Geodetic contributions to the study of seismotectonics in India

Earthquakes in India are caused by the release of elastic strain energy created and replenished by the stresses resulting from India's collision with Asia. Accumulating strain distorts the surface of the Indian plate, which despite its slow development can now be detected using precision geodesy. The largest and most severe earthquakes occur on the boundaries of the Indian plate to the east, north and west of the subcontinent. Historically, these areas have been somewhat neglected by precise geodesy and it is only recently that suitably dense networks capable of spanning entire plate boundaries have been developed. Earthquakes within the subcontinent, though devastating, have also remained unserved by historical geodesy in India because the rupture areas of these events are small and have tended to occur between networks of adequate precision. Since 1990, the widespread availability of GPS geodesy has resulted in a number of significant findings related to the translation, deformation and rotation of the Indian plate, and to deformation of its margins. The next decade is likely to see the uncertainties of these estimates fall by a factor of 4, permitting estimates of changes of rate in space and time. We discuss these new findings and their historical antecedents, and identify current trends in seismogeodetic research that are likely to contribute to a new understanding of future Indian earthquakes

Geodetic constraints on the translation and deformation of India: implications for future great Himalayan earthquakes

Because the elastic deformation of rock is fundamental to the earthquake process, geodetic surface measurements provide a measure of both the geometrical parameters of earthquake rupture, and a measure of the temporal and spatial development of elastic strain prior to rupture. Yet, despite almost 200 years of geodesy in India, and the occurrence of several great earthquakes, the geodetic contribution to understanding future damaging earthquakes in India remains minor. Global Positioning System (GPS) geodesy promises to remedy the shortcomings of traditional studies. Within the last decade, GPS studies have provided three fundamental constraints concerning the seismogenic framework of the Indian Plate: its overall stability < 0.01 μstrainlyear), its velocity of collision with Asia (58 ± 4 mm/year at N44E), and its rate of collision with southern Tibet (20.5 ± 2 mm/year). These NE directed motions are superimposed on a secular shift of the Earth's rotation axis. As a net result, India currently moves southward at 8 ± 1 cm/ year. In the next few decades we can expect GPS measurements to illuminate the subsurface distribution and rate of development of strain in the Himalaya, the relative contributions of along-arc and arc-normal deformation in the Himalaya and southern Tibet, and perhaps the roles of potential energy, plastic deformation and elastic strain in the earthquake cycle

A Framework for India's Water Policy. (NIAS Report No. R4-2009)

As India plans for an expanded economic future, its expectations are jeopardized for want of a unifying national water policy. Formulating such a policy is a daunting task. In a technological world, sustained equitable water management to meet diverse needs of all segments of society demands a coming together of the best available scientific knowledge, avowed human values of democracy and social justice, and a will to adapt governance to complex interactions between ineluctable earth processes and human society. Therefore, a rational policy on water has necessarily to start with an overarching framework that recognizes the attributes of the remarkable natural phenomenon we call water, the physical limits of India’s water endowments governed by these attributes, and the imperatives of civilized adaptation of India’s citizens to the constraints imposed by immutable laws of nature that govern its dynamic. Such a framework will ideally lay down certain broad principles that will guide the crafting of laws, statutes, regulations, and conventions despite the spatial and temporal variability in water occurrence around the country. This paper presents such a unifying framework by placing India’s water endowments in the context of the hydrological cycle, and perspectives of legal and cultural traditions that facilitate a just adaptation of society to a sharing of common resource vital for the survival of all living things. Comprehending the nature of water and civilized living within these constraints requires a harmonious coming together of all branches of human knowledge from the sciences to the humanities

Whole genome resequencing and phenotyping of MAGIC population for high resolution mapping of drought tolerance in chickpea

Terminal drought is one of the major constraints to crop production in chickpea (Cicer arietinum L.). In order to map drought tolerance related traits at high resolution, we sequenced multi-parent advanced generation intercross (MAGIC) population using whole genome resequencing approach and phenotyped it under drought stress environments for two consecutive years (2013-14 and 2014-15). A total of 52.02 billion clean reads containing 4.67 TB clean data were generated on the 1136 MAGIC lines and eight parental lines. Alignment of clean data on to the reference genome enabled identification of a total, 932,172 of SNPs, 35,973 insertions, and 35,726 deletions among the parental lines. A high-density genetic map was constructed using 57,180 SNPs spanning a map distance of 1606.69 cM. Using compressed mixed linear model, genome-wide association study (GWAS) enabled us to identify 737 markers significantly associated with days to 50% flowering, days to maturity, plant height, 100 seed weight, biomass, and harvest index. In addition to the GWAS approach, an identity-by-descent (IBD)-based mixed model approach was used to map quantitative trait loci (QTLs). The IBD-based mixed model approach detected major QTLs that were comparable to those from the GWAS analysis as well as some exclusive QTLs with smaller effects. The candidate genes like FRIGIDA and CaTIFY4b can be used for enhancing drought tolerance in chickpea. The genomic resources, genetic map, marker-trait associations, and QTLs identified in the study are valuable resources for the chickpea community for developing climate resilient chickpeas

A genome-scale integrated approach aids in genetic dissection of complex flowering time trait in chickpea

