Review Papers: Geodynamical Evolution Of India

Episodes, Journal of International Geoscience, has an open access special issue on the geology of the Indian subcontinent.

Excellent source for teachers, researchers, and curious science lovers.

I liked the paper on Deccan Volcanism a lot, especially the emphasis and attention given to the physical properties of the lava flows, and the problems of correlating (establishing their genetic and temporal relationships) lava sections from different parts of the Deccan Volcanic Province.

I don't know much about the Archean to Neoproterozoic age ( > 2500- 542 million years old)  southern granulite terrain, a region where very high temperature high pressure rocks known as granulites and charnockites are exposed. That is a topic I am looking forward to reading and learning about. The famous Anamudi Peak in the Western Ghats  are made up of these rocks. Geologists suspect that their high altitude is partly a result of differential erosion. Charnockites in particular are harder and have resisted being worn down, resulting in them standing out as high domes.

Another cool paper is on the role of microbial colonies on sedimentation patterns in the Proterozoic sedimentary basins of India (2500-542 million years ago). Microbial colonies grew as mats covering sediment surfaces influencing their accumulation and erosional patterns. Such environments became rare since Cambrian times (542 million years ago) when animals which eat and disrupt microbial colonies evolved.

Dive in.

Papers: Global Tectonics, Cryogenian Period, Himalaya Miocene Lakes

I've come across quite a few interesting papers on diverse topics in the past couple of weeks. Most of them are 'big question' themes, dealing with processes taking place on global scales. Here are the links.

Global Tectonics:

1) Subduction Initiation of the Wilson Cycle - In plate tectonics, the Wilson Cycle refers to cyclical ( frequency of 100's of millions of  years) breakup of continents and the opening and closing of ocean basins. But how is subduction initiated and new convergent plate boundaries formed? Some good examples from the Western Pacific margin and eastern Indonesia.

2) How Subduction Broke Up Pangaea - Was it top down forces.. i.e. the pull exerted by subducting slabs or was it the horizontal traction exerted by a convecting mantle (bottom up) that broke up the supercontinent?

3) Why is Africa Rifting? - Insights into the formation of the famous East Africa rift system.

4) Gondwana Large Igneous Provinces: distribution, diversity and significance - Synopsis of several papers that explore the link between prolonged magmatic episodes, tectonics, climate shifts and sedimentation patterns in Gondwana continents.

Neoproterozoic:

1) Snowball Earth climate dynamics and Cryogenian geology-geobiology - In the Cryogenian Period, between around 715 to 635 million years ago, the earth was blanketed in two prolonged glaciations. Before these glaciations, the earth was a microbial planet. The end of these glaciations is associated with the evolution of multicellular complex life. What were the conditions during the Cryogenian Period that influenced the evolution of life?

Himalaya:

1) Oligocene‐Miocene Great Lakes in the India‐Asia Collision Zone - Mount Kailash is an important pilgrimage site for Hindus. The sediments that make up this mountain were deposited in narrow basins in the India-Asia collision zone. They preserve a record of surface environments and geodynamic mechanisms operating within the suture zone during the convergence of India with Asia.

All Open Access.

Exploring India's Paleogeography And Fossils Using The Paleobiology Database Navigator

I was directed to the Paleobiology Navigator by a tweet from @avinashtn .

Great fun! The Paleobiology Database is being maintained by an international non-governmental group of paleontologists. Contributing members add to it fossil occurrences from scientific publications.  The Paleobiology Database Navigator is a web mapping application managed by the University of Wisconsin-Madison that allows you to explore the geographic context of these fossil locations. You can filter the data based on age, taxonomy and geography. You can also generate diversity trends for the selected set.

I played around a bit with India specific fossil locations.

Paleozoic versus Mesozoic Basins

The figure below shows the distribution of fossil localities for the Paleozoic Era. India is shown as it is today and in its Paleozoic geography.

Source: Paleobiology Navigator

You can clearly see that fossils in Peninsular India are predominantly located in one narrow band in the center and east of the country. These are the Permian Gondwana basins. They are, starting from the westernmost and going eastwards, Satpura Basin, Son Valley Basin, Damodar Valley Basin and the Ranjganj Basin.  These are continental interior basins comprising river, lake and swamp environments. Most of India's coal deposits come from these basins. These basins are rich in plant fossils, and reptile and amphibians remains.

Now take a look at India's geographic position (arrow) during the Permian (298-252 million years ago). Peninsular India occupies an interior location within Gondwanaland, far away from any ocean. Tectonic stability through most of the Paleozoic meant lack of crustal movements. During this time, peninsular India was an erosional landscape until the Permian basin formation in the east.

The one Paleozoic fossil location in Rajasthan shown here represents early Permian marine sediments formed by the flooding of the western region by an arm of the Tethys sea.

And this database has still not added one important fossil location. This is the early Cambrian age locality near Jodhpur where sediments of the Nagaur Group are exposed. They contain trilobite trace fossils.  No basin development and sedimentation took place in Peninsular India from Mid-Cambrian to Permian times (530 million years to 298 million years). 

In contrast, look at the northern edge of India, where the Himalaya stand today. That margin was submerged under the Tethyan ocean. A thick pile of marine sediment accumulated right through the Paleozoic, forming the fossil rich Tethyan Sedimenary Sequence of the Himalaya.

Continental configurations changed in the Mesozoic (252 million to 66 million years ago). The figure below shows Mesozoic fossil locations and the Cretaceous paleogeography of India.

