Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Agricultural Pollution (1)
- Anisotropy (1)
- Aquifers (1)
- Byproducts (1)
- Carbon (1)
-
- Carbon Dioxide (1)
- Carbon Isotope Ratio (1)
- Carbon Substrates (1)
- Concentration Measurement (1)
- Denitrification (1)
- Dissolution (1)
- Dissolved Inorganic Carbon (1)
- Dissolved Oxygen (1)
- Groundwater (1)
- Groundwater Quality (1)
- Groundwater Resources (1)
- Isotope Ratio (1)
- Isotopes (1)
- Isotopic Composition (1)
- Low Dissolved Oxygen (1)
- Michigan (1)
- Nitrate (1)
- Nitrate Levels (1)
- Nitrogen (1)
- Organic Carbon (1)
- PH (1)
- Polarization (1)
- Rift (1)
- Shear wave splitting (1)
- Soil Organic Matters (1)
Articles 1 - 3 of 3
Full-Text Articles in Earth Sciences
S K S Splitting Beneath Continental Rift Zones, Stephen S. Gao, Paul M. Davis, Kelly H. Liu, Philip D. Slack, Andrew W. Rigor, Yu A. Zorin, Valentina V. Mordvinova, Vladimir M. Kozhevnikov, Nikolai A. Logatchev
S K S Splitting Beneath Continental Rift Zones, Stephen S. Gao, Paul M. Davis, Kelly H. Liu, Philip D. Slack, Andrew W. Rigor, Yu A. Zorin, Valentina V. Mordvinova, Vladimir M. Kozhevnikov, Nikolai A. Logatchev
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
We present measurements of S K S splitting at 28 digital seismic stations and 35 analog stations in the Baikal rift zone, Siberia, and adjacent areas, and at 17 stations in the East African Rift in Kenya and compare them with previous measurements from the Rio Grande Rift of North America. Fast directions in the inner region of the Baikal rift zone are distributed in two orthogonal directions, NE and NW, approximately parallel and perpendicular to the NE strike of the rift. In the adjacent Siberian platform and northern Mongolian fold belt, only the rift-orthogonal fast direction is observed. In …
A Bayesian Nonlinear Inversion Of Seismic Body-Wave Attenuation Factors, Stephen S. Gao
A Bayesian Nonlinear Inversion Of Seismic Body-Wave Attenuation Factors, Stephen S. Gao
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
It is a well-known fact that the uncertainties in measuring relative attenuation factors within a local or regional seismic network are usually high, due to noise of different kinds and unrealistic assumptions. Numerical experiments using nine synthetic seismograms, created using t* values ranging from 0.1 to 0.9 sec, reveal that the commonly used spectral ratio method is strongly affected by the selection of data processing parameters such as width of the spectral smoothing window, reference station, and so on. The numerical experiments demonstrate that a Bayesian nonlinear inversion approach that directly matches the spectra is better at finding the correct …
Concentrations And Isotope Ratios Of Dissolved Inorganic Carbon In Denitrifying Environments, C. Nascimento, Eliot A. Atekwana, R. V. Krishnamurthy
Concentrations And Isotope Ratios Of Dissolved Inorganic Carbon In Denitrifying Environments, C. Nascimento, Eliot A. Atekwana, R. V. Krishnamurthy
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
We measured the concentration and isotope ratio of dissolved inorganic carbon (DIC) in groundwater associated with denitrification (Corg + NO3- = CO2 + N2) in an agriculturally impacted site in southwestern Michigan. Samples with the lowest nitrate levels also had low dissolved oxygen content and were more depleted in δ13C than background groundwater. All the samples had DIC concentrations in excess of titratable alkalinity. The magnitude of this DIC in excess of alkalinity correlated with a decreasing δ13C attesting to the presence of CO2 derived from organic carbon. Carbon …