Thursday, July 31, 2008
These days you can see the rocks properties of the aquifer at construction sites which excavate huge holes in the ground to put building foundations. The image below is taken at a construction site on flat ground and shows a very different profile than the first example.
The image shows a thick mature soil grading into a highly weathered basalt at the base. This highly weathered basalt forms the upper part of the aquifer. The weathered basalt grades into fresh basalt which may have horizontal joints like the one in the first photo or may be a more dense compact basalt with vertical joints. Its hard to find a location which shows the entire sequence and I have started taking my camera with me in the hope that a big construction site will show the entire aquifer profile. Meanwhile the figure below depicts the typical shallow aquifer system seen in the Deccan volcanic province.
I think its a lousy and dangerous idea to use this shallow water resource in the manner PMC is proposing to. The corporation simply intends to sink tube wells and install hand pumps and let citizens especially those living in slums access to this water without making any provisions for checking its quality. Unfortunately we know very little about the quality of this water. Likely sources of contamination are leaking and broken sewage pipes and seepage of surface pollutants.The section on groundwater in the environmental status report of the PMC shows that the water has not been screened for the presence of metals, microbes and even fecal matter which is very likely present especially in the groundwater underneath slums which often have no sanitation facilities. Without proper treatment any use of the water in the shallow aquifer constitutes a health hazard.
Pune is luckier than most big cities in India in having an adequate water supply during normal monsoon years. The PMC claims to supply about 200 liters per capita per day. This is much more than most cities in India. There are several big surface reservoirs with capacity to meet projected demands over the next few decades. Pune is growing fast and the problem in recent years has been the delays in setting up water supply infrastructure. Construction of water supply pipelines lags behind buildings, sometimes by years. Suburbs and shanty towns come up either without piped water facilities or with pipes too narrow to supply adequate water, leaving citizens dependent on groundwater which they extract from the deeper aquifer (100 feet or more) or buy from providers who tap it.
But the wild card in coming decades is the reliability of the monsoons. If rains become erratic due to climate change then Pune may be forced into tapping the shallow groundwater system to supplement surface water. This should not be done haphazardly like the current proposal. There needs to be a science backed plan which regulates not only the quality of water taken but also strikes a balance between extraction and replenishment. The deeper aquifer is already showing signs of degrading as unregulated extraction has resulted in an overdraft of several meters over the last decade. That means extraction exceeds natural replenishment with the result that ground water levels are falling year after year. The shallow aquifer if similarly exploited will also diminish quickly as a water resource.
Friday, July 25, 2008
Almost a year ago I wrote a series of posts on air pollution and environmental problems facing Pune City. At that time my blog was virtually anonymous. A few friends knew I had started blogging, but the site meter counter moved only occasionally. Still, I like writing about science and I was curious about air pollution in Pune and I kept writing. I really had no expectations about the reach and effect those posts might have. I had underestimated badly the power of the Internet search:
how much CO2 emitted during vehicle idling
bus pollution graphs
comparing diesel and CNG emissions
forest CO2 sinks
These search phrases I can say changed the profile of my blog. I have had several thousand hits on those Pune City posts and hundreds of clicks on the images of the graphs and tables, which have most likely been downloaded. If at least part of the role of a science blog is outreach and education, then I am satisfied with the role my blog is playing. Last month a reporter from Times of India stumbled upon those posts and interviewed me. The article was published today. I don't expect editorial control over the content of the article, but I wish a draft had been sent to me before publishing. The article covers only one of the posts I wrote and I felt a broader coverage of my posts would have helped highlight the entire series. I think its best readers refer to my posts on these topics. Links below:
Part1. Idling and Pollution
Part2. PMT buses and Pollution
Part3. Rickshaws and Pollution
Part 4. Urban Forests and Clean Air
Part 5. Sensing Corruption Remotely
Part 6. Diets, Consumption and Global Warming
I like writing about the city I live in and the neighborhood I grew up in. Being profiled like this is always welcome but I will keep writing about local issues regardless.
Monday, July 21, 2008
In the landmark study, published by the Paleontological Association, experts unveiled an extraordinary prehistoric lizard-like "flying" reptile which lived 235 million years ago. The scientific community believes that birds descended from reptiles 50 million years later making the kuehneosaurs the world's first "bird".
The long-extinct species, which inhabited the warm late Triassic period from 235 to 200 million years ago, was first discovered in the UK.