A combinatorial approach of candidate gene-based association analysis and genome-wide association study (GWAS) integrated with QTL mapping, differential gene expression profiling and molecular haplotyping was deployed in the present study for quantitative dissection of complex flowering time trait in chickpea. Candidate gene-based association mapping in a flowering time association panel (92 diverse desi and kabuli accessions) was performed by employing the genotyping information of 5724 SNPs discovered from 82 known flowering chickpea gene orthologs of Arabidopsis and legumes as well as 832 gene-encoding transcripts that are differentially expressed during flower development in chickpea. GWAS using both genome-wide GBS- and candidate gene-based genotyping data of 30,129 SNPs in a structured population of 92 sequenced accessions (with 200–250 kb LD decay) detected eight maximum effect genomic SNP loci (genes) associated (34 % combined PVE) with flowering time. Six flowering time-associated major genomic loci harbouring five robust QTLs mapped on a high-resolution intra-specific genetic linkage map were validated (11.6–27.3 % PVE at 5.4–11.7 LOD) further by traditional QTL mapping. The flower-specific expression, including differential up- and down-regulation (>three folds) of eight flowering time-associated genes (including six genes validated by QTL mapping) especially in early flowering than late flowering contrasting chickpea accessions/mapping individuals during flower development was evident. The gene haplotype-based LD mapping discovered diverse novel natural allelic variants and haplotypes in eight genes with high trait association potential (41 % combined PVE) for flowering time differentiation in cultivated and wild chickpea. Taken together, eight potential known/candidate flowering time-regulating genes [efl1 (early flowering 1), FLD (Flowering locus D), GI (GIGANTEA), Myb (Myeloblastosis), SFH3 (SEC14-like 3), bZIP (basic-leucine zipper), bHLH (basic helix-loop-helix) and SBP (SQUAMOSA promoter binding protein)], including novel markers, QTLs, alleles and haplotypes delineated by aforesaid genome-wide integrated approach have potential for marker-assisted genetic improvement and unravelling the domestication pattern of flowering time in chickpea

Association of Type 1 Diabetes vs Type 2 Diabetes Diagnosed During Childhood and Adolescence With Complications During Teenage Years and Young Adulthood

The burden and determinants of complications and comorbidities in contemporary youth-onset diabetes are unknown

Exergy Analysis: A Guide to Sustainability?

This paper argues for a continuing exploration of Nature’s organizing principles that sustain prolonged homeostasis of the earth’s ecosystems punctuated by forceful transitions to new emergent states. Ecosystems develop and maintain a dynamically stable state by transacting energy and materials with the surrounding flows to keep reversing their continual fall to the ground state. Conversely, the elevation of any component of the ecosystem above the ground level may be regarded as a measure of its functional efficiency. This measure, called exergy, can be calculated for an eco-subsystem based on knowledge of the energy and material fluxes that thread it and, most importantly, of where the ground level happens to be. Admittedly, it is not straightforward to quantify these figures, and the departure of assumptions from reality will inevitably translate into errors in the calculated exergy figures. However, the variance may be estimated by analysing the results of an ensemble of calculations with randomly perturbed input values. Even with these limitations, however, a map of exergy losses characterizing different parts of an ecosystem has the potential to reveal relative thermodynamic efficiencies for appropriate ameliorative interventions

Exergy Analysis: A Guide to Sustainability?

This paper argues for a continuing exploration of Nature’s organizing principles that sustain prolonged homeostasis of the earth’s ecosystems punctuated by forceful transitions to new emergent states. Ecosystems develop and maintain a dynamically stable state by transacting energy and materials with the surrounding flows to keep reversing their continual fall to the ground state. Conversely, the elevation of any component of the ecosystem above the ground level may be regarded as a measure of its functional efficiency. This measure, called exergy, can be calculated for an eco-subsystem based on knowledge of the energy and material fluxes that thread it and, most importantly, of where the ground level happens to be. Admittedly, it is not straightforward to quantify these figures, and the departure of assumptions from reality will inevitably translate into errors in the calculated exergy figures. However, the variance may be estimated by analysing the results of an ensemble of calculations with randomly perturbed input values. Even with these limitations, however, a map of exergy losses characterizing different parts of an ecosystem has the potential to reveal relative thermodynamic efficiencies for appropriate ameliorative interventions

Shear wave velocity structure beneath the Archaean granites around Hyderabad, inferred from receiver function analysis

Broadband receiver functions abstracted from teleseismicP waveforms recorded by a 3-component Streckeisen seismograph at Hyderabad, have been inverted to constrain the shear velocity structure of the underlying crust. Receiver functions obtained from the Hyderabad records of both shallow and intermediate focus earthquakes lying in different station-event azimuths, show a remarkable coherence in arrival times and shapes of the significant shear wave phases:Ps, PpPs, PsPs/PpSs, indicating horizontal stratification within the limits of resolution. This is also supported by the relatively small observed amplitudes of the tangential component receiver functions which are less than 10% of the corresponding radial component. Results of several hundred inversions of stacked receiver functions from closely clustered events (within 2°), show that the crust beneath the Hyderabad granites has a thickness of 36 ± 1 km, consisting of a 10 km thick top layer in which shear wave velocity is 3.54 ± 0.07 km/sec, underlain by a 26 ± 1 km thick lower crust in which the shear wave velocity varies uniformly with a small gradient of 0.02 km/sec/km. The shear wave velocity at its base is 4.1 ± 0.05 km/sec, just above the moho transition zone which is constrained to be less than 4 km thick, overlying a 4.74 ±0.1 km/sec half space

Earthquakes: Himalayan seismic hazard

The devastating earthquake in Bhuj on 26 January 2001 highlighted the high earthquake risk in the Indian region of Gujarat. In their Perspective, Bilham et al. warn that major earthquakes may be expected in another part of India, the Himalayan arc. An analysis of historic earthquakes suggests that several major earthquakes are overdue in this region but that recent low activity has focused attention away from the Himalayan arc. Projections from earlier earthquakes suggest that just one of the possibly overdue Himalayan earthquakes may lead to 200,000 predictable fatalities