is that this legislation expands that declaration to include not just industrial exposure to airborne chrysotile fibers but to casual exposure to unbroken bulk samples or outcrops of serpentinite itself (would I still be allowed to have hand samples of serpentinite in my classroom, or to pass them around to students in my lab?). It would be as if the state were to declare granite to be hazardous because it contains trace amounts of radioactive elements, or to eliminate the California Poppy as the official state flower (and to declare it represents a hazard) because it contains alkaloids related to opium and morphine.

Many citizens feel that the designation of an official state rock, mineral, flower, song, vertebrate or invertebrate fossil, etc., is a frivolous exercise with which state government should not concern itself. State Government has an important role, however, in promoting the appreciation of the state’s historical, cultural and natural attributes. For California educators our park system, our museums, and the acknowledgment of state symbols, whether it is the state rock, the state flower, the state motto, or the grizzly bear on the state flag (the state animal), provide a jumping-off point for the discussion of the geological, biological, and cultural wonderland in which we are privileged to live and work.

Sincerely,

James L. Repka

Professor of Earth and Ocean Sciences

Accretionary Wedge: Geo-image Bonanza!

I've chosen to share an image (okay, several images and a video) from the field locale for my dissertation, an area already familiar to many geobloggers.

38° 24' 14"N; 110° 56' 15"W; bearing 200°

After sorting through several images from this set, I've chosen this picture taken from the eastern peninsula of North Caineville Mesa, just east of Capitol Reef National Park in southern Utah. We're looking south toward the Fremont River floodplain (green) and South Caineville Mesa (opposite the river). The Henry Mountains are just out of frame to the east, and the horizon slopes upward to the west into the Aquarius Plateau. The pediment in the foreground is an inverted stream channel filled with sand and boulders from the cliffs. The photo below, taken from the floor of the badlands, looks in the opposite direction toward the mesa .

38° 23' 53"N; 110° 55' 18"W; bearing 330°

The Cretaceous Mancos shale dominates the images here. The mesas are topped by the Muley Canyon (formerly misnamed Emery) sandstone member, overlying the Blue Gate shale that forms the badlands. The Blue Gate member represents an interior sea and is rich in bentonite -- I've done some unintended camping here when caught in late summer storms, and spent the better part of a morning excavating Blue Gate shale from the wheel wells of our field van. Its usefulness in lining water wells, as an absorbing agent, and in drilling mud becomes obvious when you've seen a half-inch of wet, swollen clay separate a six inch puddle of rain water from bone-dry clay below.

I'm told it contains shark teeth, oysters, ammonites and even mosasaurs, but I spent 6 weeks a year working here for 4 years and never came across so much as a snail (of course the first time I brought students into the area one of them found one of the most beautiful ammonites I've come across in the field).

I came out here with my adviser, Bob Anderson, intending to look at incision rates in the badlands by doing cosmogenic exposure dating of the sandstone caps on the badland ridges and hoodoos, but the project eventually moved out of the badlands and onto the strath terraces along the Fremont River and an attempt to correlate terrace formation with climate cycles (again using cosmogenic radionuclides). My colleague Greg Hancock did a big portion of his thesis looking at incision processes on these badlands channels, including installing acoustic sensors to detect the rare flow events:

38° 23' 18"N; 110° 55' 52"W

I was going to leave you with this photo of Factory Butte, with the Waterpocket fold in the background but I remembered this clip from the dailies of the never-completed movie "Dark Blood," a scene shot several days before the death of River Phoenix...

38° 23' 24"N; 110° 54' 45"W

How big was that one?

Every semester I spend time explaining the methods of measuring earthquakes to students. I explain magnitude, with a primer on how logarithms work. I talk about the limitations of the Richter scale in measuring larger quakes, as more energy is released at low frequencies, and how the Seismic Moment, though more difficult to calculate, provides a better snapshot of the released energy.