Source: Paleobiology Navigator

There is now a wide swath of fossil localities across Peninsular India. The dotted lines trace important linear depressions where sediments were deposited. The east west oriented Narmada rift zone (NRZ; Jurassic and Cretaceous) and the NW-SE oriented Pranhita Godavari zone (PGR; Triassic to Cretaceous) are important fossil repositories.  The eastern India basins continued accumulating sediment. To the west are the basins which formed in Gujarat and Rajasthan (Jurassic and Cretaceous). The Kutch rift (KR) is outline by dotted lines. And to the south east in Tamil Nadu, marine flooding of the eastern continental margin in the Cretaceous resulted in the deposition of richly fossiliferous sedimentary sequences.

All these basins ultimately owe their origin to the forces exerted on the crust as India pulled away (arrow) from Gondwanaland.  Seaways formed along these rifts and crustal depressions. The Mesozoic, especially the Jurassic and Cretaceous, was a time of global high sea levels. The western margin saw marine incursions from the nascent Indian Ocean, while the eastern margin was submerged by the waters of the newly formed Bay of Bengal.  River and lake systems also developed in more continental interior locations. The northern margin (Himalaya) was mostly a marine environment through the Mesozoic.

Marine versus Continental Interior Basins in Mesozoic Central India

The distribution of terrestrial organisms versus marine organisms can tell us about the extent of marine flooding into Peninsular Central India in the Mesozoic.

I created these maps by using localities of dinosaur fossils (above) to map the distribution of terrestrial sedimentary environments. I used localities of invertebrate marine organisms, namely,  brachiopods, echinoderms and ammonoids  to delimit the extent of marine environments along the Central Indian basins (below).

 Source: Paleobiology Navigator

You can see that terrestrial environments were present right across the Narmada rift zone, the Pranhita Godavari rift basin and in the western Indian basins also. In the western basins, some of the dinosaur fossils have been found in marginal marine settings comprising coastal and estuarine environments.

Deeper water marine environments as evidenced by brachiopod, echinoderm and ammonoid localities are however restricted to Gujarat, Rajasthan and western Madhya Pradesh. The Cretaceous Bagh Beds in Madhya Pradesh is the eastern most limit of Mesozoic marine flooding into Central India. Seaways did not extend into eastern parts of the Narmada rift basins.

Global and Indian Dinosaur Diversity Patterns

I used the Stats tool to create graphs of dinosaur diversity. The number of Genus per Stage is being used as a measure of diversity. Geologic time is subdivided in to bins. An Age is a bin spanning a few million years. Stage represents rock layers deposited in an Age. So, a diversity measure has been created by counting the number of dinosaur genus reported from successive bundles of rock layers, each representing a few million years of time.

Source: Paleobiology Navigator

The global diversity pattern shows episodes of diversification and decline in the Triassic, Jurassic and the Cretaceous. There appears to be a trend of increasing diversity through time with peak diversity in the Mid-Late Cretaceous. The Late Cretaceous extinction of dinosaurs forms the right side boundary.

The diversity measures in India show some differences with global trends. The number of Genus sampled are less. This is due to regional versus global sample. A smaller locale will generally have less of the total observed variation. The trends in diversity with time also is different from the global trajectories. There are a couple of reasons for this. First, this is a preservation artifact. Mesozoic terrestrial basins in India were receiving sediment only episodically. Depositional phases were interrupted by erosional hiatuses. Rock sections thus have been removed as well.   There was little to no sedimentation from Mid-Jurassic to Mid-Cretaceous in the Narmada rift basins. Hence, no fossils either. The lost diversity from this interval is irretrievable.

The second reason gives more hope. A couple of years ago, Dr. Dhananjay Mohabey of the Geological Survey of India gave a talk in Pune on Late Cretaceous dinosaurs of India. He mentioned that there are roomful of dinosaur fossils in government archives that are yet to be studied and catalogued. There is scope then to enhance our understanding of at least late Cretaceous dinosaur diversity of India.

I have barely scratched the surface. There are many more stories and patterns and trends in the Indian fossil record waiting to be teased out from this database. Dive in!

Open Access- History Of Life Articles In Current Biology

Update: November 6 2015- The articles are no longer open access.

This is a treat!

A special section in Current Biology on the History of Life with short essays and longer reviews on a variety of evolutionary history topics. So far I have read four:

The Cambrian Explosion - Derek E.G. Briggs
The Neoproterozoic- Nicholas J Butterfield
Novelty and Innovation in The History Of Life- Douglas H Irwin
Life in the Aftermath of Mass Extinctions- Pincelli Hull


These are densely written and immensely informative articles about various aspects of the evolution of the earth and its biosphere.

Couple of passages-

..from Novelty and Innovation in The History Of Life on the different styles of diversification seen in the fossil record-

Several challenges have arisen to claims that adaptive radiations are responsible for most evolutionary diversifications. For one, many events have been identified among both living and fossil clades that cannot be explained as the outcome of diversification from a single species. Examples range from the Cambrian explosion of animals, which involved many major clades but relatively few species, to the diversification of grasses. I have already discussed cascading radiations where increased diversity was driven by ecological interactions between clades. Other diversifications, for example the spread of a genus across a continent, may be largely non-adaptive. The most striking observation, however, is the absence of evolutionary novelty associated with classic adaptive radiations. Indeed, by their nature, adaptive radiations concern the adaptive exploitation of ecological opportunities via variation on existing adaptive themes, but not the formation of the themes themselves. While the fossil record documents adaptive radiations that encompass greater morphological diversity than Darwin’s finches, mockingbirds or Anolis lizards, including the spread of insects and angiosperms, and the Mesozoic radiation of mammals, the origins of morphological novelties often seem to involve a different process.

