Anna Kelbert, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 27
Geomagnetism Program research plan, 2020–2024
The Geomagnetism Program of the U.S. Geological Survey (USGS) monitors geomagnetic field variation through operation of a network of observatories across the United States and its territories, and it pursues scientific research needed to estimate and assess geomagnetic and geoelectric hazards. Over the next five years (2020–2024 inclusive) and in support of national and agency priorities, Geomagne
Authors
Jeffrey J. Love, Anna Kelbert, Benjamin S. Murphy, E. Joshua Rigler, Kristen A. Lewis
Modified GIC estimation using 3-D Earth conductivity
Geomagnetically induced currents (GICs) are quasi-direct current (DC) electric currents that flow in technological conductors during geomagnetic storms. Extreme GICs are hazardous to man-made infrastructure. GICs enter and exit the technological systems, such as the electric power grid, at grounding points, and their magnitudes depend on the currents that flow underground. They are, therefore, a f
Authors
Anna Kelbert, Greg M. Lucas
A 100-year geoelectric hazard analysis for the U.S. high-voltage power grid
A once-per-century geoelectric hazard map is created for the United States high-voltage
power grid. A statistical extrapolation from 31 years of magnetic field measurements is
made by identifying 84 geomagnetic storms with the Kp and Dst indices. Data from 24
geomagnetic observatories, 1079 magnetotelluric survey sites, and 17,258 transmission
lines are utilized to perform a geoelectric hazard
Authors
Greg M. Lucas, Jeffrey J. Love, Anna Kelbert, Paul A. Bedrosian, E. Joshua Rigler
Empirical estimation of natural geoelectric hazards
Geoelectric field time series can be estimated by convolving estimates of Earth‐surface impedance, such as those obtained from magnetotelluric survey measurements, with historical records of geomagnetic variation obtained at magnetic observatories. This straightforward procedure permits the mapping of geoelectric field variation during magnetic storms. Statistical analysis of the time series allow
Authors
Jeffrey J. Love, Paul A. Bedrosian, Anna Kelbert, Greg M. Lucas
The first 3D conductivity model of the contiguous US: Reflections on geologic structure and application to induction hazards
Estimation of ground level geoelectric fields has been identified by the National Space Weather Action Plan as a key component of assessment and mitigation of space weather impacts on critical infrastructure. Estimates of spatially and temporally variable electric fields are used to generate statistically based hazard maps and show promise toward monitoring and responding to geomagnetic disturbanc
Authors
Anna Kelbert, Paul A. Bedrosian, Benjamin S. Murphy
Data sharing in magnetotellurics
Here, we introduce the first openly available comprehensive database of magnetotelluric (MT) and related electromagnetic data that we developed and matured over the past decade, explain how to access the data, and describe the challenges that had to be overcome to make MT data sharing possible. The database is a helpful tool for MT scientists, and is widely used by the international scientific com
Authors
Anna Kelbert, Svetlana Erofeeva, Chad Trabant, Rich Karstens, Mickey C. Van Fossen
Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey, with decades‐long, 1‐min resolution time series of g
Authors
Jeffrey J. Love, Greg M. Lucas, Paul A. Bedrosian, Anna Kelbert
Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with historical 1‐min (2‐min Nyquist) geomagnetic variation time
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
On the feasibility of real-time mapping of the geoelectric field across North America
A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real-time mapping of geoelectric fields is a challenge
Authors
Jeffrey J. Love, E. Joshua Rigler, Anna Kelbert, Carol A. Finn, Paul A. Bedrosian, Christopher C. Balch
Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances
Commonly, one-dimensional (1-D) Earth impedances have been used to calculate the voltages induced across electric power transmission lines during geomagnetic storms under the assumption that much of the three-dimensional structure of the Earth gets smoothed when integrating along power transmission lines. We calculate the voltage across power transmission lines in the mid-Atlantic region with both
Authors
Greg M. Lucas, Jeffrey J. Love, Anna Kelbert
Geoelectric hazard maps for the Mid-Atlantic United States: 100 year extreme values and the 1989 magnetic storm
Maps of extreme value geoelectric field amplitude are constructed for the Mid‐Atlantic United States, a region with high population density and critically important power grid infrastructure. Geoelectric field time series for the years 1983–2014 are estimated by convolving Earth surface impedances obtained from 61 magnetotelluric survey sites across the Mid‐Atlantic with historical 1 min (2 min Ny
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
Some results from ModEM3DMT, the freely available OSU 3D MT inversion code
At the 3DEM-5 workshop in 2013, we presented a paper entitled "ModEM: developing 3D EM inversion for the masses", outlining our then recent development of a modular system for inversion of EM geophysical data, called ModEM. As promised in that presentation, we made a version of the code that is suitable for 3D modeling and inversion of magnetotelluric data freely available for academic use shortly
Authors
Gary D. Egbert, Naser Meqbel, Anna Kelbert
Science and Products
Filter Total Items: 27