According to experts, the kuehneosaurs, which grew up to 2 feet, used extensions of their ribs to form large gliding surfaces on the sides of their body.
What has been discovered is not really a creature with true powered flight, but one which used extensions to form gliding surfaces, similar to the present day "flying" squirrels. True powered flight in vertebrates first evolved in the Pterosaurs, which really are true flying reptiles. But that is not what is deeply wrong with this report. This is a classic example of the much discredited but still popular thinking about evolution as a linear process. This mistaken view goes as follows; This creature is a reptile and it flew. Birds evolved from reptiles about 50 million years later than this creature lived. Therefore this creature is the first bird. But evolution generates not a ladder but a tree like structure. Kuehneosaurs and birds occupy widely separate branches on the reptile tree. All branches of the reptile tree did not transform into birds. Below is a phylogenetic tree of the diapsids, the group of reptiles that contain birds.
Source: Tree of Life Web
Kuehneosaurs or the "flying"reptiles which are the subject of this study are an extinct group within the Lepidosauromorpha. Birds on the other hand are a group within the Archosauromorpha. Although they lived and "flew" before birds evolved, Kuehnosaurs do not occupy an ancestral position with respect to birds. The best evidence indicates that birds evolved from within the maniraptors, a group of small carnivorous dinosaurs on a branch evolutionarily distant from the Keuhneosaurs. Every reptile that flew is not a bird. Flight, as has been the case many times in the history of life, evolved independently in the Keuhnosaurs , Pterosaurs and in birds.
I saved for the last another really silly aspect of reporting that is becoming quite common in the Indian media eager - or maybe desperate is a better word - to portray Indian achievements. This is how the report in TOI begins;
A group of scientists, including one of Indian origin, has discovered "world's first bird" that lived 235 million years ago.
The emphasis is mine. Did we need to know that? Does it make the report more believable? Does it make every Indian reading this puff up their chests with pride? I don't know about you but I find it plain irritating and infantile of the media to keep slipping these "Indian" achievements down my throat. I checked the abstract to find out about this "Indian" connection. The paper title reads: “The aerodynamics of the British Late Triassic Kuehneosauridae” by Koen Stein, Colin Palmer, Pamela G. Gill and Michael J. Benton and is published in the July 15th issue of Palaeontology. Ms. Gill comes closest to being the Indian origin candidate most likely having a Punjabi ancestry, but I mean who cares?? Not the author I bet. Instead why not spend a little more time understanding reptilian evolution? TOI just might come up with a more readable news report.
Thursday, July 17, 2008
The picture I have displayed on the banner was at the end of the wilderness section of the trip. Six days before I took the picture I was on the other side of the craggy peaks, and you get an idea of what I am talking about. 70 miles in six days and having crossed Stoney Indian pass at around 8000 feet (see map below) we were at Goat Haunt waiting for the ferry to take us to Waterton. We could have trekked that last section too, but a hot shower was too much to resist and I jumped on the ferry.
Source: National Park Service
Glacier National Park is one of the underrated jewels of the American National Park system. Maybe its the remote location in Montana near the border with Canada, but even in the height of holiday season, there is no sign of the bumper to bumper traffic that plagues Yosemite, Yellowstone and the Smokies. There is a new threat though of climate change and receding glaciers. There were 150 of them in 1850. Today only 26 remain and shrinking fast. The National Park service has some podcasts of climate related research which are worth a listen. I recommend a visit to the park, preferably soon to catch the last of the glaciers. I want to go there again. Maybe on this future visit I will take the time to look at some of the geology.
Wednesday, July 16, 2008
Here is the list:
8 th sept 2008 - 7.2 on Richter scale
10 th sept 2008 -7.3 on Richter scale
15/ 16 th sept 2008 - 7.5 Richter scale
He is not able to give locations but is apparently working on fine tuning his predictions. As September rolls along I will keep you posted :-)
Update: Was September 08 Earthquake Month?
Saturday, July 12, 2008
The transition from single celled to multi-celled organisms required that there be a complex system of cell signalling proteins for information to be passed from one cell to another. But how can multi-celled organisms evolve without these proteins and why would single celled organisms posses such molecules? A molecular study of single celled choanoflagellates, whose ancient ancestors most likely gave rise to multi-celluar animals have been found to possess three gene markers for cell to cell signalling proteins that are active in multi-cellular organisms. Researchers suspect that in these single celled organisms the signalling proteins play similar but different roles and were co-opted by evolution for signalling purposes during the evolution of multi-cellularity. Evolution tinkers around, building complex parts from what is lying around, moulding existing parts to serve new functions.