..from The Aftermath of Mass Extinctions-

Macroevolution is shaped as much by those who survive as those who did not [3,121]; it is shaped as much by extinction, as by innovation and speciation [3,122]. More than 99% of all the species that have ever lived are now extinct [3], and the losses have often been distinctly non-random [7,8]. The largest biotic crises eliminate entire branches of the tree of life [1], drive the decline of once diverse clades [123], and lead to the radiation of new species and ecosystems [13,124,125]. In the prolonged aftermath, ecosystem change across the globe exerts an evolutionary influence distinct from the extinction itself, with a timing characteristic of the earth system (i.e., earth system succession). As such, mass extinctions should not be considered as macroevolutionary point events, but rather as prolonged intervals of varying selection spanning the mass death and subsequent radiation of taxa.

The last line adds some perspective.... that although mass extinctions are defined by death, there is also evolution, often at elevated rates, going on during this interval. Groups of organisms which are able to adjust and evolve their way through environmental crises will find and occupy emptied ecologic niches and so to speak inherit a new earth to settle and diversify.

As you would have guessed from the articles I first dived into, my interest lies primarily on the broad patterns of evolution as revealed from the fossil record. But there are plenty more biology oriented articles to capture your interest. 

Current Biology

Cartosat 1 DEM- Two Strike Slip Faults

My two favorite strikes slip faults in India as rendered by Cartosat 1 Digital Elevation Model-

1) Yamuna Left Lateral Fault-

Source: Cartosat 1 DEM National Remote Sensing Center, ISRO

You can see that the Siwalik hills are breached by the Yamuna and dislocated in a left lateral sense, i.e. one would have to turn left to follow the narrow marker rock bed across the fault.

From a previous post on this fault-

Miocene onwards a thick wedge of fluvial sediments filled up a foreland basin that formed in front of rising thrust sheets uplifted along the active Main Boundary Thrust (MBT). That phase ended about 0.5 to 1 mya.

This fluvial wedge over the last half a million years has been deformed into the Siwalik mountains. These mountains form broad synclines and tight anticlines cut by north dipping thrust faults, a result of the continuing compression of the sediment wedge. The southernmost of these thrusts which brings into tectonic contact the anticlinal Frontal Range of the Siwaliks over the alluvial plains in called the Himalayan Frontal Thrust (HFT).

The HFT is broken into segments and the amount of displacement along these segments or thrust blocks is unequal. For example the blocks west of the Yamuna and east of the Ganga have moved southwards with an opposite sense of movement relative to the central block known as the Dun block. To view this, turn on labels and pan southeastwards in embeddable map below until the town of Haridwar where the Ganga enters the plains.

Thus the Yamuna fault has a left lateral sense of movement while the Ganga fault has a right lateral sense of movement. These faults can be thought of as lateral ramps of the HFT accommodating the displacement caused by the southwards movement of the HFT blocks. 

Structural considerations indicate that during the last 0.5 my there has been about 8 km of displacement along the Yamuna and Ganga faults, a slip rate of approx. 16 mm year. - See more at: http://suvratk.blogspot.in/2010/12/remotely-india-3-left-lateral-yamuna.html#sthash.H9K4tfrI.dpuf

 Miocene onwards a thick wedge of fluvial sediments filled up a foreland basin that formed in front of rising thrust sheets uplifted along the active Main Boundary Thrust (MBT). That phase ended about 0.5 to 1 mya.

This fluvial wedge over the last half a million years has been deformed into the Siwalik mountains. These mountains form broad synclines and tight anticlines cut by north dipping thrust faults, a result of the continuing compression of the sediment wedge. The southernmost of these thrusts which brings into tectonic contact the anticlinal Frontal Range of the Siwaliks over the alluvial plains in called the Himalayan Frontal Thrust (HFT).

The HFT is broken into segments and the amount of displacement along these segments or thrust blocks is unequal. For example the blocks west of the Yamuna and east of the Ganga have moved southwards with an opposite sense of movement relative to the central block known as the Dun block. To view this, turn on labels and pan southeastwards in embeddable map below until the town of Haridwar where the Ganga enters the plains.

Thus the Yamuna fault has a left lateral sense of movement while the Ganga fault has a right lateral sense of movement. These faults can be thought of as lateral ramps of the HFT accommodating the displacement caused by the southwards movement of the HFT blocks.

Structural considerations indicate that during the last 0.5 my there has been about 8 km of displacement along the Yamuna and Ganga faults, a slip rate of approx. 16 mm year.

The Digital  Elevation Model also brings out beautifully the Quaternary alluvial fans with tiers of river terraces deposited in the valley between the Siwaliks and the Lesser Himalayas and the intricate drainage on the southern slopes of the Siwalik frontal range.

2) Gani Kalava Fault-

This too has a left lateral movement and has a prolonged history of being reactived during different phases of sedimentation in the Proterozoic Cuddapah Basin of south India.  I  did my M.Sc dissertation on this area, concentrating on the asymmetric anticline with a gentler dipping southern limb and a nearly vertical dipping northern limb located south of Gani village.

Source: Cartosat 1 DEM, National  Remote Sensing Center, ISRO

From a previous post on this fault-

The feature is an ENE plunging asymmetric anticline with spectacular dip slopes of quartz arenites making up the southern limb of the fold and left-lateral movement along a regional fault steepening the northern limb of the fold. There is some copper mineralization along the fault. The Cuddapah basin is an intra-cratonic basin which was filled up in several depositional mega cycles. Sections of two of these mega cycles are exposed in this area. The older mega cycle comprising the Cuddapah subgroup is exposed in the core of the anticline. An angular unconformity separates the older cycle from the younger Kurnool cycle (sub group) which is exposed along the limbs.