I always emphasize that intensity, as represented by surface wave amplitudes, frequencies and ground acceleration, is a more useful way to describe how earthquakes affect communities. Magnitude has the advantage though, in that it can be reported as a single number. This creates a problem in the way the general public perceives earthquakes, a problem addressed in this post I came across a few days ago.

The earthquake in Haiti, for instance, had a magnitude of 7.0. Everyone understands that this is bigger than a magnitude 6.7, like Northridge, but few understand that the difference means that the Haiti event released three times the seismic energy of the Northridge earthquake.

And while building codes and construction standards play a big role in determining relative damage and casualties, this is often overplayed. After the 2001 Nisqually earthquake in Washington (Mw=6.8), there were commentaries in the news media suggesting that the lack of serious damage and casualties in Washington reflected poorly on standards in LA, where the Northridge event killed 67 people and caused extensive damage. Of course the primary reason for the difference is that the Nisqually earthquake occurred at a depth of 52 kilometers, versus 19 km in Northridge.

The author of the above post suggests a change in terminology, that when geologists talk to the media about earthquakes they refer to the seismic energy released by an earthquake (in tons of TNT, rather than joules of course). This would be roughly equivalent to reporting the seismic moment (Mo) rather than the moment magnitude which, is just a way of correlating the seismic moment with the Richter Magnitude.

Of course the 2004 Sumatra earthquake (Mw=9.1) released 1400 times more energy than Haiti, yet the death toll in Haiti has exceeded 100,000 and may approach the quarter million that were lost in 2004 (though most of those deaths were attributable not to the earthquake but to the tsunamis that crossed the Indian ocean as a result). As with the Northridge/Olympia example above, the Haiti earthquake had a focus just 13 km beneath the most densely populated region of Haiti, while the Indian ocean quake was 30 km deep and hundreds of kilometers from the nearest populated area (of course it also displaced the floor of the ocean by approximately 30 meters, generating the tsunami).

My suggestion would be to scale the seismic moment to the distance between the earthquake's focus and the nearest populated area (where energy decreases with distance squared). This does not take into account that a significant portion of energy is released as heat and deformation of materials. It also ignores the complexities of subsurface geology and the unique character of individual focal mechanisms. But I think it would go a long way toward expressing to the general public the relative seriousness of different earthquakes.

Here are a couple of back-of-the-envelope examples. In Haiti, Olympia and Northridge I've scaled only for depth, as the foci were more-or-less directly beneath the affected populations. I begin with the assumption that a magnitude 4 event is the energy equivalent of 1 kiloton of TNT:

Update: Hypocentre contacted me below and pointed out my math errors, which have been corrected in the table.

Though the actual mechanics, geology and secondary effects (such as tsunami and landslides) are different in each situation, these adjusted energies seem to be a reasonable approximation of the casualties and damage for these six earthquakes.

I think this is a relatively easy adjustment to make in reporting events, and conveys much more information to the public than the current method. I'm interested in people's comments...

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***Note that the IRS has been instructed to allow tax-deductible donations to Haitian relief made in the current year to be deducted on your 2009 taxes. Give generously.

Red Cross
Oxfam America
Doctors Without Borders
www.hopeforhaitinow.org

Who can believe a scientist?

Dave Petley already wrote about Richard Alley's talk on climate feedbacks; aside from reiterating his call for everyone to go to the archive and watch the webcast, I have nothing to add except that I wish I could tell a story half as well as Richard...

I also attended Leo Hinzman's lecture on arctic hydrology and permafrost response to climate change, and an education session this morning on climate literacy and communication with the public. I think it was Steve Newton from the National Center for Science Education, giving a talk entitled Creationism and Climate Change, that threw me over the edge.

OK, I admit it -- I saw 2012. My story (and I'm sticking to it) is that I had several students in my intro astronomy class (and one or two in my geology classes) ask me the "plausibility" question. I told them that there were several factual elements in the movie: people in the United States do, in fact, speak a form of the english language; there are places in the United States called California and Yellowstone National Park (though they seem to be a lot closer together in the movie than in real life -- I would take all of my classes to Yellowstone if the trip out-and-back were as short as it is for John Cusack and his kids); and geologists are, in fact, heroic figures everyone should look up to.

