Thursday, December 24, 2009

Some Good Holiday Listening and Reading

Here's a list of holiday whiling-away's for you:

Literary and Musical Stuff:

1) The Definitive Dickens- Tom Ashbrook discusses a new biography of Charles Dickens with biographer Michael Slater

2) Alexander McCall Smith- Author of No. 1 Ladies Detective Agency talks about his work and life in Africa and Scotland.

3) Thelonius Monk - Terry Gross of Fresh Air talks with Robert D. G. Kelley  about the Jazz genius.

Sciency Stuff:

1) Is Evolution Predictable? Simon Conway Morris writes about it in the context of evolutionary convergence.

2) A Christmas Carol - Economist Steve Landsburg explains why Scrooge has been getting a bum rap from society.

3) Gene Patenting - Should your genes be patented and how the process impacts research and you.

4) U.S. Health Care - David Brooks looks at it as an ultimately values question.

Silly Stuff:

1) Nazis and GIS - Adolf Hitler is not pleased with the latest version of ArcGIS software.

I won't be posting now until early January.

Wishing everyone Happy Holidays!

Tuesday, December 22, 2009

K-12 Earth Science Education Status Report For The U.S.

Something for geology / earth science educators. The American Geological Institute has released a status report for the year 2007 titled "The Pulse of Earth Science Education" which follows earth science education trends in 50 states.

Go here to access the information.

The AGI provides information on:
  • teacher certification requirements
  • relevant middle and high school courses
  • K-12 enrollment levels
  • Earth science within state science standards
  • state assessment of students
  • textbooks adopted and relevance to Earth science
  • contact information for state education agencies
via Geology.com

Monday, December 21, 2009

Geothermal Energy And Earthquakes

Theunis Bates at Sphere has a good write up about the link between geothermal energy projects and earthquakes.

These projects are controversial. The company that started a geothermal project in Basel, Switzerland is facing lawsuits for allegedly triggering earthquakes. Another project in California was recently canceled due to similar earthquake fears.

From the article:

Paul Younger, a professor of energy and environment at Britain's Newcastle University, says that it's not unusual for much smaller tremors to be felt on the surface when pressurized water is forced into rock deep underground. But, he adds, the process is normally only carried out in seismically stable areas, as the shakes caused by hydro-fracturing can interact with existing deep faults and cause larger trembles.

And Basel is anything but stable. The city has a long history of quakes and was all but wiped out in 1356 by an estimated magnitude 6.5 earthquake – the largest ever known to have occurred in Western Europe. "What they were doing was actually fairly conventional," Younger says. "It's where they were doing it that was unconventional. If you go drilling and stimulating near a known active fault, you're asking for trouble."

That may raise a question. Why not just drill in portions of the crust that are known to be structurally very stable and which have no active faults?

....geothermal projects will almost always be located in geologically active areas with lots of faults and which are earthquake prone because the required heat will be found at shallower depths making such locations economically more attractive than drilling deeper in colder more stable parts of the crust.

As our understanding of faults in geologically active regions increase it may be possible in the future to more carefully select sites based on how "stressed out" individual faults are....but there will always be a general overlap between geothermal sites and earthquake prone areas.

Here is the situation for India. Earthquake potential (increases in darker shaded areas) compared with geothermal potential. There is large overlap as expected.



According to a report by D. Chandrasekharam of the Indian Institute of Technology Mumbai, the geothermal provinces of India have a potential to produce around 10,600 MW of power. I haven't seen other government figures for this.  The Ministry of New and Renewable Energy website does not have the numbers for geothermal. 

In any case, if this industry is to have a future, geologists and engineers will have to grapple with the connection between attractive geothermal energy sites and potential earthquake hazards and also importantly develop strong transparent public outreach mechanisms to disseminate information for review and debate.

Tip: Geology.com

Saturday, December 19, 2009

Get The Beer Out: The Geologists Are Coming

Wired Science has a fun article by Betsy Mason on why geologists like beer. The fluid has been flowing freely at the recent AGU meeting in San Francisco and bartenders are swearing that geology conferences see more of that stuff being consumed than at any other science meeting.

Why do geologists love beer so much?

When it’s hot, and you’ve been hiking all day carrying 50 pounds of rocks, do you want a Merlot? - Jim Metcalf of Syracuse University

It goes down a lot easier than water because a lot of the places we go, we can’t drink the water - Jonathan Gourley of Trinity College.

Science doesn’t work when people keep secrets and don’t share their data, And what could be better to help with the free flow of information? - Daniel Jaffe of the University of Washington.

More theories here:



In India you get a decent collection of lagers but not much selection in ales. Hopefully that might be changing soon. I attended a wine festival in Pune last year and there were stalls by a couple of breweries showing off their new ales which will be in shops soon.

Good stuff.

I drink mostly  Okocim Palone  a Polish  malt lager which is now being brewed in India. In my opinion it is the best of the Indian lagers. Richer, toastier and more flavorful than the rest.



....geologists in India gulp down a lot too.

Thursday, December 17, 2009

Unfolding The Earth With Some Novel Map Projections

New Scientist has run a piece describing the work of Dutch computer scientist Jack van Wijk's work on novel map projections.

From the press release:

"Myriahedral projection" was developed by Jack van Wijk, a computer scientist at the Eindhoven University of Technology in the Netherlands.

"The basic idea is surprisingly simple," says van Wijk. His algorithms divide the globe's surface into small polygons that are unfolded into a flat map, just as a cube can be unfolded into six squares.

Cartographers have tried this trick before; van Wijk's innovation is to up the number of polygons from just a few to thousands. He has coined the word "myriahedral" to describe it, a combination of "myriad" with "polyhedron", the name for polygonal 3D shapes.

Check this out: You can try to fit the earth's surface on unfolded nets of different shapes.




The new algorithms though go a step further. The nets have many more sides and are shaped more intelligently in ways that arrange continents and oceans in different configurations but with minimum distortion to their shapes where they are cut and unfolded.

For example here the oceans are one continuous expanse surrounded by coastlines




You can see the rest of the maps at this picture gallery

Jack van Wijk won the Cartographic Journal's Henry Johns award for the best map-making research paper of the year.

Monday, December 14, 2009

Weather Ain't The Same As Climate Mr. Aiyar

It's amazing how much confusion there still is between weather and climate.

Mr. S A Aiyar writes a well read and well respected economics column in the Times of India. I like his columns. He has a gift for explaining complex topics in a succinct and simple manner. He gets it right a lot. Rarely though is he so completely wrong.

Like here where he tries to explain why climate projections can't be trusted:

If new technologies cannot reduce emissions by 80% save at a huge cost that causes economic distress, governments will abandon emission targets. They will not deliberately create deep recessions just to curb emissions.

Will this lead to climate disaster? Maybe and maybe not. Scientific knowledge of the weather is very limited, and Intergovernmental Panel on Climate Change (IPCC) projections are just intelligent guesstimates. IPCC scientists may be the best in the world, yet they cannot predict the weather more than five days ahead.

Can they predict the next drought in India? No. The next El Nino? No. The number of hurricanes in the Caribbean next year? No. So, can they accurately predict the weather 100 years hence? Surely not. When we know very little about a problem, we tend to worry endlessly about worst-case scenarios. That does not make the worst case certain, or even probable.

He's right when he says that climate scientists cannot predict the weather 100 years hence.

But they are not trying to. That's not what climate scientists do.

Weather is the day to day or short term atmospheric conditions. Climate and climate change is about long term changes in average weather. If you want to know what the weather will be on a Sunday 100 years from now you will still have to rely on a meteorologist to tell you 3 days before that Sunday.

Climate scientists on the other hand will tell us that if you take a ten or twenty year interval 100 years from now, the average temperature of that interval will be higher than today.
 
That much is a near certainty and it follows from the basic greenhouse effect. If we keep emitting greenhouse gases the earth will warm up. What is uncertain is by how much and what exact regional effects will it have. That's where the climate models and IPCC projections come in. And they show a range of possibilities depending on assumptions made of starting conditions, emission trajectories for different economies and not yet well understood positive and negative feedback's in the climate system.