Brown arrows shows the offset marker beds (grey arrows show sense of movement) of the oldest sedimentary formation of the Cuddapah basin, the early Proterozoic Gulcheru Quartzites and Vempalle limestones of the Papaghani Group. These lie unconformably on the Archean Peninsular  Gneiss which is the fawn colored peneplain in the left part of the DEM. The very distinct dip slopes of  the Gani anticline (south of Gani village) are made up of a much younger sedimentary unit, the Banganpalle  Quartzites of the Kurnool Group. They were deposited in energetic shallow seas, forming a vast sand shelf, wherein waves and currents winnowed out unstable minerals, leaving behind a nearly pure well sorted and rounded quartz sand. The quartz grains are polycyclic, meaning they show evidence of being derived by weathering of older sandstones, the most likely source being the Gulcheru Quartzites.

Remember this is a Digital Elevation Model,  same color means the same altitude range and not mineral composition.

Free Download- Cartosat 1 India 1 Arc Sec Digital Elevation Model

I've been writing periodic updates on Bhuvan and have been critical about some of its features before. Today I sing its praise.

Bhuvan is the Indian Space Research Organization's web mapping portal. It was  launched with much hype in 2009, touted by the media as a Google Earth killer.  That it hasn't turned out to be. Google Earth /Maps is still the most used application for browsing imagery and exploring the world's surface.

This need not have been portrayed by the media as a Google versus Bhuvan competition. I always felt Bhuvan would offer real value by making available India specific natural resources and earth science datasets to overlay imagery. That in fact is the direction Bhuvan has been evolving for the past few years.

Bhuvan now offers a variety of  India datasets for overlay, analysis and download. I have been playing around with the Digital Elevation Model (DEM) derived from Cartosat 1 stereo imagery. The DEM is available as 1 degree tile corresponding to the Survey of India topo map sheets. The interface  to  select and download the DEM is easy to use. Technical documentation of the DEM is also available. Spatial resolution is 1 Arc Sec, which corresponds to around 30 meters. The vertical margin of  error is about 8 meters. Analysis shows that the Cartosat DEM compares well with other widely used DEM such as SRTM (90 m res) and ASTER (30 m res).

Below is  a Digital Elevation Model of the Nallamalai Hills in Andhra Pradesh with a 0.5 deg graticule overlain. I've generated this representation in Manifold GIS. The geological terrain is part of the Proterozoic Cuddapah Basin. Remember, the color scheme assigned to the DEM is not demarcating different rock types but elevation ranges. However, as a nod to the prominent geological feature that I wanted to highlight, I have assigned a color of the common rock in outcrop. These are the Bairenkonda Quartzites and Sandstones of the Nallamalai Group which form folded ridges, part of the Nallamalai fold belt. The green low relief areas are mostly underlain by shales and limestones.

And check out the drainage in color black (lowest elevation). You can make out the drainage divide between the Godavari and Krishna basins. In the upper right part of the image, streams are draining north towards the Godavari river. In the left lower part of the DEM, streams are flowing south towards the Krishna river.

Source: Cartosat 1 DEM, National Remote Sensing Centre, ISRO

I'm planning to tell more stories about Indian geology using these DEM 's. For that I  have to thank ISRO for making this dataset available.

Ocean Acidification- What Exactly Happens?

I've started following @Scitable, an education resource from journal Nature. A few days back they tweeted a link to an article on ocean acidification.

Pay attention-
 
When CO₂ dissolves in seawater to produce aqueous CO₂ (CO_2(aq)) it also forms carbonic acid (H₂CO₃) (Eq. 1; Figure 1). Carbonic acid rapidly dissociates (splits apart) to produce bicarbonate ions (HCO₃^-, Eq. 2). In turn, bicarbonate ions can also dissociate into carbonate ions (CO₃^2-, Eq. 3). Both of these reactions (Eqs. 2, 3) also produce protons (H⁺) and therefore lower the pH of the solution (i.e., the water is now more acidic than it was — recall that pH is the negative logarithm of the proton concentration or activity, -log₁₀[H⁺]. Note, as illustrated in Figure 2, Ocean Acidification does not imply that ocean waters will actually become acidic (i.e., pH < 7.0).

CO_2(aq) + H₂O ↔ H₂CO₃ (1)
H₂CO₃ ↔ HCO₃^- + H⁺ (2)
HCO₃^- ↔ CO₃^2- + H⁺ (3)
 
However, when CO₂ dissoves in seawater it does not fully dissociate into carbonate ions and the number of hydrogen ions produced (and the drop in pH) is therefore smaller than one might expect. This is due to the natural capacity of seawater to buffer against changes in pH, which can be represented simply by:

CO_2(aq) + CO₃^2- + H₂O → 2HCO₃^- (4)

where CO₂ is effectively neutralized by reaction with CO₃^2- to produce HCO₃^-. The HCO₃^- produced by Eq. 4 then partly dissociates (Eq. 3), releasing protons and so decreasing the pH-which is where the ‘ocean acidification' actually comes from-but this drop is much smaller than for an un-buffered system. One can also think of the sequence of events resulting from dissolving CO₂ in seawater as firstly the production of HCO₃^- and H⁺, but because the equilibrium between HCO₃^- and CO₃^2- (Eq. 3) has now been unbalanced by excess acidity (H⁺), Eq. 3 goes to the left to consume some of the excess H⁺, and in doing so, also consumes CO₃^2-.

