Product catalogue
Modeling Geoelectric Fields Induced by Geomagnetic Disturbances in 3D Subsurface Geology, an Example from Southeastern Australia
Abstract:
Geomagnetic storms can cause power grid instabilities and blackouts due to excessive geomagnetically induced currents (GICs) flowing in electric transmission systems. In this study, we assess regional vulnerability to GICs by modeling the geoelectric fields induced by significant historic geomagnetic disturbance events in the presence of 3D subsurface geology using data from the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) magnetotelluric array, Australia‐Wide Array of Geomagnetic Stations (AWAGS) magnetometer array, and Geoscience Australia geomagnetic observatory network. We analyze the vertical component of the magnetic field with respect to the horizontal magnetic‐field polarization for two magnetic storms and gain insight into the inductive effects associated with field polarization orientations in the 3D case. We also analyze the telluric field intensity and polarization for a unit geomagnetic field polarized in northerly and easterly directions at AusLAMP sites and find that in the presence of 3D geology the induced field has a very polarization‐sensitive anomaly. We model the geoelectric fields in southeastern Australia for the 1989 “Québec storm.” The induced ground electric fields are typically in the range 1,000–2,000 mV/km with a few sites within 2,000–5,000 mV/km on highly resistive regions and in coastal areas, and below 300 mV/km on inland sedimentary basins. The current study focuses on magnetic field variations with periods between 120 and ~20,000 s due to bandwidth limits in our magnetotelluric tensor data and the Nyquist limit for the 60 s sampling of our geomagnetic‐field data. Hence, our modeled maximum values should be considered lower estimates of potential real values.
Plain Language Summary:
We assess Australia's vulnerability to electric currents caused by geomagnetic storms. We use data from recent and historic geophysical studies to represent a range of possible geomagnetic‐field variations (including the extreme 1989 “Québec storm” event), and we use a three‐dimensional mathematical representation of the electrical conductivity of Australia's regional geology to represent the natural conductors in which electric currents can flow. Our analysis shows that the spatial variability of ground electric currents that can be caused by geomagnetic storms is closely associated with geologic structure. We find that ground electric currents are stronger in places where there are large differences between the conductivities of subsurface geologic structures. These include, for example, electrically resistive rocks near coastlines that are adjacent to deep and highly conductive oceans or, inland, where there are big contrasts between the electrical conductivities of different rock types. Away from such natural differences in electrical conductivity ground electric currents tend to be weaker. Every country on Earth has different types of rock that make up its geology, and many countries are bounded by an ocean. Vulnerability to electric currents caused by geomagnetic storms is an increasingly important issue, particularly in light of the mushrooming reliance of societies on high‐tech solutions to modern needs. The method we have developed for this research is readily extensible to other places to assess the risk posed by ground electric currents.
<b>Citation:</b> Wang, L., Duan, J., Hitchman, A. P., Lewis, A. M., & Jones, W. V. (2020). Modeling geoelectric fields induced by geomagnetic disturbances in 3D subsurface geology, an example from Southeastern Australia. <i>Journal of Geophysical Research: Solid Earth</i>, 125, e2020JB019843. https://doi.org/10.1029/2020JB019843
Simple
Identification info
- Date (Creation)
- 2020-03-13
- Date (Publication)
- 2024-02-08T00:47:16
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/135025
Identifier
- Codespace
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Digital Obejct Identifier
- Cited responsible party
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Role Organisation / Individual Name Details Author Wang, L.
Place and Communities Division Internal Contact Author Duan, J.
MEG Internal Contact Author Hitchman, A.
MEG Internal Contact Author Lewis, A.
Place and Communities Internal Contact Author Jones, W.V.
External Contact Publisher AGU Publications
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Journal of Geophysical Research: Solid Earth
- Issue identification
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Volume 125, Issue 9. September 2020, e2020JB019843
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Published in 2020
Research article for Journal of Geophysical Research - Solid Earth - Geomagnetism
- Status
- Completed
- Point of contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Resource provider Place and Communities Division
External Contact Point of contact Wang, L.
Place and Communities Division Internal Contact
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- Geoscientific information
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))
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Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes
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EARTH SCIENCES
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- Keywords
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induced electrical fields
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geomagnetic disturbances
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geomagnetic induction hazard
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polarization orientation
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Published_External
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Creative Commons Attribution 4.0 International Licence
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CC-BY
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4.0
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c) Commonwealth of Australia (Geoscience Australia) 2020
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Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
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- Unclassified
- Language
- English
- Character encoding
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Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
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Link to Journal
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Australian Government Security Classification System
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- 2018-11-01T00:00:00
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Metadata
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urn:uuid/ede1eaa5-c82a-40d3-985b-52cbcb69ad88
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GeoNetwork UUID
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- Contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Owner Wang, L.
Place and Communities Division Internal Contact Point of contact Wang, L.
Place and Communities Division Internal Contact
Type of resource
- Resource scope
- Document
- Name
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Journal Article
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Geoscience Australia - short identifier for metadata record with
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- eCatId/135025
- Date info (Creation)
- 2020-03-13T02:37:56
- Date info (Revision)
- 2020-03-13T02:37:56
Metadata standard
- Title
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AU/NZS ISO 19115-1:2014
Metadata standard
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ISO 19115-1:2014
Metadata standard
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ISO 19115-3
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Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
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Version 2.0, September 2018
- Citation identifier
- https://pid.geoscience.gov.au/dataset/ga/135025