For drafting sensible policies to reduce emissions we don't need to know whether a series of powerful hurricanes will hit New Orleans in year 2102 or whether they will hit it in 2105 or the exact year in which India might face a crippling drought in the future.

Its enough to know that 100 years from now these events will be more common (update: or more intense). And our current and improving understanding of climate change does provide enough confidence on that issue, more than Mr. Aiyar wants to give it credit for.

Its a shame that a person as erudite as Mr Aiyar has misrepresented climate science and misinformed the public in so blatant a manner.

Friday, December 11, 2009

Can India Cut Emission Intensity Without Carbon Sequestration?

Yes, is the answer at least according to the Indian government.

A reader left a comment on my previous post on the distribution of potential basalt and ophiolite carbon reservoirs asking:

In your original post you suggested this was probably a non-starter for India, given our unwillingness to implement cuts in emissions. Do you think recent moves by China (and now more modest ones by India) to cut emission intensity will change the equation at all?

The original post was the one on Deccan Basalts as a potential reservoir for carbon sequestration projects.

I don't know about the Chinese plan but the 5 point plan put forward by Mr. Jairam Ramesh the Minister of Environment and Forest, India, to cut carbon emission intensity does not include carbon sequestration as a strategy.

Instead the government is aiming to reduce emission intensity by 20-%-25% by 2020 using:

1) Mandatory fuel efficiency standards for vehicles by December 2011
2) Mandatory green building code
3) Amendments to energy conservation Act
4) Progress report on forest cover
5) 50% of new capacities in power plants to be based on clean coal technologies

If you think these are big concessions by the Indian government you would be wrong. There is nothing really radically new about the way India plans to achieve its voluntary target of reducing emission intensity. That process was already underway much before Mr. Jairam Ramesh's announcement.

Emission Intensity is a measure of the energy efficiency of your economy - emissions per unit GDP - and between 1990 and 2005 India reduced its emission intensity i.e. improved its energy efficiency by about 17%.

Automobile makers have been steadily improving vehicle efficiency for years. Other industries too in an effort to be competitive have been streamlining their processes and improving efficiency. The Indian government years ago has set targets for expanded forest cover. Even India's notoriously  wasteful coal power plants have been improving their efficiency over the last few years and a large fraction - as high as 60% to 70% - of  new coal plants from both the public and private sector will be built using cleaner technology, the so called supercritical coal plants which use advanced coal combustion technology. This trend is being driven not by government fiat but by the rising price of coal due to increased demand and the need to import larger quantities of the fuel.

All this implies that this new target the government has announced won't require politically difficult decisions. Instead, the government is relying along with a few nudges and pushes on the naturally growing efficiency of industry to achieve a large fraction of the target of reducing emission intensity.

On the other hand geoengineering strategies like carbon sequestration which avoid emissions altogether face several hurdles. For at least the immediate target of reducing intensity by 2020 the science and technology may not be ready. Sequestration is also expensive. This means coal plants will have to bear much higher costs than they would voluntarily agree to. And that means government regulations and tough political decisions. And there are potential land acquisition issues that may come up if the sites chosen for sequestration projects underlie agricultural or forest land.

So emission intensity riding on the back of increasing efficiency of the Indian economy is likely going to be the government mantra for some time to come.

Unfortunately increased warming is a result of the total amount of greenhouse gases accumulating in the atmosphere. And those despite a reduction in emission intensity will keep increasing, although at a slower rate.

Tuesday, December 8, 2009

Nice Map Of Basalt and Ophiolite Potential Carbon Reservoirs

Here is a great looking world map which shows the distribution of continental  basalts (a) and ophiolite complexes (b). Ophiolites are slices of the earth' s oceanic crust and upper mantle that have been exposed on land by tectonic forces. They are found along ancient and modern convergent plate settings i.e. regions where two plates are converging and colliding with each other.

Can these mafic igneous rocks act as reservoirs for storing carbon dioxide?




Source: Permanent storage of carbon dioxide in geological reservoirs by mineral carbonation

The article is open access. I posted about this article before but more from the perspective of the Deccan Basalts as a potential CO2 reservoir and how that might conflict with other more immediate uses of that rock body.

I thought I'd pass along the link to this map too.

Nature Geoscience Issue On Carbon Dioxide Sequestration

The December issue of Nature Geosciences has a series of articles on carbon sequestration. The editorial is behind a pay wall but the Correspondences and Commentaries are open access.

There is an interesting article on the geopolitics of geoengineering in which the author Philip Boyd raises the concern that the benefits and unintended detriments of geoengineering strategies would be spatially non-uniform and might lead to conflict between nations:

....A key concern is the scale on which geoengineering strategies, both for solar radiation management and carbon removal proposals, are used. Stratospheric sulphur injection and ocean fertilization would need to be adopted on a large scale and sustained over long periods of time if they are to have any globally significant effects. But it is the very scale and longevity of these schemes that makes regionally heterogeneous side effects more likely, and the potential for discord between nations more real. The unintended dispersal of geoengineering agents will only exacerbate the problem. For instance, ocean circulation will rapidly disperse modified surface and subsurface waters, which may be depleted in both nutrients and oxygen owing to fertilization-driven increases in productivity and carbon export. Such low-quality waters could infiltrate marine exclusive economic zones....

Getting global or regional political consensus on anything is damn difficult and geoengineering too will face that test. Overall the articles lean towards implementing some sort of geoengineering for controlling atmospheric CO2 levels and climate change.

Wednesday, December 2, 2009

Why Didn't Darwin Come To India?

Mauritius is the closest he got but he did use examples from India's biodiversity to bolster his case for evolution. Vikram Doctor writes an excellent article in the Times of India on Darwin's India connection.

That connection was Edward Blyth - self taught zoologist and curator of the museum of the Royal Asiatic Society Calcutta - who maintained a long and fruitful correspondence with Darwin about the animals and plants native to India.

Darwin acknowledges this contribution as

"his large and varied stores of knowledge , I should value more than that of almost any one."

This is the second impressive intellectual conversation about evolution I have come across in India via outreach and media over the last few weeks. Earlier in November at the British Library in Pune, biologist Madhav Gadgil talked about early evolutionary thinking, Darwin's contributions and recent advances in evolutionary theory.

Doctor's article too covers a lot of ground. He gives us a sense of the work and social environment struggling scientists had to face in India. I read and posted on David Gilmour's The Ruling Caste: Imperial Lives in the Victorian Raj recently. It describes the day to day lives of British civil servants in 1800's India. Their lives were hard but Blyth faced an additional problem. He stood outside the administrative hierarchy and was on a weaker social standing than other officers of the civil services. Self taught scientists from poor backgrounds were looked down upon by the Raj officers who during the mid 1800's mostly came from Britain's upper classes. There is a lot packed in the article on the difficulties and tribulations Blyth faced during his career in India.

Doctor's article also clarifies the controversy on whether Darwin really deserved the credit for his work or whether as some say he plagiarized Alfred Russel Wallace's ideas who had coincidentally discovered natural selection around the same time. That Wallace proposed a theory of evolution through natural selection is undeniable,  but both Wallace and Blyth recognized that just presenting an idea is half the work in science. Backing it up with evidence is harder. Darwin besides proposing a theory also did the hard work of compiling the evidence for evolution through natural selection. He can rightly claim most of the credit.

As an aside and something Doctor does not get into is that Wallace too has been painted in extremes. For some, he should be placed on a higher pedestal than Darwin. Others say - unkindly - that his only real contribution was that he hastened Darwin into publishing a shorter, streamlined and more accessible version of his theory. Darwin's earlier plan to publish a tome running into several thousand pages was shelved in fear of being scooped upon receipt of Wallace's theory. Still others point to the latter part of Wallace's career when he doubted that the human brain could be a product of evolution and use that to discredit him.