This is a wonderfully clear explanation of the chemistry of ocean acidification in terms of changing  concentrations or activity of CO2 (atmospheric),  CO2(aqueous), CO3 (carbonate) and bicarbonate (HCO3) ions, as there is later in the article on the negative and positive feedbacks in terms of the capacity of the ocean to absorb CO2 with rising ocean  temperatures.

The proportion of DIC present as CO2 is also affected by temperature, as illustrated in Figure 2. The consequence of this is that, as the ocean warms, less DIC will be partitioned into the form of CO2 (and more as CO32-), hence enhancing the buffering and providing a ‘negative feedback' on rising atmospheric CO2. Here, a feedback describes a mechanism that dimishes or amplifies an initial change and asribed the sign ‘negative' or ‘positive', respectively. For example, melting polar ice caps through global warming will reduce the amount of solar radiation that is reflected back out to space (the Earth's surface becomes less reflective), so producing more warming, which in turn will melt more ice, and so on — a positive feedback. A well-known positive feedback in the carbon cycle arises due to the decrease in solubility of CO2 gas in seawater at higher temperatures. In fact, this greatly outweighs the negative feedback described above, meaning that as the ocean surface warms, even more of the emitted fossil fuel CO2 will remain in the atmosphere.

And how do saturation levels of CO3 in sea water affect the stability of CaCO3 mineral species Aragonite and Calcite which organisms use to build skeletons? What effect will increase in ocean acidification have on organisms? ...

read on.. don't miss out on this chemistry lesson.

Hyperspectral Remote Sensing- Open Access Papers In Current Science

Current Science has a special section (open access) on Hyperspectral  Remote Sensing with papers on applications in geology, soil mapping, glacial dynamics, forestry and planetary sciences. Hyperspectral Remote Sensing involves measuring the energy from visible and infrared spectrum at very narrow intervals or channels. For example, the Hyperion sensor collects spectral information in 220 spectral bands from between the 0.4 to 2.5 µm (micrometer) bandwidth with a 30-meter ground resolution. This means scientists can use this data to identify surface objects with subtly different spectral properties. I've written about the applications of hyperspectral remote sensing in geology in an earlier post on the use of this technique in Afghanistan.

Here is a short excerpt from that post on the utility of hyperspectral imaging for mineral identification:

For the map of Afghanistan, the USGS used a sensor known as HyMap imaging spectrometer loaded aboard an aircraft. It collected spectral data covering 128 bands of 15-20 nm  (nanometer) bandwidth in the 0.4 to 2.5 µm (micrometer) range i.e the visible and the near infrared spectrum with a 5 meter ground resolution. Minerals have distinctive absorption signatures,  meaning that when sunlight strikes the surface of the earth the O-H or C-O3 or Si-O2 or Fe-OH bonds in the mineral absorb energy at a distinct wavelength, each covering a very narrow portion of the spectrum . Because conventional multispectral sensing collects energy averaged over a  broad interval it cannot discriminate between individual minerals. Hyperspectral sensing is fine grained enough (15-20 nm bandwidth) to be able to resolve the distinctive absoption signatures of several minerals.

here is the list of papers in Current Science-

Preface
Advances in spaceborne hyperspectral imaging systems
Hyperspectral image processing and analysis
Algorithms to improve spectral discrimination from Indian hyperspectral sensors data
Hyperspectral remote sensing of agriculture
Hyperspectral remote sensing: opportunities, status and challenges for rapid soil assessment in India
Monitoring of forest cover in India: imaging spectroscopy perspective
Hyperspectral remote sensing and geological applications
Snow and glacier investigations using hyperspectral data in the Himalaya
Simulating the effects of inelastic scattering on upwelling radiance in coastal and inland waters: implications for hyperspectral remote sensing
Hyperspectral remote sensing of planetary surfaces: an insight into composition of inner planets and small bodies in the solar system

 

Sunday Reading: Science Of The Himalayas- Open Access

Current Science has a special section on the science of the Himalayas with papers on a wide range of topics including papers on the seismic importance of major fault systems, interplay of faulting, climate change and sedimentary processes and a surprise!... a study of volcanic arc associated Cretaceous carbonate reefs.. built not by corals but by those enigmatic weird bivalves.. Rudists... enjoyed reading that!

• Seismotectonic implications of strike–slip earthquakes in the Darjiling–Sikkim Himalaya
  Malay Mukul, Sridevi Jade, Kutubuddin and Abdul Matin
• Climate footprints in the Late Quaternary–Holocene landforms of Dun Valley, NW Himalaya, India
  Anand K. Pandey, Prabha Pandey, Guru Dayal Singh and Navin Juyal
• Palaeogeographic significance of ‘Yasin-type’ rudist and orbitolinid fauna of the Shyok Suture Zone, Saltoro Hills, northern Ladakh, India
  Rajeev Upadhyay
• Active tectonics in the northwestern outer Himalaya: evidence of large-magnitude palaeoearthquakes in Pinjaur Dun and the Frontal Himalaya
  G. Philip, N. Suresh and S. S. Bhakuni
• Active fault study along foothill zone of Kumaun Sub-Himalya: influence on landscape shaping and drainage evolution
  Javed N. Malik, Afroz A. Shah, Sambit P. Naik, Santi S. Sahoo, Koji Okumura and Nihar R. Patra1
• Intricacies of the Himalayan seismotectonics and seismogenesis: need for integrated research
  O. P. Mishra
• When did India–Asia collide and make the Himalaya?
  A. K. Jain
• Observed changes in Himalayan glaciers
  Anil V. Kulkarni and Yogesh Karyakarte
• Seismotectonics of the great and large earthquakes in Himalaya
  J. R. Kayal

Paranoia Over Google Mapping Tools Persists In Indian Officialdom

sigh... I keep writing about this only partly as comedy.. but mostly in frustration...

