A5004228300- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Groundwater and Isotope Geochemistry
- Paleontology and Stratigraphy of Fossils
- Geological and Geochemical Analysis
- Atmospheric and Environmental Gas Dynamics
- Marine and environmental studies
- Climate variability and models
- Hydrocarbon exploration and reservoir analysis
- Marine and fisheries research
- Marine Bivalve and Aquaculture Studies
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Hydrology and Watershed Management Studies
- Tropical and Extratropical Cyclones Research
- Marine and coastal ecosystems
- Flood Risk Assessment and Management
- Pleistocene-Era Hominins and Archaeology
- Geological formations and processes
- Geochemistry and Geologic Mapping
- Geochemistry and Elemental Analysis
- Plant Water Relations and Carbon Dynamics
- earthquake and tectonic studies
- Evolution and Paleontology Studies
- Atmospheric Ozone and Climate
Indian Institute of Science Bangalore
2016-2025
Indian Academy of Sciences
2021
Iceland GeoSurvey
2020
University of Rochester
2006-2008
Florida Museum of Natural History
2008
California Institute of Technology
2005-2008
Michigan State University
2008
University of Florida
2008
Max Planck Society
2003-2006
Max Planck Institute for Biogeochemistry
2003-2006
The surface uplift of mountain belts is generally assumed to reflect progressive shortening and crustal thickening, leading their gradual rise. Recent studies the Andes indicate that elevation remained relatively stable for long periods (tens millions years), separated by rapid (1 4 million years) changes 1.5 kilometers or more. Periodic punctuated probably reflects removal unstable, dense lower lithosphere after long-term thickening crust lithospheric mantle.
The elevation of Earth's surface is among the most difficult environmental variables to reconstruct from geological record. Here we describe an approach paleoaltimetry based on independent and simultaneous determinations soil temperatures oxygen isotope compositions waters, constrained by measurements abundances 13C-18O bonds in carbonates. We use this show that Altiplano plateau Bolivian Andes rose at average rate 1.03 +/- 0.12 millimeters per year between approximately 10.3 6.7 million...
Abstract Isotopic ratios of rainwaters are believed to decrease with the amount rainfall. However, analyses isotopic composition rainwater and water vapor samples collected from Bangalore during monsoon period 2013 fail show any simple relationship local meteorological parameters whereas good correlation regional integrated convective activity. The is particularly high when averaging done over preceding 8 15 days, showing influence mixing or residence time scale atmospheric moisture. This...
Triple oxygen isotope compositions of sedimentary sulfate (∆'17O) have been applied as a tracer past primary productivity, pO2 and pCO2. However, large intraformational variability ∆'17O signatures debate surrounding how they are produced eventually preserved has limited the understanding this important geochemical record. Here we explore depositional controls on mid-Proterozoic (≈2.0-1.0 Ga) sulfates. We identify clear control magnitude signatures, with Proterozoic terrestrial environments...
The Plio-Pleistocene transition (1.5–3 million years ago) was marked by a significant drop in the atmospheric CO2 level approximately 140 ppm, driving global cooling and amplifying glacial-interglacial cycles [1,2]. While glaciation-induced continental erosion terrestrially derived organic carbon (OC) burial are typical factors considered key drivers, these processes do not fully explain causal mechanism drawdown without including regions near mid- low-latitudes [3]. ecosystem...
Abstract In order to generate a reliable and long‐lasting stable isotope ratio standard for CO 2 in samples of clean air, is liberated from well‐characterized carbonate material mixed with ‐free air. For this purpose dedicated cid r eaction ir mi xing s ystem (ARAMIS) was designed. the system, generated by conventional acid digestion powdered carbonate. Evolved gas equilibrated prefabricated comprised N , O Ar, at close ambient air concentrations. Distribution into glass flasks made stepwise...
Stable Hydrogen and Oxygen isotopic composition of water vapor, rainwater surface seawater show a distinct trend across the latitude over Southern Indian Ocean. Our observations on seawater, vapor transect covering tropical Ocean to regions showed strong latitudinal dependency; characterized by zonal process evaporation precipitation. The sampling points were spread diverse zones SST, wind speed rainfall regimes. observed physical parameters such as sea temperature, relative humidity oceanic...
Abstract High-resolution paleoclimate data on stable isotopes in a stalagmite were coupled to glycerol dialkyl tetraethers (GDGTs). The Indian Summer Monsoon (ISM) transitioned from limited rainfall during the Last Glacial Maximum (LGM) intense precipitation early Holocene (22 6 ka). This was associated with changes growth, abundance of branched (br) and isoprenoid (iso) GDGTs, as well δ 18 O, 13 C, Sr/Ca GDGT-derived signals providing both temperature moisture information. reconstructed...
Triple oxygen isotope systematics has evolved as a powerful tool in understanding various earth system processes. It proven reliable assessing paleoenvironmental conditions from natural archives (e.g., waters, ice cores, biota, sediments, etc.) owing to recent advances high-precision mass spectrometric analysis. Toward the standardization of triple analyses carbonates, we describe procedure Δ′17O analysis carbonates by two-step protocol: acid digestion evolve CO2 followed catalytic CO2–O2...
Abstract The Amba Dongar carbonatite‐alkaline complex is regarded as a late phase intrusion ( ca . 65 Ma) associated with Deccan volcanism. Existing age constraints on the carbonatite are based phlogopite 40 Ar– 39 Ar plateau ages derived from and alkaline rocks within complex. We explore utility of apatite, common accessory mineral in carbonatites, petrogenetic geochronological tool to constrain further evolution carbonatites. Apatite exhibits different crystal forms—from hexagonal stubby...
Abstract Variations in the isotope ratios ( 18 O/ 16 O and D/H) of meteoric water at continental stations serve as valuable tracers for hydrological cycle. In present study, we investigated role sea surface temperature, wind speed, relative humidity, rainout processes on stable isotopic composition 2010 monsoon rainwater Bangalore. The over ocean influences temperature humidity which turn influence vapor composition. Arabian Sea land mass (Western Ghats) during advection air parcel to...
Abstract The moisture transport and precipitation in the western Himalayas is an interplay of two atmospheric systems: Western Disturbances (WDs) Indian Summer Monsoon (ISM). WDs primarily from Mediterranean Sea Atlantic Ocean, while ISM transports Arabian Bay Bengal. Local sources also contribute to regional budget. can be distinguished by measuring dual isotopic signatures precipitation. Oxygen hydrogen ratios measured daily samples collected at Srinagar, Kashmir March 2015–April 2017,...