Geomagnetism Program research plan, 2020–2024
The Geomagnetism Program of the U.S. Geological Survey (USGS) monitors geomagnetic field variation through operation of a network of observatories across the United States and its territories, and it pursues scientific research needed to estimate and assess geomagnetic and geoelectric hazards. Over the next five years (2020–2024 inclusive) and in support of national and agency priorities, Geomagne
Authors
Jeffrey J. Love, Anna Kelbert, Benjamin S. Murphy, E. Joshua Rigler, Kristen A. Lewis
Modified GIC estimation using 3-D Earth conductivity
Geomagnetically induced currents (GICs) are quasi-direct current (DC) electric currents that flow in technological conductors during geomagnetic storms. Extreme GICs are hazardous to man-made infrastructure. GICs enter and exit the technological systems, such as the electric power grid, at grounding points, and their magnitudes depend on the currents that flow underground. They are, therefore, a f
Authors
Anna Kelbert, Greg M. Lucas
A 100-year geoelectric hazard analysis for the U.S. high-voltage power grid
A once-per-century geoelectric hazard map is created for the United States high-voltage
power grid. A statistical extrapolation from 31 years of magnetic field measurements is
made by identifying 84 geomagnetic storms with the Kp and Dst indices. Data from 24
geomagnetic observatories, 1079 magnetotelluric survey sites, and 17,258 transmission
lines are utilized to perform a geoelectric hazard
Authors
Greg M. Lucas, Jeffrey J. Love, Anna Kelbert, Paul A. Bedrosian, E. Joshua Rigler
Empirical estimation of natural geoelectric hazards
Geoelectric field time series can be estimated by convolving estimates of Earth‐surface impedance, such as those obtained from magnetotelluric survey measurements, with historical records of geomagnetic variation obtained at magnetic observatories. This straightforward procedure permits the mapping of geoelectric field variation during magnetic storms. Statistical analysis of the time series allow
Authors
Jeffrey J. Love, Paul A. Bedrosian, Anna Kelbert, Greg M. Lucas
The first 3D conductivity model of the contiguous US: Reflections on geologic structure and application to induction hazards
Estimation of ground level geoelectric fields has been identified by the National Space Weather Action Plan as a key component of assessment and mitigation of space weather impacts on critical infrastructure. Estimates of spatially and temporally variable electric fields are used to generate statistically based hazard maps and show promise toward monitoring and responding to geomagnetic disturbanc
Authors
Anna Kelbert, Paul A. Bedrosian, Benjamin S. Murphy
Data sharing in magnetotellurics
Here, we introduce the first openly available comprehensive database of magnetotelluric (MT) and related electromagnetic data that we developed and matured over the past decade, explain how to access the data, and describe the challenges that had to be overcome to make MT data sharing possible. The database is a helpful tool for MT scientists, and is widely used by the international scientific com
Authors
Anna Kelbert, Svetlana Erofeeva, Chad Trabant, Rich Karstens, Mickey C. Van Fossen
Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey, with decades‐long, 1‐min resolution time series of g
Authors
Jeffrey J. Love, Greg M. Lucas, Paul A. Bedrosian, Anna Kelbert
Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with historical 1‐min (2‐min Nyquist) geomagnetic variation time
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
On the feasibility of real-time mapping of the geoelectric field across North America
A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real-time mapping of geoelectric fields is a challenge
Authors
Jeffrey J. Love, E. Joshua Rigler, Anna Kelbert, Carol A. Finn, Paul A. Bedrosian, Christopher C. Balch
Calculation of voltages in electric power transmission lines during historic geomagnetic storms: An investigation using realistic earth impedances
Commonly, one-dimensional (1-D) Earth impedances have been used to calculate the voltages induced across electric power transmission lines during geomagnetic storms under the assumption that much of the three-dimensional structure of the Earth gets smoothed when integrating along power transmission lines. We calculate the voltage across power transmission lines in the mid-Atlantic region with both
Authors
Greg M. Lucas, Jeffrey J. Love, Anna Kelbert
Geoelectric hazard maps for the Mid-Atlantic United States: 100 year extreme values and the 1989 magnetic storm
Maps of extreme value geoelectric field amplitude are constructed for the Mid‐Atlantic United States, a region with high population density and critically important power grid infrastructure. Geoelectric field time series for the years 1983–2014 are estimated by convolving Earth surface impedances obtained from 61 magnetotelluric survey sites across the Mid‐Atlantic with historical 1 min (2 min Ny
Authors
Jeffrey J. Love, Greg M. Lucas, Anna Kelbert, Paul A. Bedrosian
Some results from ModEM3DMT, the freely available OSU 3D MT inversion code
At the 3DEM-5 workshop in 2013, we presented a paper entitled "ModEM: developing 3D EM inversion for the masses", outlining our then recent development of a modular system for inversion of EM geophysical data, called ModEM. As promised in that presentation, we made a version of the code that is suitable for 3D modeling and inversion of magnetotelluric data freely available for academic use shortly
Authors
Gary D. Egbert, Naser Meqbel, Anna Kelbert