USGS - Geomagnetic Hazard Study

[Astronuc]

We have various threads and posts on the topic of the Earth's magnetic field. Now, "a new mapping effort by the US Geological Survey (USGS) shows how the hazards of geomagnetic storms are not the same all over Earth — and they're especially worrisome in northern Minnesota," and particularly up by the Canadian border, which I would expect means that parts of southern Canada, e.g., Western Ontario and Southern Manitoba would be similarly susceptible.

To generate the US-wide geomagnetic storm hazard map, Love and his team merged two important sets of data.

One was several decades' worth of geomagnetic storm measurements, taken by monitoring stations all over the nation. The other was an ongoing "magnetotelluric" survey.

During a magnetotelluric survey, crews stick big electrodes into the soil, record the signal with recording machines, and move the stations over a large area for several weeks. The data they pick up reveals how rock layers, the water table, and other factors deep underground affect the conductivity of that region — and, in step, how much electricity a geomagnetic storm can induce there.

Here's an older 2015 publication - http://geomag.usgs.gov/downloads/publications/Bedrosian_et_al-Geophysical_Research_Letters.pdf

Geoelectric hazard maps for the continental United States
http://onlinelibrary.wiley.com/doi/10.1002/2016GL070469/epdf

http://geomag.usgs.gov/

I presume there is a similar effort in Canada.

 

[Greg Bernhardt]

and they're especially worrisome in northern Minnesota," and particularly up by the Canadian border,

For the power grid or something else?

 

[Astronuc]

For the power grid or something else?

The concern is about the response to a large disturbance from the sun and its impact on the grid(s).

Canada has a similar program.
http://geomag.nrcan.gc.ca/lab/default-en.php

I would expect some coordination between NRCan and USGS, but it's not apparent.

 

[Greg Bernhardt]

The concern is about the response to a large disturbance from the sun and its impact on the grid(s).

What exactly can be done? Better shielding?

 

[CapnGranite]

http://dme.engin.umich.edu/spaceweather/ A story about a disaster
http://phys.org/news/2016-09-regional-solar-storm.html
Regional solar storm forecasts set to begin

Magnetotelluric surveying has come a long way from being a stepchild tool in geophysics, with a seemingly limited utility. I last used magnetotelluric surveying in 1996 to define groundwater sub-basins in Monterey County CA. I was more than impressed with the detail. As shown in the original post, its come into its own. What I would do next with the existing magnetotelluric data is to search for discontinuities or breaks in the impedance to see if areas at risk of high spikes are isolated . Coupled with the regional solar storm data, local rather than regional high-risk portions of the power grid might be isolated. This would assist the "Power Grid" people in determining what to do using the current plans. I on't know, but I suspect a shield is a way off, and we are left with mitigation. That mitigation is helped with the data on crustal responses to a solar storm.

 

[CapnGranite]

ON GEOMAGNETIC STORMS IN GENERAL:
http://onlinelibrary.wiley.com/doi/10.1002/2016SW001411/abstract
Analysis of the monitoring data of geomagnetic storm interference in the electrification system of a high-speed railway
Abstract
To study the impact of geomagnetic storm on the equipment of traction electrification system in the high-speed railway, geomagnetically induced current (GIC) monitoring devices were installed in the Hebi East traction power supply substation of the Beijing-Hong Kong Dedicated Passenger Line in January 2015, and GICs were captured during the two geomagnetic storms on 17 March and 23 June 2015. In order to investigate the GIC flow path, both in the track circuit and in the traction network adopting the autotransformer feeding system, a GIC monitor plan was proposed for the electrical system in the Hebi East traction power supply substation. This paper analyzes the correlation between the GIC captured on 17 March and the geomagnetic data obtained from the Malingshan Geomagnetic Observatory and presents a regression analysis between the measured GIC and the calculated geoelectric fields on 23 June in the high-speed railway. The maximum GICs measured in the track circuit are 1.08 A and 1.74 A during the two geomagnetic storms. We find that it is necessary to pay attention on the throttle transformers and track circuits, as the most sensitive elements responding to the extreme geomagnetic storms in the high-speed railway.