From an article in the Hindu about the recently held "mapathon"contest organized by Google.

As Delhi Police investigates whether Google violated rules in holding a competition that asked users to add information about their local areas for its online map, the U.S. Internet giant on Saturday said it had responded to queries raised by Survey of India more than 10 days back and hasn’t heard from it yet. (emphasis mine)

Apparently, the Survey of India and the Defence establishment is worried that such initiatives will have grave security repercussions.  The problem is that Google has been asking users to add information about their local areas for its online map for several years now. I just don't comprehend how a mapping contest wherein lots of enthusiasts add places of interest on a map within a short span of time becomes a greater security threat than an individual using Google Maps on any other day of the year.

more from this article in the Economic Times... But on behalf of the Surveyor General of India Swarna Subba Rao, his deputy major general R C Padhi told the three ministries that Mapathon was "not in accordance with the national Mapping Policy 2005 and map restriction policies issued by the defence ministry from time to time", sources said.

Added a senior defence officer, "Such activities can have serious security repercussions in case mapping of restricted areas is undertaken by members of the general public."

The words "general public" come out of the mouths of our officials with such contempt and suspicion. These archaic mapping policies which restrict the "general public" from mapping certain areas have long been rendered meaningless by the many roving eyes that hover above the earth. I am sure the government understands this.. but relinquishing control over anything has always been hard for Indian officialdom.

The exceedingly vast majority of people using Google applications to map India don't want to harm India.

Those who do... might I remind the Indian Government that the terrorists who attacked Mumbai on November 26 2008 did not wait for a mapping contest to survey the city.

ISRO Plans New High Resolution Remote Sensing Satellite

...but will the public have easy access to the data?

Something this article does not address. India's remote sensing program is no doubt a great science and technology success and the imagery and digital data is being used by scientists for research and natural resource management.

Where India and ISRO are falling short is the continued denial of the best quality images to the public at large.  Bhuvan - ISRO's  answer to Google Maps - launched a few years ago is still serving images of India which are frustratingly inadequate for users who have by now become accustomed to razor sharp quality images of their cities and countryside from Google Maps and Google Earth.

The remote sensing satellite Cartosat-2 series has been imaging India using a panchromatic sensor at a 0.8 meter resolution since 2007.  In July 2011 India announced a new Remote Sensing data policy which allowed distribution of 1 meter resolution imagery without additional security checks. The previous policy did not allow unrestricted access to imagery finer than 5.8 meters. The policy change should ideally have resulted in image streaming applications like Bhuvan to present much sharper images of India. Almost two years since we are still getting a grainy view of India from Bhuvan.  Is the new policy not extendable to open access image streaming applications? If so, why not? Pointing to reasons of national security does not make sense since fine resolution imagery is already available through applications like Google Maps to users in India.

The image below of a portion of Pune city is the best resolution available via Bhuvan and it means that tens of millions of potential users will stay away and use Google instead.

Note To Indian Govt: It Is Pointless Banning Seismologist Roger Bilham

I wrote in my last post on the travel ban issued by the Indian Government to American seismologist Dr. Roger Bilham. The reason given was that he was engaging in activities inconsistent with his visitor visa status. These activities include attending scientific meetings and contributing towards understanding seismic risk at a proposed nuclear power plant at Jaitapur in southern Maharashtra. I do suspect that this is the real reason for the ban, which is that Dr. Bilham has irritated people in the Indian Government in charge of nuclear power plant safety by suggesting that the government's assessment of Jaitapur underestimates the risk of a large (6-7 mag.) earthquake.

Now he has answered his travel ban in the best way possible; by producing more science about the geology of the area around Jaitapur with implications for regional and site seismicity. He and his colleague Vinod Gaur have published this work in Current Science. It is open access and there is nothing the Indian Government can do to prevent his work from being widely discussed and disseminated (as I am doing now) and critically evaluated.

That by the way is what these scientists want as they outline several tests for their hypothesis and the hypothesis proposed by other geologists critical of Gaur and Bilham's earlier paper on this subject.

Making Paleoanthropology A Real Science

There is a strengthening movement towards introducing more transparency in science by making data and papers produced from publicly funded research more readily available to all those interested. Paleoanthropology which includes the study of ancient human fossils has been an especially secretive field with researchers zealously guarding their fossils until they have completed their studies and published their results.

Kate Wong in Scientific American blog writes about recent efforts to end this culture of secrecy:

...Kivell thinks concerns about sharing fossil data are misplaced. “You don’t have to worry about getting scooped,” she says, explaining that a lot of the science of interpreting fossils lies in comparing them with other fossils, which is time-consuming work. “Good science in paleoanthropology is highly comparative, highly descriptive and cannot be done fast,” Hawks agrees. “If it’s not done with extensive comparison and careful description, it’s not going to be good.”

Hawks observes that genetics had the same problem paleoanthropology has with making data accessible. But eventually the geneticists “got over it as a culture.” Indeed, it has become standard practice among geneticists to upload new sequence data to a public database before submitting a paper on the findings to a journal for publication. “I really think most people want to see things more open than they are,” Hawks says. “[Paleoanthropology] should be a real science just like genetics is a real science.”

U.S. Shale Basins Map On GeoCommons

GeoCommons, the public mapping site run by FortiusOne Inc. has added a map of shale basins of the United States to its database. Go here for the metadata and to create your own map. You can also download this data either as a kml file or a shape file or as a text file.