That is in my opinion just...well unkind. Wallace did discover natural selection independently and contributed valuable insights into other fields like biodiversity, natural variability of populations and bio-geography. That he could not compile evidence like Darwin did or that he leaned towards mysticism later in his life does not diminish the originality and importance of his earlier work.

Having said that, convincing people that evolution had occurred required evidence. And there is no doubt that Darwin made a better case for it than anyone else in his times with a little help from friends and colleagues like Edward Blyth.

Vikram Doctor's article is a pleasure to read. And...yes he does offer an answer to why Darwin didn't come to India.  Don't miss it.

Monday, November 30, 2009

Mapping India: Land Degradation and Desertification

In the November 25 issue of Current Science, researchers from the Indian Space Research Organization release a map and some important estimates of the extent of land degradation and desertification affecting mainly dry, semi-arid and dry- sub humid areas of India.



Source: Desertification/land degradation status mapping of India

About 69% of the total land area of the country - about 228 million hectares - falls in one of these three climatic categories. The numbers from this mapping project is cause for concern. They indicate that land degradation has affected just under half the extent - 105 million hectares of these dryland regions,  roughly 32% of the land area of India.

The main processes of degradation are water erosion, wind erosion and vegetal degradation through deforestation and overgrazing. The paper gives the extents affected by various degradation processes grouped state-wise.

I wish they had included estimates of degradation by land use. For example how much of agricultural land in each state is being degraded, how much forest and so on. These have been no doubt calculated. They show up as classes on the map, but the paper does not present the results by type of land use affected.

If predictions about changing rainfall patterns over India because of climate change turn out to be accurate they will accentuate many of these degradation processes. Rainfall is predicted to fall in shorter more intense bursts over many regions of India. This would mean more powerful surface runoff and greater soil erosion.

Regions of country which are hot and arid like Gujarat and Rajasthan are likely to get hotter and drier. That would mean more stress on vegetation and great wind erosion.

I come back to the National Action Plan For Climate Change (15 MB) There are 8 missions or strategies to deal with climate change. None of these directly includes the problem of land degradation and desertification in dryland regions. However the National Water Mission, National Mission for a Green India and the National Mission for Sustainable Agriculture seem to have the right overlapping goals that could be focused to address this problem.

I mentioned earlier about the estimates of land degradation according to land use. These numbers matter a lot. Farmers occupying dryland regions are usually poor farmers cultivating marginal lands. If you look at the above map, you will see large regions classified as Agriculture Unirrigated being affected by various processes of land degradation. These are farmlands that are out of the reach of irrigation canals and other State largesse.  Millions of farmers cultivate small land holdings, depending only on monsoons and groundwater. Warming and changing rainfall patterns will have a larger impact on these marginal farmers. Their livelihoods and the food security for large number of people in these drylands is at risk from continuing damage to the land.

The National Action Plan For Climate Change needs to single them out for special help.

Thursday, November 26, 2009

Charles Darwin Has Been Sighted In Pune

Its been 150 years - November 24th 1859 - that Darwin's book On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life was published.

The British Library on Fergusson College Road, Pune, has a poster exhibit on the theory of evolution. There are 14 poster boards encompassing the gamut of thinking on evolution beginning with Charles Darwin's voyage to the Galapagos to his subsequent theories of common descent and natural selection to current understanding on topics like speciation, group selection, the evolution of attributes like musical ability  - which provides food for thought on whether every feature can be explained as an adaptation or whether some traits originate as spandrels or byproducts of the evolution of some other general feature - to recent thinking on the genome and the importance of mechanisms like epigenetics and gene regulation.



Source: British Council

Earlier on November 12th, biologist Madhav Gadgil gave quite a good talk on the relative roles of cooperation and competition in evolution. He spent quite a bit of time clarifying some common misconceptions about evolution, most notably the (mis)concept of an ideal type. That there is an ideal type or a narrow collection of attributes defining species and populations can be traced to essentialist thinking prevalent since...well since recorded philosophy of thought. One consequence of this thinking is that any individual of that group who exhibits variation outside that "ideal" or narrow range is considered an aberration of nature, a degenerate. Madhav Gadgil very eloquently dispelled that notion and stressed that variation is the norm of life, the fuel which drives evolution.

The sizable crowd which had gathered for the talk asked some thought provoking and challenging questions. There were more technical questions -  does the theory of the selfish gene underlie co-operation?...I don't quite remember Dr. Gadgil's answer but here is my take on this.  In his book The Selfish Gene Richard Dawkins argues that you can think of natural selection as acting on genes and not the individual. All genes are selfish since their "goal" is to replicate themselves at the expense of their alternative version. Can this explain co-operation?  Yes ...in a very general sense if one is thinking of evolution in terms of gene selectionism then co-operation like any other attribute spreads through the spread of selfish genes.

There were also discussions on social Darwinism and how a clearer understanding of evolution - by removing misconceptions like racial purity and group superiority - can help us become a better society...never forget....fitness is local and ever changing and variation is everything....

A few canards were repeated during the talk and discussion, most notably how Hitler was directly influenced by Darwin. He wasn't.  He had not read Darwin and had no understanding of evolution and neither did his coterie. Maybe there were a few people throwing around phrases like survival of the fittest but really a heady mix of a radical Christian sense of racial superiority and extreme nationalism more convincingly explain his conversion to arch fascist. Check out this article and this one for a humorous but informative take on the subject.

If you are in town go stop by the British Library. The exhibition runs until November 29th.

Tuesday, November 24, 2009

California Droughts And Carbonate Cycles

When I was a graduate student in the mid 1990's one of the hot research topics in carbonate sedimentology was the study of shallow marine carbonate depositional cycles. Sediments in shallow marine and even deeper environments  are deposited in packages or cycles during periodic sea-level rise and fall. There is a rhythmic beat to this, regulated by the waxing and waning of polar ice sheets or by periodic tectonic subsidence or by an internal clock beating to changing currents and sediment distribution patterns. The periodicity of these cycles is on the scale of tens of thousands of years.

Which of these mechanisms is dominant? That was the big question and the big fight.

GSA meetings used to be fun listening to rival research groups intellectually slug it out. Over the years the waning and waxing of ice sheets (allocyclicity) has been recognized as a common mechanism of generating sediment cyclicity but to give other processes their due, tectonic subsidence and autocyclicity i.e internal forcing due to self regulated sediment accumulation and distribution patterns are also recognized from specific environments.

We worry about a lot of other problems these days, global warming and its effects of rainfall being one. Scientists involved earlier in their career in the study of marine carbonate cycles have started paying attention to geological beats taking place on a much higher frequency.

Isabel Montanez who has published a lot on marine carbonate cycles has a paper with graduate student and colleagues on the rhythmic precipitation of carbonate minerals within cave stalagmites from the Sierra Nevada mountains of California.

Late Pleistocene California droughts during deglaciation and Arctic warming - Earth and Planetary Science Letters

And here is the Science Daily press release.

Cave stalagmites form by minerals precipitating from water dripping from the roofs of caves. Growth speeds up during the rainy season and slows or stops during the dry periods. Growth bands can thus reflect yearly growth much like tree rings. This allows scientists to resolve changes taking place over tens of years. One fairly long stalagmite can record growth over hundreds to few thousand years. In this study the scientists have a record of stalagmite growth - radiometrically calibrated - over a time interval from about 16.5 thousand to about 8.8 thousand years ago covering the end of the last ice age.

During this time interval the climate record from Greenland indicates alternating warm and cold periods lasting a few hundred to a few thousand years.  In California the chemical composition of the stalagmite measured over the same time period indicates that during the Greenland warm periods California became drier while Greenland cold periods corresponded with a wetter California.

How do you find this out? Of major interest are the variations in the oxygen isotopes and to a lesser extent the carbon isotope composition of the calcite in the stalagmite.

A graphic makes the geochemical life of oxygen isotopes easier to conceptualize.



Source: SAHRA

The ratio of two oxygen isotopes  18O and 16O are measured. The notation d18O  refers to the ratio of  18O to 16O. The more negative value of d18O   means enrichment in 16O. 16O being the lighter isotope is preferentially enriched in the vapor phase. So if it rains only a little then the precipitation is going to be enriched in 18O. If it rains a lot i.e. if most of the moisture in the air condenses then eventually the rains will become more and more enriched in 16O.

