Anna Kelbert, Ph.D.
In 2006, I joined Oregon State University (OSU) in Corvallis, OR as a postdoctoral scholar.
While at OSU, I was a leading developer of the Modular Electromagnetic Inversion Software (ModEM), and supported a growing user base for this code. I contributed to the NSF's EarthScope USArray MT program through quality control, processing and archiving of the data in the years 2006-2015. I also contributed to multiple NSF projects focused in magnetotellurics, global electromagnetics, and development of metadata standards and cyberinfrastructure. I became an Assistant Professor (Senior Researcher) at OSU in July 2014, and joined the USGS Geomagnetism Program in Golden, CO in May 2015.
Research Interests
Geophysics
Composition of the Earth's crust and mantle as inferred from electrical conductivity of the solid Earth; magnetotelluric and other electromagnetic data interpretation and inversion at regional to global scales; water content and processes in global subduction settings; tectonics and magmatism of the North America; joint interpretation of electromagnetic, seismic and geodynamic models of the Earth's interior.
Hazards
Effects of space weather on electric power grids and pipelines; geomagnetic storms; geomagnetically induced currents (GIC); volcano imaging using electromagnetics.
Computing
Physics-based numerical modeling and high-performance computing; scientific workflows; semantics and controlled vocabularies for science; databases and frameworks for long-term sharing and storage of numerical models and data.
Active Projects
In the past 5 years, I developed a suite of data sharing tools for magnetotellurics, including a modern XML-based file format for transfer functions, open-source tools for data format conversions and the first publicly accessible, searchable database (SPUD EMTF), as well as a strategy for credit attribution with citable Data Object Identifiers (DOIs). Through these efforts, I am hoping to develop the culture of data sharing in the worldwide magnetotelluric community, and thereby enable next generation of scientific analysis. I continue to contribute, solicit external data contributions and provide support for data uploads and generation of citable DOIs for such data sets. If you have historic or recently collected magnetotelluric data in any format, and are willing and able to share your data set with the worldwide scientific community, I'd love to hear from you!
In my current role as a Research Geophysicist at the USGS Geomagnetism Program, I provide technical support to the NOAA's Space Weather Prediction Center (SWPC) Geoelectric Field Maps data product that is currently in development. I provide scientific
Education and Certifications
2006 - Ph.D. in Mathematical Geophysics, Cardiff University, UK
2002 - B.A. in Mathematics, Cambridge University, UK
Science and Products
Development of a Flexible Multi-Channel Spatiotemporal Geophysical HDF5 Data Format Supporting FAIR
Metadata standards for Magnetotelluric Time Series Data
Hybrid CPU-GPU solution to regularized divergence-free curl-curl equations for electromagnetic inversion problems
Geoelectric field model validation in the southern California Edison system: Case study
The March 1940 superstorm: Geoelectromagnetic hazards and impacts on American communication and power systems
Estimating geomagnetically induced currents in southern Brazil using 3-D Earth resistivity model
Geoelectric constraints on the Precambrian assembly and architecture of southern Laurentia
Mapping a magnetic superstorm: March 1989 geoelectric hazards and impacts on United States power systems
Characteristics and sources of intense geoelectric fields in the United States: Comparative analysis of multiple geomagnetic storms
Down to Earth with nuclear electromagnetic pulse: Realistic surface impedance affects mapping of the E3 geoelectric hazard
Magnetotelluric sampling and geoelectric hazard estimation: Are national-scale surveys sufficient?
Simultaneous observations of geoelectric and geomagnetic fields produced by magnetospheric ULF waves
Geomagnetism Program research plan, 2020–2024
Modified GIC estimation using 3-D Earth conductivity
Electromagnetic Transfer Function File Conversion Utilities (EMTF FCU)
Science and Products
- Science
Development of a Flexible Multi-Channel Spatiotemporal Geophysical HDF5 Data Format Supporting FAIR
A unique opportunity for USGS to collaborate with IRIS-PASSCAL (the national seismic instrument facility) has presented itself to develop a geophysical data archive format that follows FAIR principles. IRIS-PASSCAL is extending facility to include magnetotelluric (MT) instruments prescribing the need for them to archive collected MT data by extending their existing protocol. Concurrently, Congre - Data
Metadata standards for Magnetotelluric Time Series Data
Magnetotellurics (MT) is an electromagnetic geophysical method that is sensitive to variations in subsurface electrical resistivity. Measurements of natural electric and magnetic fields are done in the time domain, where instruments can record for a couple of hours up to mulitple months resulting in data sets on the order of gigabytes. The principles of findability, accessibility, interoperabili - Publications
Filter Total Items: 25
Hybrid CPU-GPU solution to regularized divergence-free curl-curl equations for electromagnetic inversion problems
The Curl-Curl equation is the foundation of time-harmonic electromagnetic (EM) problems in geophysics. The efficiency of its solution is key to EM simulations, accounting for over 95% of the computation cost in geophysical inversions for magnetotelluric or controlled-source EM problems. However, most published EM inversion codes are still central processing unit (CPU)-based and cannot utilize receAuthorsHao Dong, Kai Sun, Gary D. Egbert, Anna Kelbert, Naser MeqbelGeoelectric field model validation in the southern California Edison system: Case study