Since I last visited the site, Geocommons has brought more analytical capabilities into the public domain. Users can now select from a list of spatial analytical tasks like data merging, data aggregation, buffer, intersection, clip. A lot of the familiar GIS spatial functions are now available from the cloud.

You can search for geology and other data sets and can also subscribe to the feed to keep track of new additions. This is really a great open access mapping tool with a very attractive interface and plenty of options to thematically display your map attributes. You can also contribute data. Uploads can be in kml, shape or text format. You can also import data available through a web URL i.e. you can import say a kml file from another server or data that can be shared through a WMS (Web Map Service) which is a protocol for streaming map images over the internet. This way you are linking to data that is stored somewhere else. Your display will automatically update when the primary data changes.

Its really worth your time browsing through this site exploring their data collection and experimenting with making maps.

Bhuvan Continues To Be A Mixed Bag As A Citizen Mapping Tool

After my last post on the use of Google Earth to identify illegal mining in Goa, I was curious to find out if I could replicate the same in Bhuvan, India's public mapping portal.

I was disappointed:

1)  There is no historical imagery available, or at least none that I could find.  So I could not pull out older imagery to verify claims made about the presence /absence of mining before a certain date.  This is not due to a lack of older imagery. The Indian Space Research Organization has had a remote sensing satellite program since the late 1980's and imagery  of at least 23 m resolution is available for  the last couple of decades and imagery of 5.8 meter resolution is available for the last 12 years or so (IRS - 1D). The 5.8 m resolution images are fine grained enough to identify large features like open pit mines.

2) I could not find the open pit mines using "search by name". In Google Earth I could zoom onto the area of the open pit mines by searching for the nearest settlement "Maina" which was mentioned in the article on the Goa mining scam by the newspaper Herald.   In Bhuvan, the search by name database works best for towns and cities. The village level data is still incomplete. Even when a small village is present in the database the imagery does not always zoom to that area, nor is the village annotated to allow easy navigation to it. These are the basics of interactive map navigation design and Bhuvan is falling short.

On a general note, its been close to three months since the government announced that 1 meter resolution data will now be available without need for security clearances. Yet Bhuvan still is not streaming imagery finer than 5.8 meter resolution.

On the data download front, elevation data of CartoDEM 1 arc second (Digital Elevation Model derived from Cartosat 1 imagery- 1 arc second corresponds to roughly 30 meters) and Resourcesat-1: AWiFS imagery (56m) of the Indian region can be downloaded from the NRSC Open EO Data Archive. You can choose the product and the area of interest from the Bhuvan interface. The DEM download is a welcome addition. You could previously download 1 km resolution DEM of India from the USGS and also 30 m relative DEM generated from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) from NASA.

However, regarding imagery the government's all too cautious approach is perplexing. If 5.8 meter resolution and 1 meter resolution data are available and now cleared for access to all users without further security checks, why not let users download that data too?

Catching Illegal Mining In Goa Using Google Earth

Ogle Earth points to the use of open access tools like Google Earth to alert us to the possibility of illegal mining. From their blog:

There is a juicy scandal unfolding in India’s smallest and richest state, Goa, where the State Assembly’s Public Accounts Committee (PAC) has prepared a report indicting ruling Congress Party politicians for benefiting from illegal mining in the state. Illegal mining is estimated (by the Hindustan Times) to have cost Goa over USD 600 million over the past five years in lost tax revenues, turning this into a whopper of a story.....

...India’s national Directorate of Mines and Geology has now also taken an interest in the mine, ordering it to immediately cease production until it is investigated. An article by Goa’s Herald spells it out for us:

Tarcar has cheated the government by avoiding huge amounts of export duty by under-invoicing of his exports.

When presented with evidence of massive ore dumps that could not have been produced within quota, his mining company contended that these were from earlier activities. Google Earth’s imagery from 2003 effectively catches the company in a lie.

Check out the imagery here. No open pit mines in 2003. The 2011 imagery shows large open pit mines.

These ores are part of the rich iron ore belt of Goa. They are Precambrian Banded Iron Formations generally thought to be of sedimentary origin and are associated with medium and high grade meta-sedimentary rocks of the Archean schist terrain that makes up large portions of south India.

Online Interactive Geological Map Of India

I keep tabs on the India Biodiversity Portal, one of the best India based open access web mapping applications focusing on natural resources.

They have online now an interactive geological layer created by digitizing likely 1 : 1 million scale Geological Survey Of India geology maps. The contributor is R. Ravindranath of the Foundation of Ecological Security. You can click on geological units and get a description of the unit. You can also thematically style the geology based on Geological Age and Lithology. And you can control transparency so as to get an idea of the relationship between say physiography and geology. The physiography layer is one of the Google base layers available for display.

Other geology related overlay layers are India Aquifers, India Soils, India Geomorphology and India River Basins. I wish they had different display styles like transparent cross hatch, dots, symbols and lines and so on to choose from to enable easy visualization of multiple themes but perhaps that is something for the future. Unfortunately none of these geology layers are available as downloads. Government owned vector data is still not being distributed freely in digital format. I hope there is a change in policy on that soon.

But this is an important and growing resource for geology and biodiversity data. You can register and contribute layers to the natural resources database. Most Layers not under government control are downloadable (as shape files, GML and text) but contributors are free to choose the level of restrictions they want under a Creative Commons license.

Data Problems In The Indian Geospatial Industry

Geospatial World has several articles (1, 2, 3 ) on the current state of the Indian Geospatial Industry. As I have been writing on this blog, there have been several initiatives taken by the Indian government to encourage growth of this industry. Of primary concern to users is the unavailability or slow availability of useful data.