This is called the rain out or amount effect.

This oxygen in the rain eventually ends up in the mineral calcite precipitating on the floor of the cave. In the graphic above substitute initial precipitation and later precipitation taking place in different places to less rain and more rain taking place at the same location. 

Drier conditions will result in the mineral calcite that makes up the stalagmite growing from relatively 18O enriched water (elevated d18O ) and wetter periods will result in growth from relatively 16O enriched waters (depleted d18O).   These changing values are encoded in the calcite growth bands of the stalagmite. The scientists have found with disturbing implications for future California climate that in the past, a decline of ice sheets and warmer climate resulted in a drier California. History is giving us a warning about the expected rainfall patterns over California.

A quick note on carbon isotopes. Here two isotopes 13C and 12C are measured. Organic carbon is enriched in the lighter isotope because plants preferentially take up the lighter isotope during photosynthesis. During wet periods when the ground above the cave roof supports a lot of vegetation, the water seeping through the vegetation will incorporate a lot of the lighter isotope. During dry periods the water seeping through the cave roof will have relatively less of the lighter isotope. So dry periods will have an elevated d13C value (ratio of 13C and 12C).

So rhythmic deposition or precipitation of carbonate cycles over a wide range of time scales gives us different types of information about earth processes.

Cycles deposited over tens of thousands of years in marine basins tell us about either external controls on sea-level rise and fall like the periodic changes in the earth axial tilt or orbital parameters. Or they tell us about local tectonics changes or other internal regulating mechanisms.

On a decadal scale, precipitation cycles of calcite in stalagmites, may tell us about changing rainfall patterns and warn us about future droughts and water shortages.

Occasionally they may even give us insights into social and cultural upheavals such as the rise and fall of Chinese dynasties. Check out this finding. Its uses the same isotope principles from cave deposits to unravel Chinese climate history over the last thousand years or so and its impact on the Tang, Yuan and Ming dynasties in China. 

None of these press releases though have actually explained the isotope effect.

Which kind of irritated me and prompted this post.

Sunday, November 22, 2009

Israel -Jordan Border: Rodents Too Behave Differently

This from a Science Daily press release on the differences in ecosystems and animal behavior across the Israeli Jordanian border :

....the differences between Israel and Jordan are primarily in the higher level of agriculture and the higher number of agricultural farms in Israel as opposed to Jordan's agriculture that is primarily based on nomadic shepherding and traditional farming. The agricultural fields on the Israeli side of the border not only create a gulf between habitats and thereby cause an increase in the number of species in the region, but they also hail one of the most problematic of intruders in the world: the red fox. On the Jordanian side, the red fox is far less common, so that Jordanian gerbils can allow themselves to be more carefree. The higher reproduction rate of ant lions on Israel's side is also related to the presence of another animal: the Dorcas gazelle. This gazelle serves as an "environmental engineer" of a sort, as it breaks the earth's dry surface and enables ant lions to dig their funnels. The Dorcas gazelle is a protected animal in Israel, while hunting it in Jordan is permitted and compromises the presence of the Jordanian ant lions' soil engineers.

Important lessons for conservation here.

Wednesday, November 18, 2009

Speeding Up Mineral Reactions To Fight Global Warming

The more familiar method of carbon dioxide sequestration involves capturing and pumping the gas into underground reservoirs where geological traps that have sealed natural gas for millions of years will serve to lock captured CO2 for eons as well.

Nature has published a paper by Jürg M. Matter and Peter B. Kelemen that proposes another method of CO2 sequestration, locking CO2 as carbonate minerals by reaction with a host rock.

Anthropogenic greenhouse-gas emissions continue to increase rapidly despite efforts aimed at curbing the release of such gases. One potentially long-term solution for offsetting these emissions is the capture and storage of carbon dioxide. In principle, fluid or gaseous carbon dioxide can be injected into the Earth's crust and locked up as carbonate minerals through chemical reactions with calcium and magnesium ions supplied by silicate minerals. This process can lead to near-permanent and secure sequestration, but its feasibility depends on the ease and vigour of the reactions. Laboratory studies as well as natural analogues indicate that the rate of carbonate mineral formation is much higher in host rocks that are rich in magnesium- and calcium-bearing minerals. Such rocks include, for example, basalts and magnesium-rich mantle rocks that have been emplaced on the continents. Carbonate mineral precipitation could quickly clog up existing voids, presenting a challenge to this approach. However, field and laboratory observations suggest that the stress induced by rapid precipitation may lead to fracturing and subsequent increase in pore space. Future work should rigorously test the feasibility of this approach by addressing reaction kinetics, the evolution of permeability and field-scale injection methods.

The advantage here is that the gas is converted into a solid phase and so exists in a more stable form. The principle may be sound but I'm going to think out aloud on bridging the very long distance between scientific possibility and its practical realization in the field for a country like India.

First come the political and economic issues with a scheme of this nature. Those hurdles are immense. India's stated position is of no mandatory limits on emissions, so there is no political urgency in examining CO2 sequestration projects like this one. And this method is going to be expensive as well. Transporting CO2 from emission points to suitable storage sites and then drilling and pumping gas in hard rock ain't going to come cheap. It might work if the price of emitting CO2 is very high. But under the current scenario in India with no limits or penalties on emissions there will be no economic incentives for polluters to even explore a scheme like this.

Besides, there are other urgent practical matters that need to be carefully thought out before rock masses can be given out for CO2 storage.

There is no problem in India finding a suitable host rock. In Maharashtra and adjoining states of Madhya Pradesh, Andhra Pradesh there is half a million square km of Deccan Basalts, a rock rich in magnesium and calcium that will provide plenty of reaction surface and storage volume. This potential reservoir is up to 2 km thick in the central portions and along the western ghats. Other areas of the country too have mafic igneous rocks of the right composition that may extend to even deeper crustal levels.

However... where do you drill and store and to what depth before the project becomes too expensive?...

A crustal thickness of up to 1 km underlying cultivated areas must be kept untouched only for groundwater storage. That may seem excessive since groundwater is extracted mostly from the upper few tens to a hundred feet or so. But the Deccan Basalts and other mafic crystalline rocks have deeper aquifers too. Already these are being exploited by groundwater bore-wells that are reaching a few hundred meters in many parts of the country as demand for the groundwater increases.

Water in these crystalline rocks is stored and moves along fractures and cracks. Fracture systems in these rock masses penetrate to great depths and must be kept open if the rock is to act as an effective aquifer.  The danger is that gas pumped to depths even greater than 1 km may seep up through these deep penetrating fractures depositing carbonate minerals and plugging up the shallow permeability pathways for groundwater.

You could in principle go to very great depths say much more than 2 km, but at some point drilling through the hard crystalline rock will make the project uneconomic.

So then.... if the choice is between pumping CO2 into the crust to economically viable depths to keeping aquifers healthy, then the health of the aquifers must win out. Timely groundwater access improves crop yield and farmer income. The relation is direct and the benefits immediate. Risking reducing the  porosity and permeability of these rocks with carbonate minerals to attain a more nebulous benefit (for people who depend on groundwater) of lowered atmospheric CO2 content will be a suicidal course to take and I unfortunately mean that literally.  Groundwater irrigates a major share of cultivated areas and access to it offers the best chance of alleviating grinding farmer poverty in face of uncertain rains and lower crop yields due to increased temperatures.

So, no playing around with rock masses under cultivated areas...that might leave sections of the crust underlying wastelands, forests and urban areas as potential sites. Of these wastelands appear as the most promising sites in terms of the least political and civic resistance to such a project. This provided field experiments demonstrate the feasibility of this project and the political and economic conditions allow its implementation.

India's National Action Plan for Climate Change (15 MB) has very little to say about carbon sequestration. None of the eight missions or strategies meant to deal with climate change include carbon capture and sequestration.