Fossils too occasionally throw up fine examples of transformation from one form to another. Flatfish which lie on sandy sea bottoms have both eyes on one side of the head staring into the water column above. Their ancestors presumable had a symmetrical eye arrangement, but evolution doubters argue what good is a slightly asymmetrical head which retains eyes of either side of the head. Natural selection could never have produced such slight asymmetry which would give the fish no adaptive advantage. Two recently discovered fossils of ancient Eocene flatfish from museum collections show exactly the beginnings of this partial asymmetry. The eye has begun its journey towards the other side of the head but not quite. A snapshot of an intermediate stage of evolution frozen in a 50 million years old limestone. The asymmetry of flatfish evolved gradually over time. No need for any mysterious mechanisms or sudden spontaneous origins.
Tuesday, July 8, 2008
How can such a massive revision come about and why were geologists so unsure and so off base regarding the age of the Vindhyans? The advantage when working in the Phanerozoic is the presence of fossils. We can use changes in fossil composition to subdivide the geological record into finer time periods which reflect changing ecology's, climates and sea-levels. The PreCambrian, a vast time period ranging from about 4.2 billion years to 542 million years has a very scanty fossil record. This combined with severe metamorphism -especially in the Archean, the earlier part of the PreCambrian- which destroys original sedimentary structures makes paleo-ecological reconstructions difficult. It has been hard to create a meaningful and fine scale subdivision of the rock record that reflects biological evolution and geological changes occurring worldwide. Geologists have been using continent scale thermal and tectonic events that may leave a characteristic and correlatable rock record to subdivide the PreCambrian but such events are far and few between. One such example though is the kimberlite magmatism that affected Peninsular India around 1100 million years ago. This magmatism includes the famous diamond bearing rocks of Panna district, Madhya Pradesh. This activity has left a marker horizon throughout the Peninsular Indian sedimentary basins that is used to identify the base of the NeoProterozoic. Overall, the situation is somewhat alleviated in the Proterozoic, the younger portion of the PreCambrian. Here there are examples of un-metamorphosed sediment from all over the world including India. More detailed studies are finding evidence of evolution preserved as trace fossils and early forms of skeletal organisms, especially in the NeoProterozoic. But the lack of a consistent fossil record has certainly limited the fine scale subdivision of PreCambrian earth history.The report in Science Daily makes it seem as if the much older age proposed has come as a complete surprise. But that is not so. For long the Vindhyans, which are mainly composed of sandstone, shale and limestones were thought to have lacked minerals which could be used for absolute radiometric dating. But that has changed recently. Geo-chronological work on the Vindhyan group has been going on for several years now and many earlier studies have shown that the Vindhyans are much older. Many of this earlier studies had fixed the age of the lower part of the Vindhyans to be around 1600 million years old, leaving the age of the Upper Vindhyans somewhat unresolved. This current work though focuses on the Upper Vindhyans and uses two independent methods as cross-reference. I find the collective evidence quite persuasive. This may turn out to be one of those findings where geology textbooks may have to be altered.
Science Daily also points out some exciting implications of this finding. First, that it removes an objection to the Snowball earth theory, which says that from 790-630 million years ago, the earth was covered with glaciers that extended up to 10 deg of the equator. There is no physical evidence of this carved on the Vindhyans so pushing back the age of the Upper Vindhyans, making them much older than the snowball earth gets rid of this obstacle. Another implied paradigm shift is regarding the timing of the origin of multi cellular animals. Skeletal remains of metazoans begin appearing in the fossil record by 580 million years ago. The accepted date for the origin of metazoans based on fossils and molecular phylogeny is in the NeoProterozoic between 700-600 million years ago, and the body and skeletal fossil record of that and the slightly younger early Cambrian indicates several rapid evolutionary radiations whereby successive grades of complex animals evolved geologically rapidly and filled empty ecologic niches. On the other hand, some studies in the Vindhyans claim preservation of traces and burrows of triploblastic animals in rocks older than 1 billion years ago, dates which were not accepted by many geologists. No body fossils or skeletal remains of metazoans have been found in rocks this old anywhere. If these trace fossils do represent triploblasts then that would push the origin of complex animals much further back in time and implies a much more stately and slow evolution of complexity. In this view much of the evolution of complexity has been cryptic, not revealed by the fossil record perhaps because animals lacked hard skeletons. The relatively sudden appearance of body fossils by late NeoProterozoic -early Cambrian is then a preservation artifact. Animals already had evolved complex body parts, the explosion of fossils simply indicating a new ability to secrete skeletons. This latter view has gained in popularity among some geologists working on the Vindhyans. But the interpretations of the trace fossils from the Vindhyans has been criticized as not indicative of triploblasts, and basically most paleobiologists think that the metazoan body fossil patterns of the NeoProterozoic and early Cambrian are a faithful record of evolutionary history i.e. metazoans arose relatively late in the NeoProterozoic and evolved morphological complexity rapidly thereafter. Now a more reliable geo-chronological framework for the Vindhyans may open up these old findings to better scrutiny.