Aditi Bahn Assistant Editor, Geospatial Media and Communications Pvt. Ltd. writes:

There is no single window where all the information can be obtained. For example, if a user requires information about topography and demography of a place, he has to approach Survey of India and Census of India respectively. The two have their own procedures in place and would provide data in their own time frame. She quotes industry specialists : 

“The overhanging issue is the availability of data under one umbrella. Information is scattered and varied and have to be collated very frequently. It has become extremely challenging,” explains Aiyer.

..and (Mr. Agarwalla) -  “Even before we talk about public-private partnership, we need to talk about public-public partnership. For most of my users, just the map or census data by itself is not good enough. So can Survey of India and Census of India partner together?”

That is not unusual. Having data in two or several different places need not by itself be a big problem. Even in countries  where spatial data is relatively freely available like the U.S, many state agencies and federal agencies have ownership of their data. Finding it though is easier by going to a central data listing like the one maintained by the U.S. National Spatial Data Infrastructure. Most government agencies who produce spatial data are registered with their NSDI and follow agreed upon data standards and data dissemination practices.

In fact it is inevitable that various central and state agencies responsible for the data will want to keep ownership of it. The Indian National Spatial Data Infrastructure (NSDI) was meant to deal with exactly this problem by issuing guidelines and standards for data creation, data storage formats and data access thereby enabling users to find and combine data from different agencies with ease. The important challenge is not whether different agencies can partner each other, but getting agencies to follow standard practices in a time bound manner. The NSDI portal would then list agency addresses to go to for your data needs.

I remember talking to a senior geologist with the Geological Survey of India in 2004. I was told that digitization of 1:1 million scale geological maps is almost done and work is going on the 1:250K and selected 1:50k series. Most of this data would be ready to go online by 2006. Five years since this self-proclaimed deadline, there is still no easy way to access geology digital data.

Why has the NSDI not been successful in getting organizations to cooperate in a timely manner?

Indian Remote Sensing Data Policy Has Been Updated

A country that has launched ten remote sensing satellites has finally decided to share some of its riches with the true custodians of that data - its citizens.

The Government of India recently announced its new data policy for the management and dissemination of satellite remote sensing data. Of most interest to users is that data upto 1 meter resolution will be disseminated to all users on a "non-discriminatory basis". Previously only government users had easier access to 1 meter resolution images. Only data upto 5.8 meter resolution was being distributed to private users without permissions and security clearances.  With this new policy, the 1 meter data is still going to be pre-screened by the government to mask sensitive areas, but no further permissions will be required.

This policy although an improvement is still restrictive. If you are a private user or a private company and want data better than one meter taken from foreign or Indian satellites you will need to be approved by the government if you want to buy this best data in India. Several foreign satellites and the Indian Cartosat -2A and 2B collect sub-meter images. Data purchase in India is from the National Remote Sensing Centre.

You can of course purchase data of India taken from foreign satellites outside India also, which was one of the arguments that restrictions of any kind just don't make any sense.

What does this mean for different users of satellite data?

1) If you are a professional user of satellite images and are working with the Indian government then not much. You always had easy access to high resolution data.

2) If you are a private user or a private company then you will find ordering 1 meter resolution images easier. No further screening of your application will be necessary and you should be able to get hold of the data quicker than before.

3) For the casual user- Will Bhuvan - ISRO's flagship web mapping application - start streaming 1 meter resolution images of India?  Until now because of policy restrictions it could stream only 5.8 meter resolution images at best. This affects the non-professional user, people who are currently going to Google Maps or Google Earth for browsing images of India. If Bhuvan starts streaming 1 meter resolution images will more people move from Google to Bhuvan?

I doubt it. Google is streaming superb high resolution images of India and it may even release - or already has - sub- meter images which Bhuvan will be unable to do due to restrictions on dissemination of data better than one meter. Besides there is the problem of usability and performance. I am not very impressed with Bhuvan. The image loading is slow. The one advantage that Bhuvan had claimed over Google was India specific additional layers on natural resources. Yet I found that rendering of these layers is non-optimal and geo-processing tasks are not compatible with all browsers. In short, Bhuvan still has the look of an unfinished product. As far as popular usage of satellite images goes, Google has a substantial hold on Indian users and it looks like it will stay that way.

Mapping India: Another National GIS Effort Launched

From a trickle to a flood; the number of government backed initiatives to develop map based applications intended to reach and involve citizens to help manage India's natural and urban resources have increased over the last decade.

The latest as reported by the Economic Times is the National GIS, what appears to be a massive effort to standardize available spatial data and build resource management applications, served out over the web to different users.

I don't have enough details to comment on the particulars, but some thoughts -

The effort is touted as something of a brand new venture, although I suspect that existing applications and ongoing efforts will be grafted onto this new entity. For example, Bhoosampada (new link) allows users to browse and search for landuse and landcover data. And the National Urban GIS Mapping Mission which has promised to build standardized urban data sets is supposed to be underway to map urban areas and develop applications to aid urban governance.

My hope is that the new National GIS is not a massive duplication of efforts and that these older intiatives with some improvements will be brought within a wider umbrella effort.

There is going to a citizen layer in this application which will allow citizens to geo-tag their complaints. The principle is admirable but better governance is more hostage to a mindset than it is to technology. Today, I can either email or call or put up a status on the Pune Municipal Corporation or Pune Traffic Facebook page about a particular grievience, but the response rate is abysmal. Unless a method of personal accountability is tied up with the complaint workflow, I don't see how the citizen layer will lead to a better government -citizen partnership.

Still, it is something of a wonder that more and more government data locked up previously is making its way into the public domain. ...slowly..but that counts for progress nevertheless.