It is under the political radar and it is expensive and India can best mitigate the effects of global warming by keeping the shallow crust fractured and permeable so as to act as an effective aquifer for groundwater.

My feeling is for India at least in the near term this method of preventing atmospheric CO2 buildup is a non-starter.

Thursday, November 12, 2009

Meteorite Impact Ended Banded Iron Formation Deposition

From the November issue of Geology:

Extraterrestrial demise of banded iron formations 1.85 billion years ago; John F. Slack and William F. Cannon

In the Lake Superior region of North America, deposition of most banded iron formations (BIFs) ended abruptly 1.85 Ga ago, coincident with the oceanic impact of the giant Sudbury extraterrestrial bolide. We propose a new model in which this impact produced global mixing of shallow oxic and deep anoxic waters of the Paleoproterozoic ocean, creating a suboxic redox state for deep seawater. This suboxic state, characterized by only small concentrations of dissolved O2 (~1 μM), prevented transport of hydrothermally derived Fe(II) from the deep ocean to continental-margin settings, ending an ~1.1 billion-year-long period of episodic BIF mineralization. The model is supported by the nature of Precambrian deep-water exhalative chemical sediments, which changed from predominantly sulfide facies prior to ca. 1.85 Ga to mainly oxide facies thereafter.

I don't have access to the full paper but if this holds up here is another example of how extraterrestrial matter has shaped the geological and biological evolution of earth.  A chance meteorite impact ends a prolonged process of iron oxide deposition and enables greater amounts of oxygen to accumulate in the oceans and eventually the atmosphere. That was a precursor for the evolution of more complex cell types like the eukaryotes.

Coincidentally in the October 29 issue of  Nature is another paper which hypothesizes that the earth was dry very early in its history and much of the earth's water and hence the ultimate source of the oceans has been derived from ice rich asteroid bombardment about 100 million years after the formation of the solar system. Science Daily has the summary.

Wednesday, November 11, 2009

Arctic: Carbon Sink Or Source?

The USGS has quite an informative press release via Geology.com and a graphic depicting how warming will affect the physical structure of the soil and permafrost in the Arctic region resulting in the release of carbon dioxide and methane.



Image: Zina Deretsky, National Science Foundation

There is still some uncertainty whether warming will result in the Arctic being a net source of greenhouse gases in the short term. Example warming could extend the growing season and this extra plant growth and the migration of the tree line northwards could end up sequestering more carbon dioxide than before. However sustained thawing and release of trapped gases over several decades may eventually overwhelm this balance and result in the Arctic becoming a net source of greenhouse gases.

Interesting statistic: Currently the Arctic releases about 50 million tons of methane per year. That might increase to several times more in the years to come. Methane is a more potent greenhouse gas than carbon dioxide, about 23 times more effective in trapping heat than CO2 on a 100 year time scale, so Arctic warming effects are a real cause for worry.

Friday, November 6, 2009

You'll Understand Homeopathy If You Understand Einstein

....Homeopathy - can it get more stupid than this...?

Warning: Advanced degree in physics and chemistry required to follow this discussion:



Now you know why those white pills pack so much punch! They are literally powder kegs of energy.

Thursday, November 5, 2009

Isolating Nuclear Waste At Yucca Mountain

BLDGBLOG has an interview with Abraham Van Luik, a geoscientist with the U.S. Department of Energy.

Its a long interview about isolating nuclear waste. Yucca mountain and its geology feature prominently.

Definitely worth reading.

Teaching Human Evolution In Pakistan Can Be Dangerous

Kenneth Chang of New York Times has written an interesting summary on the teaching and acceptance of evolution across Muslim countries and among Muslim immigrants in many western nations.

Atomic physicist Pervez. A Hoodbhoy went through a dramatic moment while lecturing at a university in Pakistan:

Pervez A. Hoodbhoy, a prominent atomic physicist at Quaid-e-Azam University in Pakistan, said that when he gave lectures covering the sweep of cosmological history from the Big Bang to the evolution of life on Earth, the audience listened without objection to most of it. “Everything is O.K. until the apes stand up,” Dr. Hoodbhoy said.

Mentioning human evolution led to near riots, and he had to be escorted out. “That’s the one thing that will never be possible to bridge,” he said. “Your lineage is what determines your worth.”

Its scary that this took place not at some isolated madrassa but at a national university. Overall acceptance of evolution - especially human evolution - is low in Muslim countries. The technological advancement engulfing these countries is not necessarily paralleled by a more scientific mindset among citizenry. Religious beliefs are playing a large role in driving a wedge between the two. Turkey is a great example. Just 2-3 decades ago creationism was not a factor affecting science education in Turkey. Today, the influence of Islamic parties is greater in society, evolution teaching is diluted at the school level and creationist textbooks are influencing biology syllabus.

The article does not mention Muslims in India but I doubt if attitudes towards evolution are significantly different among Indian Muslims.

And I wonder what the break up would be according to educational level and how it compared to Hindus.

Monday, November 2, 2009

End Cretaceous: How Many Impacts? How Many Iridium Anomalies?

Looking over the recent GSA geoblogosphere page I was alerted to a presentation by Shankar Chatterjee and colleagues on the Shiva crater, a hypothetical impact crater that Chatterjee claims is of end Cretaceous age and is likely responsible along with the Deccan volcanism for the mass extinction. He suggests that the Chicxulub impact event in Mexico also timed to the end Cretaceous did not alone cause the mass extinction.

Here is the abstract. The talk apparently got a skeptical reception. Chatterjee envisions the following scenario. The meteor hit the Indian continental plate and maybe initiated rifting between Seychelles and India.


Source: Chatterjee- Proc 30th Int. Geol. Congr. Vol 26, pp - 31-54

The crater is now broken up along the rift. Part of the structure lies along the Indian west coast and part of it along the Seychelles margin.

The argument is at present based mostly on the geometry and structure of the basins and rifted margins matching what a meteorite hit will produce if it hit the crust at a  shallow angle from the southwest.

But according to what I have read so far there is little direct local evidence of this being an impact crater. There is no core recovered from the supposed impact site and so no information available on whether the features that are seen at the Chicxulub crater in Mexico i.e. impact melt rock, high pressure quartz phases, chaotic breccia,  tsunami deposits and so on are present at this site too.  Also Chatterjee has not given as far as I know a convincing account of why various models of continental rifting, flood volcanism and denudational isostacy are inadequate explanations of the continental margin geology of west India and the Seychelles.

Yet, end Cretaceous always fascinates.

Chatterjee think this impact occurred either simultaneously with the Chicxulub impact or it post-dates the impact in Mexico. I found this view point very interesting for the response it drew from Gerta Keller who is a strong proponent of the theory that the Chicxulub impact was not the primary cause of the K-T extinction. She is pushing for the Deccan volcanics being the real culprit.

Keller has been quoted rejecting Chatterjee's theory, saying there is no evidence for such an impact in Indian deposits. But she leaves a big question unanswered, one that is prompted by her own work and theory.

How do you explain the iridium anomaly associated with many K-T boundary sediments?

Keller contends that the Chicxulub impact took place about 300,000 years before the K-T boundary (read the debate here). The iridium anomaly at the K-T boundary is widely acknowledged - including Keller - to be of meteorite impact origin. In a previous paper she has proposed the possibility of multiple impacts to account for this iridium anomaly, even naming the Shiva crater as a potential candidate for a second impact site.

Now she seems to be against the Shiva impact theory and cites a lack of local evidence in Indian continental deposits for the Shiva impact event, but see....let me add an intriguing possibility... the Deccan volcanics complicate the stratigraphy and everything depends on the exact timing of the impact.  If the impact did not coincide with deposition of sediments and instead took place during eruptions, then all that evidence could be lost..obliterated within the lava flows. At end Cretaceous in the Indian continent these events, volcanism and sedimentation phases, alternated over periods of tens to a few hundred thousand years, and how can one be sure if the impact didn't coincide with a period of non-deposition and volcanism?