But, I assure them, everything else you see in this movie is fantasy: the idea that the Mayans predicted the end of the world, that neutrinos could evolve into anything other than different types of neutrinos, that a tsunami generated even by a magnitude 9 earthquake could swamp a ship in the middle of the ocean, or that a tsunami generated by any earthquake could swamp the Himalayan plateau. But now all of that seems incredibly plausible to me compared with the biggest fantasy the movie throws at us: that a single scientist (or a few scientists) could come to the world's leaders with news of an impending environmental disaster and the leaders respond with focus and determination. OK, with focus and determination to save themselves and their rich benefactors, but there was not one call for additional study, or an ad hominem attack on the scientists, or lobbying campaign suggesting that the end of the world was "just a theory," etc...

Roland Emmerich has digitally destroyed cities across America (OK, mostly LA, New York and DC) and the world in Independence Day, The Day After Tomorrow, and 2012. But his greatest CGI sleight of hand is creating worlds where people listen to warnings from scientists...

Pseudo-plutonic rocks of Moscone South

Granodiorite: low mafics, plagioclase dominant.











Granite: quartz and orthoclase.











Gabbro (?): mafics dominate, apparently as aesthetic choice to include orthoclase.

AGU, monday night

I attended a session on early solar system dynamics this morning. It included a talk on orbital eccentricity and distance (and how they change as the sun loses mass) in which the author concluded that the Oort cloud cannot exist, but I need to look more closely at his numbers before I comment on any of it. Suffice it to say I'm a fan of the Oort cloud with its long period comets and highly inclined orbits...



One interesting talk was Age of the Solar System Revisited (Wadhwa and Bouvier). Someone once suggested that the age of earth is a function of time. In his Universe Song, Eric Idle quotes some numbers about size, velocity, mass, and sheer number of stars that reflected the knowledge at that time. In a recent interview his co-author, acknowledging that some of the numbers were understood to be different now, offered that "the facts have changed." "No", Idle replied, "the facts haven't changed -- our understanding of the facts has changed."

Our understanding of the age of the earth is based on the age of meteorites. Radiometric dating of meteorites depends on the same key assumptions as dating of other types of rocks, the key assumption being that we're dealing with a system that has been closed since the event we're trying to date.

The formation of planets from smaller planetessimals implies a fair amount of alteration, and at least part of our understanding of earth's composition is based on the existence of meteorites derived from asteroids that went partially down the planet-forming path -- that is, they became large enough and hot enough to differentiate into a core and mantle. So dating any old meteorite fragment won't do.

A significant fraction, perhaps 90%, of interplanetary debris contain chondrules (from the Greek chondros, meaning grain). these tiny particles consist of mostly devitrified silica-glass droplets, and the meteoritic bodies that contain them (called chondrites) have the appearance of sedimentary rocks. The cooling history of the grains supports the idea that chondrites are formed by the agglomeration of smaller solid particles, as the chondrules cannot have been cooled from a melt to form a rounded droplet within the meteoroid. Chondrules, in fact, appear to be among the oldest solid particles within the solar system. I say among the oldest because chondritic meteorites also contain Calcium-Aluminum-rich inclusions (CAIs, which include, but are not limited to, anorthite and pyroxene) that formed at higher temperatures, and pre-date the formation of the chondrules by perhaps 2 million years.

In this talk the authors look at the results from sampling CAIs from several carbonaceous chondrites (these are chondrites that not only contain small amounts of volatiles, but their refractory composition is close to 1:1 with that of the sun). these samples give dates varying from 4.5676 +- 0.001 to 4.5687 +- 0.002 billion years based on Pb-Pb isochrons. the same meteorites yielded more consistent model ages using Al-Mg and Hf-W systematics. The group claims that there is a yet unidentified problem with Pb-Pb system in these meteorites, suggesting that perhaps the problem is that the initial 238U:235U ratios are not as consistent from sample to sample as has been assumed.