Geomagnetic storms are a natural phenomenon that cause magnetic field variations at the surface of the Earth. These variations induce electrical current in natural and artificial conductors at and below the surface, resulting in geomagnetically induced currents (GIC) in power systems. The key to modeling GIC is to estimate the geoelectric field in the region of the power grid. The estimation of GIAuthorsChristopher C. Balch, Chaoyang Jing, Anna Kelbert, Patricia Arons, Kevin RichardsonThe March 1940 superstorm: Geoelectromagnetic hazards and impacts on American communication and power systems
An analysis is made of geophysical records of the 24 March 1940, magnetic storm and related reports of interference on long-line communication and power systems across the contiguous United States and, to a lesser extent, Canada. Most long-line system interference occurred during local daytime, after the second of two storm sudden commencements and during the early part of the storm's main phase.AuthorsJeffrey J. Love, E. Joshua Rigler, Michael D Hartinger, Greg M. Lucas, Anna Kelbert, Paul A. BedrosianEstimating geomagnetically induced currents in southern Brazil using 3-D Earth resistivity model
Geomagnetically induced currents (GICs) result from the interaction of the time variation of ground magnetic field during a geomagnetic disturbance with the Earth's deep electrical resistivity structure. In this study, we simulate induced GICs in a hypothetical representation of a low-latitude power transmission network located mainly over the large Paleozoic Paraná basin (PB) in southern Brazil.AuthorsKaren V. Espinosa Sarmiento, Antonio L. Padilha, Livia R. Alves, Adam Schultz, Anna KelbertGeoelectric constraints on the Precambrian assembly and architecture of southern Laurentia
Using images from an updated and expanded three-dimensional electrical conductivity synthesis model for the contiguous United States (CONUS), we highlight the key continent-scale geoelectric structures that are associated with the Precambrian assembly of southern Laurentia. Conductivity anomalies are associated with the Trans-Hudson orogen, the Penokean suture, the ca. 1.8–1.7 Ga Cheyenne belt andAuthorsBenjamin Scott Murphy, Paul A. Bedrosian, Anna KelbertMapping a magnetic superstorm: March 1989 geoelectric hazards and impacts on United States power systems
A study is made of the relationships between geomagnetic and geoelectric field variation, Earth-surface impedance, and operational interference (anomalies) experienced on electric-power systems across the contiguous United States during the March 13-14, 1989 magnetic storm. For this, a 1-minute-resolution sequence of geomagnetic field maps is constructed from magnetometer time series acquired at gAuthorsJeffrey J. Love, Greg M. Lucas, E. Joshua Rigler, Benjamin Scott Murphy, Anna Kelbert, Paul A. BedrosianCharacteristics and sources of intense geoelectric fields in the United States: Comparative analysis of multiple geomagnetic storms
Intense geoelectric fields during geomagnetic storms drive geomagnetically induced currents in power grids and other infrastructure, yet there are limited direct measurements of these storm-time geoelectric fields. Moreover, most previous studies examining storm-time geoelectric fields focused on single events or small geographic regions, making it difficult to determine the typical source(s) of iAuthorsXueling Shi, Michael D Hartinger, Joseph B. H. Baker, Benjamin Scott Murphy, Paul A. Bedrosian, Anna Kelbert, Erin (Josh) RiglerDown to Earth with nuclear electromagnetic pulse: Realistic surface impedance affects mapping of the E3 geoelectric hazard
An analysis is made of Earth-surface geoelectric fields and voltages on electricity transmission power-grids induced by a late-phase E3 nuclear electromagnetic pulse (EMP). A hypothetical scenario is considered of an explosion of several hundred kilotons set several hundred kilometers above the eastern-midcontinental United States. Ground-level E3 geoelectric fields are estimated by convolving a sAuthorsJeffrey J. Love, Greg M. Lucas, Benjamin Scott Murphy, Paul A. Bedrosian, E. Joshua Rigler, Anna KelbertMagnetotelluric sampling and geoelectric hazard estimation: Are national-scale surveys sufficient?
At present, the most reliable information for inferring storm-time ground electric fields along electrical transmission lines comes from coarsely sampled, national-scale magnetotelluric (MT) data sets, such as that provided by the EarthScope USArray program. An underlying assumption in the use of such data is that they adequately sample the spatial heterogeneity of the surface relationship betweenAuthorsBenjamin Scott Murphy, Greg M. Lucas, Jeffrey J. Love, Anna Kelbert, Paul A. Bedrosian, E. Joshua RiglerSimultaneous observations of geoelectric and geomagnetic fields produced by magnetospheric ULF waves
Geomagnetic perturbations (BGEO) related to magnetospheric ultralow frequency (ULF) waves induce electric fields within the conductive Earth—geoelectric fields (EGEO)—that in turn drive geomagnetically induced currents. Though numerous past studies have examined ULF wave BGEO from a space weather perspective, few studies have linked ULF waves with EGEO. Using recently available magnetotelluric impAuthorsM. D. Hartinger, X. R. Shih, G. Lucas, Benjamin Scott Murphy, Anna Kelbert, J.B.H. Baker, E. Joshua Rigler, Paul A. BedrosianGeomagnetism 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, GeomagneAuthorsJeffrey J. Love, Anna Kelbert, Benjamin S. Murphy, E. Joshua Rigler, Kristen A. LewisModified 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 fAuthorsAnna Kelbert, Greg M. Lucas - Software
Electromagnetic Transfer Function File Conversion Utilities (EMTF FCU)
Magnetotelluric impedances and other similar transfer functions are important for geophysical interpretation and for space weather hazards. I helped develop and continue to curate a database known as IRIS EMTF, http://ds.iris.edu/spud/emtf which uses something called EMTF XML format for storing the data. EMTF FCU v4.1 software consists of a set of freely available format conversion tools that can - News