Given Keller's strong stance that there was no single smoking gun for the K-T mass extinction its a little bizarre that she is now dissing Chatterjee's hypothesis so readily and apparently rooting for the Deccan volcanics as the smoking gun!

So one impact definitely but how many more? ...still unanswered..

The most sympathetic view of Chatterjee's hypothesis was from The Economist who suggested that if the Shiva impact post-dates the Chicxulub impact, there should be two stratigraphically separated iridium enriched layers. The article pointed out to the Anjar deposits in west India as a site which might contain these two iridium anomalies.

I followed up on the work on the Anjar sediments. These are lacustrine (lake deposits)  inter-trappean sediments i.e. they are sandwiched between Deccan volcanic layers. Magnetostratigraphy indicates the sediments to be deposited in the latest Maastrichtian (the uppermost division of the Cretaceous) within the magnetic zone 29R (R- reversed magnetic field), which contains the K-T boundary at many locales. There are three iridium enriched layers each occurring below a clay rich bed.

Sounds like an ideal candidate in support of multiple impacts.

...Except there seems to be no evidence that these iridium anomalies are due to meteorite impacts or that they encompass the K-T boundary. Geochemical analysis shows that the section lacks the negative carbon isotope excursion that is characteristic of the K-T event found in terrestrial deposits elsewhere (see here). There is evidence in the form of high temperature low pressure cristobalite ( a variety of quartz) in the clay beds associated with the iridium (see here) that these could represent leaching and enrichment from a alkali volcanic tuff. Impact deposits should contain high pressure varieties of quartz.

Early alkali Deccan volcanics along the western margin of the rifted Indian continent are known to be enriched in iridium (see here) and leaching and secondary enrichment could form concentrated iridium layers.

Finally the sediment above the iridium enriched layers contain dinosaur egg shells and late Cretaceous ostracods (see here). Along with sedimentological features this indicates that the iridium layers at Anjar  predate the K-T extinction significantly and were formed in the early part of magnetic cron 29R.

It does not appear that these particular iridium layers are a result of the Shiva impact if it did occur. These deposits are well within the impact fallout zone for the Shiva impact and should have contained direct impact evidence like shocked quartz.

So....looks like many iridium layers but not all of them associated with the K-T boundary or with meteor impacts. 

The Chicxulub impact and the Deccan volcanism overlapped. The stratigraphy of end Cretaceous is going to be messy and it won't be possible to sort out events that took place with a few tens of thousands of years of each other and tie them to either an impact or volcanism. If there was a second impact its record could easily be amalgamated with that of volcanism and very hard to resolve within Indian continental deposits as an independent event .

Direct drilling and study of the recovered core from the Bombay High basin basement which is supposed to be the impact site should decide the issue

...if and when that data comes around.

My head is reeling with these details and nuances. I'll leave readers to sort through the evidence.

Wednesday, October 28, 2009

Cambrian Explosion: This Time Its The Calcium That Did It

Geological processes and evolution - 4

A short article in Science Daily describes research that suggests that a buildup of calcium in the oceans in the early Cambrian provided the necessary trigger for the Cambrian "explosion" - the pronounced expansion and diversification of multicellular groups of animals. Some of the best examples of this evolutionary radiation is preserved in deposits like the Burgess Shale and the Chengjiang strata.

Here is the one sentence summary-

The researchers succeeded to show that the massive and sudden surge in the calcium concentration of the Cambrian seawater -- that is believed to be the result of volcanically active mid-ocean ridges -- not only initiated the buildup of calcified shells, but was also mandatory for the aggregation and stabilization of multicellular sponge structures. This allows, on the other hand, to formulate a novel theory where the geologically induced increase of marine calcium might be the key for understanding the Cambrian Explosion of Life.

There is deja vu when I read another ultimate causative explanation for the Cambrian explosion. Over the years you could write a similar sentence but substitute the word calcium with the sudden increase in oxygen, the warming of the earth following the thawing of the snowball earth, the increase in shallow shelf areas following marine transgression, all proposed as a one point explanations of this evolutionary phase in earth history.

Reading the press release you get a sense that the Cambrian explosion coincided with the origin of multicelluarity. Take this sentence:

However, the causes of its origin have been the subject of debate for decades, and the question of what was the trigger for the single cell microorganisms to assemble and organize into multicellular organisms has remained unanswered until now.

Its important to make a distinction here between the origin of a system and its subsequent diversification. Groups like fungi, plants and animals have evolved multicellularity independently of each other.  Whatever triggered single celled animals to assemble into multicellular ones (metazoans), that transition did not happen in the Cambrian but much before in the late Proterozoic maybe as much as 50 -100 million years before.

The original study recognizes this point but it gets lost in the press release.

There is a good and improving fossil record of metazoans from the late Proterozoic Ediacaran fauna and other types of fossil preservation that indicates that  molecular mechanisms for cell to cell signaling and cell adhesion must have evolved well before the Cambrian. Multicellularity in animals originated long before the Cambrian explosion occurred and long before the rise of calcium in Cambrian sea-water.

The figure below summarizes the current fossil record of the evolution of metazoans. The Cambrian "explosion" corresponds with the Chengjiang fauna.



 Source: On The Origin of Phyla

Explanations of the origin of metazoans and subsequent evolutionary radiations like the Cambrian explosion involve long and intertwined causal chains. A rise in oxygen by late Proterozoic may have favored larger body size and one solution to achieve this large size was to aggregate into colonies of cells which eventually became integrated as one organism. The marine transgressions by late-Proterozoic early Cambrian expanded available shallow marine shelf areas and created large and diverse ecologic niches for evolutionary diversification to take place. The evolution of predation would have set forth selective pressures for skeletonization.  Many organisms would have taken opportunistic advantage of the rise of calcium in sea-water to boost skeletal production. Likewise calcium may have provided stability for even larger masses of cells to aggregate.

There were many geological and ecological factors at play feeding of each other that were responsible for one of the major transitions in the history of life. Insisting on just one cause as the most important to the exclusion of others is too simplistic.

Saturday, October 24, 2009

The Latest Numbers On Arctic Oil and Gas Potential

Some interesting readings I came across on hydrocarbon resources and challenges over the last few days.

Geology.com has published a report by the Energy Information Administration on the latest estimates of undiscovered technically recoverable oil and gas resources of the Arctic basins.

And the number is large - about 400 billion barrels of oil equivalent or about 20 odd percent of the world's undiscovered resources. This is an estimate based on occurrence of geologically favorable conditions in various Arctic basins. These are resources or potential. They will be or rather a fraction of these will be added to reserves only when someone drills and more directly estimates the amount of hydrocarbons that can be economically recovered.

We won't be running out of oil and gas or other fossil fuels like coal soon,  geologically, and BP's chief executive officer Tony Hayward thinks that in 2030 fossil fuels will still be meeting 80% of the world's energy needs.  He explains his position in a speech given at the Oil and Money conference, London. The title of the conference conjures up images of greedy petro-oligarchs doing everything to maintain a vice-like grip on the supremacy of fossil fuels, but the changeover to renewables won't be easy given the enormous gap that exists between the contributions from fossil fuels and renewables to our energy mix. India for example generates 70% of its electricity from coal and has plans to build plenty of coal fired power plants in the near future. The contribution of solar and wind to power generation in India is currently negligible. The U.S generates about 46% of power from coal and the contribution of non-hydro renewables to power generation is just 3%.

If fossil fuels are going to be an important if slowly declining part of our energy mix for some time to come then Geoffrey Styles of Energy Outlook argues that we rethink our reluctance to pursue low emissions strategies like carbon capture and sequestration (CCS). He writes on not just the technological and economic challenges facing CCS but also a public backlash against it based on  - he thinks - a lack of education among the public about geological principles and the efficacy and safety of CCS.

Plenty to think about as the Copenhagen climate change summit nears.

Wednesday, October 21, 2009

How Much Oil Underneath?

A friend asked me a few days ago why the Karnataka government were giving two different estimates for iron ore potential in the state. One file says that the iron ore reserves are about 3,447 million tonnes, while another department file says that the state has about 9,000 million tonnes of iron ore resources.

