My story takes place with hikers high in the mountains of South America. Today I learned about the South Atlantic Anomaly.


This region, which covers most of the continent of South America, is said to be reliably responsible for computer crashes in space, when vehicles pass through the region.

I can not find any published work estimating what the South American Anomaly does to people on the ground : computers, radio, magnetic navigation, GPS navigation.

What will my hikers experience on the ground under the South Atlantic Anomaly? Southern Lights? Will their computer equipment, compasses, and GPS function normally?

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    $\begingroup$ What is the worldbuilding problem here? It sounds like a legitimate question for Earth Science $\endgroup$
    – L.Dutch
    Jun 13 at 17:25
  • $\begingroup$ Why would you expect that something which happens in outer space would have any effects whatsoever on the ground? The "anomaly" is simply the area where the inner Van Allen radiation belt comes closest to the surface (on the average), with a small but measurable effect on low Earth orbit satellites. It is still some 200 km above the surface. (I put "anomaly" in scare quotes because, given that Earth's magnetic dipole is not concentric with the planet, pure geometry says that there must be some area where the radiation belts come closer to the surface than the average.) $\endgroup$
    – AlexP
    Jun 13 at 17:51
  • $\begingroup$ Excellent question. Unfortunately, I do not believe this fits the qualifications for this site. Perhaps you can find another StackExchange site to post this on? $\endgroup$
    – Wyvern123
    Jun 13 at 17:55
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    $\begingroup$ Is there any source saying that GPS devices don't work in Argentina? $\endgroup$
    – AlexP
    Jun 13 at 18:15
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    $\begingroup$ This is a story in search of a problem to solve. Perhaps ask yourself what you want to happen, then we can help you devise a way of justifying it by science - at the moment it's NAW. $\endgroup$ Jun 13 at 23:27

1 Answer 1


You will see more radiation damage to devices, but the chances for disruption are still relatively low. And most of your devices are somewhat resilient at the system level, or can be reset so even if you have an event it may not matter. You can have hard errors and soft errors and device killers. The device or system killers are more rare than soft or hard errors. A soft error can be reset.

The anomaly is also more centered out in the ocean, so may be a less of a problem due to its location. However it does move around and is fairly big area depending on how you use it.

The above comment is based on looking at some LEO satellite data where upsets for different types of electronics were plotted as a function of position. You could see from the data that there were more problems when passing over the anomaly, but not so severe that everything didn’t work because it passed over the anomaly. A lot of space craft spend some time passing through that area every so often depending on the orbit. If the satellite is planned to go though that area there can be more shielding or you can operate your equipment differently. So it is a real consideration for space craft..

For you people on the ground there is a lot more atmosphere so the problem would be even less. The atmosphere will shield a lot of the radiation effects. At higher altitudes you will have more radiation. For spacecraft trapped electrons and protons van Allen belt stuff is part of the anomaly problem. The atmosphere reduces that type of radiation even more. For cosmic rays and high energy particles maybe some more in the anomaly region, but since those particles are so energetic the anomaly may not influence them that much. That may be a research topic.

However, I would let that stop you from using it as a story element. Some devices and systems are more susceptible and will fail with a particle going through the wrong part of the device.

Edit: after doing a little more research

This effect is not only problematic at high altitude, where the satellites or other objects orbiting around the Earth are affected by a high density of cosmic ray particles, but also at surface level, where the communications can be disturbed due to the induced currents in transmission lines during geomagnetic storms.

So some concern when combined with a solar flare due to less protection in that area.

Also the anomaly has move significantly westward and is centered more over land now.


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