Tuesday, July 1, 2008
This is a clever statement. It re enforces our commitment to the per-capita method of looking at CO2 emissions, which India has argued is the only equitable way of addressing emissions, but at the same time issues a challenge to developed countries to reduce their emissions as much as possible. It also gives us a huge space to increase our own emissions. Currently per-capita emissions of developed nations average to about 15 tons of CO2 per year. India emits per-capita about 1.3 tons CO2 per year. The G8 have made various pledges to reduce emissions by 60-80% by 2050. Even if they are able to reduce emissions by 50%, an amount considered very optimistic by many, India will theoretically be able to increase its per-capita emissions about 5 fold while maintaining levels below those of the developed nations. Our emissions will most likely not grow that much. The projections are for a 2-3 fold increase in our emissions by 2050 with the business as usual scenario, but might be a lot less (pdf: 8 mb) if we enlarge our energy efficiency and renewable energy programs, both of which feature in the National Action Plan on Climate Change.
We need to look at reducing our CO2 emissions not only from the perspective of combating global warming but all the associated pollution that accompany CO2 emissions. Coal burning power plants, industrial emissions, emissions from transportation are all adding to the rapid growth of sulphate pollution one of the main ingredients of soot. This not only has damaging local health effects but may even impact monsoon patterns. Climate models predict an overall increase in the Indian monsoons over the next several decades, but a recent study shows that an increase in soot also known as brown haze which hangs over the Indian subcontinent may weaken the monsoon by blocking sunlight reaching the Indian ocean. While an uneven increase in rainfall due to a warming trend will come with its own problems, even a short to medium term decrease in overall rainfall might prove to be disastrous for India. Flipping or rather scrolling through the report I noticed that there is not much enthusiasm on carbon capture and storage strategies (CCS) for coal power plants. This is a pity since much of our expansion in power generation in the 11th 5-year plan will be through increased coal plants. I think this is where we should be proactive in pursuing technology transfer for CCS under the Clean Development Mechanism of the Kyoto Protocol. Power generation will account for about 50% of our emissions in 2050 and a shift towards cleaner technologies for coal plants and a larger component of renewable energy in power sector will go a long way in achieving emission reductions.
Reducing these emissions is in our own interest and I hope we don't get too caught up in our "right" to emit as much per-capita as developed countries to ignore the impacts of increasing emissions and associated pollution on our own citizens. We keep making the argument of our per-capita emissions being lower than developed countries but what is never pointed out by the government but has been pointed out by others is that there is a huge disparity in our emissions. Although the average per-capita emissions of an Indian is about 1.3 ton CO2 per year, about 150 million Indians already emit considerably more than the sustainable limit (2.5 tCO2 per year) needed to restrict CO2 levels to about 450 ppm corresponding to about a 2 deg centigrade increase in temperature (this is considered a threshold figure, any temperature increase more than this will increase the risk of catastrophic changes to the climate system). The rest of the 800 million or so emit much less, but this is the section of society which will feel the impacts of local pollution as well as long term climate change the most. If through a scientific evaluation we have come to a consensus cutoff value for our emissions, then an exceeding of that limit by rich Indians is as unjust on poor Indians as exceeding that limit by a rich European. So while we argue for the right to equitable per-capita emissions with developed countries we need to extend the same principle to address disparities in our society.
I am sure there is a lot more to say about various aspects of our response to climate change but this will do for now.