I replied that assuming the Karnataka government is using the words as they are commonly used in industry, reserves are the fraction of resources that can be economically exploited at any given time. Neither is a static quantity. Both will change given new finds, technological breakthroughs that enable recovery of previously out of bound deposits and the economic and political climate.

Coincidentally Scientific American has an article in their recent issue on the current reserves of oil and how that quantity is changing with new finds and new technology. They give one example:

When Kern River Oil Field was discovered in 1899, analysts thought that only 10 percent of its unusually viscous crude could be recovered. In 1942, after more than four decades of modest production, the field was estimated to still hold 54 million barrels of recoverable oil, a fraction of the 278 million barrels already recovered. “In the next 44 years, it produced not 54 [million barrels] but 736 million barrels, and it had another 970 million barrels remaining,” energy guru Morris Adelman noted in 1995. But even this estimate proved wrong. In November 2007 U.S. oil giant Chevron, by then the field’s operator, announced that cumulative production had reached two billion barrels. Today Kern River still puts out nearly 80,000 barrels per day, and the state of California estimates its remaining reserves to be about 627 million barrels.

This story will apply to a wide range of mineral/oil deposits all over the world.  Famously the United States has produced a cumulative 200 billion barrels of oil from reserves that never at any one time exceeded 40 billion barrels.

In the many responses to the Scientific American article I thought this one from JR Wakefield stood out as it explains what peak oil means from different perspectives:

Its not about how much oil is in the ground, it's how fast you can get it out and at what net energy.  This thus article is highly misleading.   Here are the Five Horsemen of Peak Oil:

1) Geological Peak. That is the point where we have consumed half the oil in the ground. So far we have consumed a trillion barrels. Estimates of remaining oil range, but the number appears to be 3 trillion barrels remaining in the ground. So we are not at geological peak. Hence skeptics of peak oil use this for their arguments, like this SA article does.

2) Flow Rate Peak. That's the point at which you cannot extract the oil fast enough to meet demand. This is especially so with old fields in decline (which is a fact) and new fields which have difficult geology (like this one).  The flow rate from them does not keep up with decline, nor keep up with growing demand. The article failed to mention that North Sea is all in terminal decline and the UK has to now import oil. Indonesia peaked years ago and has to import oil forcing them out of OPEC.  The Cantarell field in Mexico, the third largest in the world, and the US's 3rd import source, was producing 2.3mb/day at it's height.  Today it's 560kb/day with a 41% drop from last year.  WE ARE AT FLOW RATE PEAK NOW.

3) Geopolitical Peak. That's when exporting countries, due to their own growing demand, decide not to sell their oil abroad any longer but decide to keep what's in the ground for their own future domestic needs. So far only the US does this, but expect other countries to soon follow that.

4) ERoEI peak. This is the point at which it takes as many joules to extract the oil than you get from the oil extracted. That is, one barrel in to get 1 barrel out. Conventional wells in the 1960s were 100:1. That has dropped to about 25:1 today. Aging fields and new unconventional fields have very low ERoEI. The tar sands in Alberta for example is less than 6:1. Our entire society is based on the NET energy, not what's extractable. Calculations show that we will reach over all break even in oil extraction between 2020 and 2030. Once that is reached it basically means we have completely run out of oil.

5) economic peak.  This is the point where the economy cannot tollerate high oil prices and plunges the world into a recession, like this one which was caused by $140.barrel oil.

The challenge before us in terms of combating global warming is to ensure a transition from hydrocarbon energy to low emissions renewable energy much much before we start running out of the stuff not just in geological terms - which is not going to occur anytime soon - but by the other measures like Flow Rate and ERoEI as well. Likely even the Flow Rate Peak and the ERoEI peak are not constant but will keep shifting as more efficient ways of extracting oil and other hydrocarbon resources are discovered.

Monday, October 19, 2009

The Probability Of Evolutionary Pathways

Joe Thornton of the University of Oregon and the Howard Hughes Medical Institute writes these thoughts about how to understand and appreciate the probability of evolution following one specific pathway among many possible:

Consider the future: there are countless possible that could emerge from our present state, making the probability of the one that actually does evolve extraordinarily  low.  Does this mean that the future state that will ultimately emerge is  impossible?  Obviously not.  To say that our present biology did not evolve  deterministically means simply that other states could have evolved instead; it does not imply that it did not evolve.

Consider your own life history as an analogy.  We can all look back at the road  we have traveled and identify chance events that had profound effects on how our lives turned out.  “If the movie I wanted to see that night when I was 25 hadn’t been sold out,  I never would have gone to that party at my friend’s house, where I met my future spouse….”  Everyone can tell a story like this.  The probability of the life we actually lead is extraordinarily small.  That obviously doesn’t mean that its historical unfolding was impossible.

That we inhabit an improbably reality requires a divine explanation only if we, like Behe, take the teleological view that this is the only reality that could exist.  But if we recognize that the present is one of  many possibilities, then there is no difficulty reconciling the nature of  evolutionary processes with the complexity of biological forms. As history unfolds, potential pathways to different futures are constantly opening and  closing. Darwinian processes are entirely adequate to move living forms  along these pathways to a remarkable realization – but just one realization out of many others that could have, but didn’t, take place.

Beautifully written.

The entire article is worth reading as it explains how complex traits with interlocking components can evolve through a combination of natural selection and random genetic drift acting on adaptive mutations and neutral intermediates. And this is not just theory. Joe Thornton leads a team that does experiments to show how this can happen. The article encapsulates modern evolutionary thinking about the evolution of complexity quite well.

That it is a devastating put down of the arguments made by the Intelligent Design community makes it especially pleasurable to read. 

Friday, October 16, 2009

A 20 Million Year History Of Atmospheric CO2

From Brave Blue Words I found out a day late that yesterday was Blog Action Day for Climate Change. Bloggers all over the world are writing about various aspects of climate change.

Being a geologist I want to point to a study that reconstructs atmospheric CO2 levels as far back as the Miocene  - a 20 million year history. Atmospheric CO2 levels have been reconstructed with some confidence for the last 800,000 years or so using gas bubbles trapped in the Antarctic ice sheets. Before that the data was thin.

Aradhna Tripati and colleagues have used the boron to calcium ratio in foraminifera shells to calculate ancient CO2 levels. As atmospheric CO2 increases some of it diffuses into the ocean increasing the dissolved CO2 content of sea-water. That in turn reduces the amount of boron that is incorporated in a growing calcium carbonate shell of the foraminifer individual. The variation in the boron to calcium ratio over time as recorded in foraminfera fossils of different ages should tell us something about transitions in CO2 levels.

The scientists first validated their calculations using the 800 K record of CO2 trapped in ice. They compared their results with those obtained by the direct measurement of CO2 trapped in gas bubbles. It was a good match. The scientists calculate that the uncertainty in their results is about 14 parts per million.

Their results show that there is a close coupling between CO2 levels, sea-level and temperature over the last 20 million years.  In the middle Miocene (~ 20 ma) CO2 levels were about 400 ppm - comparable to modern levels - and that sea-levels at that time were 30 -40 meters higher than today (geologists estimate this using distribution of ancient shorelines), with temperatures about 3-6 deg C higher (using geochemical proxies like the oxygen isotope composition of shells which depend partly on temperature of the water from which they precipitate). Decreases in CO2 levels in the later part of Miocene and Pliocene were synchronous with major episodes of cooling and glacial expansion.

Its important to establish that historical connection to answer doubts expressed on what exact impact would increasing levels of CO2 have on climate and sea-level. Many climate change doubters are not happy with computer simulations and models of CO2 increase and climate change. This study shows that CO2 has been a strong driver and amplifier of climate change in the deep geological past. History is also a guide and often a reliable one.

Go here for the press release.A minor quibble. The press release calls the shells used by the scientists as belonging to single celled marine algae. Foraminifera are not algae. They are protists.

Wednesday, October 14, 2009

A Government Scientist Speaks Out On Flood Management

You don't hear many Indian Government scientists opining about science, policy, the environment, civic criticism...well you get the picture.

There are restraints....to put it politely.

But Chetan Pandit of the Central Water Commission has broken the shackles and in the October issue of Current Science comes out sparring strongly against - in his opinion - the woolly headed arguments of the environmental community  and the media on the subject of big dams and flood control.

He puts forth several fallacies and myths regarding dams and flood control and argues very well that big dams have served as effective flood managers.

And I had to chuckle at this:

We Indians seem to be particularly susceptible to this ‘romancing with the past’. Everything, be it water management, or agriculture, Ayurveda, mathematics, literature, astrology, etc., we like to believe that in India all learning had reached its peak in some distant past, and the best thing for us to do is, to continue to do what our ancestor’s did. And this is given a lofty name ‘wisdom of the centuries’.

You may be inclined to view big dams as destroyers of forests and biodiversity and so on but Chetan Pandit has made some good points about the intellectual environment in which debates on these issues take place and are presented to the public in India. One of the most important points he makes is that many people who get involved in criticizing government projects are numerically challenged. Arguments are high on the emotional quotient but there is little quantitative analysis of data to go with it.

I am sure not all environmentalists are so mathematically naive, nor should every developmental project be reduced to just numbers. But this is a government scientists view. When presented with a  rare opportunity to speak out he doesn't restraint himself.

Read the article here.

Update: Chetan Pandit via an email to me wants to clarify:

I never said that those criticizing government projects are “numerically challenged”, or mathematically naïve, etc. Even a high school student would be able to import the data on flood affected area into a spread sheet and plot a graph to see whether or not there is any increasing trend. What happens is, if they do that their argument will collapse, the numbers do not favour them, they know it, and therefore they have to willfully ignore the numbers. Which is why I wouldn’t describe the environment in which debate takes place as “intellectual”. It is pseudo-intellectual.

Chetan Pandit

Sure, he didn't use the words numerically challenged and mathematically naive. Those are my words but he does imply this. For example he writes about noted anti-dam activist Shripad Dharmadhikary -

In his exhaustive critique of the Bhakra dam, noted anti-dam activist Shripad Dharmadhikary writes, ‘Even after the Sutluj flows were augmented by the transfer of Beas water into the Bhakra reservoir, the reservoir has not filled up in most of the years’4. This was probably intended as a critical comment on filling of the Bhakra reservoir. But its implication, which probably escaped Dharmadhikary, is – Bhakra is very successful in flood control. In the years, the dam did not even fill; it is obvious that all the floods were absorbed 100%. And this, despite transfer of a substantial quantity of water from Beas to Sutlej through the Beas–Sutlej link.

But its implication, which probably escaped Dharmadhikary,...

So I read this as meaning Dharmadhikary did not understand the topic well enough. It certainly doesn't read as meaning that Dharmadhikary churned out the numbers, didn't like what he saw and then ignored the finding.

Monday, October 12, 2009

Dinosaur Eggs And Some Stratigraphic Thoughts

The discovery of dinosaur eggs from Cretaceous fluvial sediments near the village of Ariyalur in the state of Tamil Nadu , South India is getting lots of press cover ...here and here. Hundreds have been found in clusters of about 8 over an area of about 2 sq km. Looks likely to be a nesting site. On a sadder note I read in the Times of India a few days ago that there has been no protection given to the site by the government despite requests from the scientists. Locals are already taking away the fossils eggs and disturbing and damaging the site in the process. What a shame!

There also has been some silly press coverage calling this a Jurassic treasure trove, a  holdover of the popular link between anything dinosaur and the word Jurassic....as in Jurassic Park the movie. This particular south Indian sedimentary basin does not have Jurassic sediments. It contains an Early Cretaceous to Early Cenozoic sequence.

What caught my eye was that the sedimentary layer containing the eggs were capped by a volcanic layer. The scientists from Periyar University, Salem, seem to think that this volcanism represents the Deccan volcanic activity dated to around 65 million years ago and that the field relationship between the volcanic layer and the underlying sediment could suggest that this particular volcanic event may have killed or damaged those eggs.

I don't know enough details about the deposit to answer that with certainty but I did have some random thoughts on event deposits i.e layers deposited almost instantaneously and how geologists use such deposits to ascertain the age of the associated sediments. In this case they suggest that sedimentation and the volcanism took place in quick succession and by quick I mean volcanism took place immediately after the dinosaurs laid those eggs....before those eggs hatched.

If a sediment unit is capped by a volcanic layer that is dated to say 65 ma (million years old) then that would mean that the sediment cannot be younger than 65 ma. But does the relationship mean that the sediment too is 65 ma? And what does it mean when you say the sediment is 65 ma. How much 65 ma plus minus ...years, or uncertainty is there in a calculation like this? 

Lets say we get lucky and that the sediment layer is sandwiched between two volcanic layers that can be dated with radiometric methods. Let's say both layers give a date of 65 ma. What does that tell you? Radiometric dates that old come with a sizable uncertainty on the order of hundred thousand years or so. That means the date of the overlying layer might come out as say 65 ma with an uncertainty of 300 thousand years. The date of the layer underlying the sediment may come out say 65.2 ma with an uncertainty of 300 thousand years. The two dates are statistically unresolvable. So even if the sediment is sandwiched between two volcanic layers that indicate the same statistical date there could still be a time lag of tens to a hundred thousand years or so between the sediment being deposited and the volcanic activity.

Fossils are not much use either for this purpose.  Fossils can eliminate the possibility that the events took place in quick succession if the sediment contains fossils which are obviously much older that 65 ma. But again fossil species have temporal ranges of a hundred thousand years or more. Even if the sediment underlying the volcanic layer contains fossils that are indicative in this case of the latest Maastrichtian age (close to 65 ma) there will be an uncertainly of tens of thousands of years and so their presence won't resolve events taking place on smaller time scales.

Geologists have then to rely on the detailed physical relationship within and between the sediment and the volcanic material.

Preserved sedimentary layers are mostly time averaged deposits. That means that material at the bottom of a particular bed is not necessarily older than the material in the upper part of the same layer. During deposition waves and currents keep reworking the same bundle of sediment. Animals may burrow into it and churn up sediment. Material at the bottom part may get transported to the upper part of the layer. The layers thus becomes time-averaged. Organisms who have lived at different times through that depositional episode are all distributed randomly - with respect to their age - throughout the deposit.

A good recent example of a time averaged deposit is the sediment unit that contains the remains of Ardipithecus ramidus the early hominin found in Ethiopia. Scientists lucked out there and realized that the sediment is sandwiched between two volcanic layers dated to about 4.4 ma. Each layer differed in their radiometric age by about 30 thousand years with an uncertainty of about 75 thousand years. Based on this information and the internal characters of the layers the scientists concluded that the geological unit was a time averaged deposit representing a few thousand years of deposition.

This layer containing the dinosaur eggs does not have the characters of a time averaged deposit at least not one representing hundreds or thousands of years. The eggs were found in clusters of 7-8 eggs per nest and these nests are found in successive layers of the sequence. These two indicators suggest that the sediment was not disturbed much. Rather the setting, fluvial floodplains would have meant that the eggs were buried rapidly and entombed during seasonal floods, sorts of event deposits just like volcanic eruptions. That may have been the main cause of the eggs not hatching. The layers immediately underlying the volcanic cap may thus represent sedimentation taking place over a few tens of years, each nest bearing layer essentially preserving or freezing ecosystem conditions as they existed at that time. There is the possibility that the uppermost layer containing eggs represents maybe the last egg laying season before the eruption.

Volcanism when it occurred would have sealed the deposit from further damage from the elements. How close in time was that event to the last egg laying season? Again the scientists will have to look closely at the relationships. Are the eggs in the uppermost layers caked with volcanic ash? Do they show signs of being baked or cracked due to heat, a kind of a Cretaceous hard boiled feast?

Detailed sedimentology and stratigraphy will provide more clarity than absolute radiometric dating and fossil ranges when posed with questions of this nature.