Summary
This piece describes some ways to back up your most important electronic data against the risk of electromagnetic disasters. Since "NASA puts the likelihood of [...] a geomagnetic super-storm at 12 percent per decade", the expected benefit of making these backups seems worth the cost.
My current recommendation for backups:
- Use a form of optical data storage, such as Blu-ray discs.
- Also store the data in the cloud so that your data won't just be in one location.
- For really important documents, also consider paper backups.
Note
I don't understand the physics of this topic, and what I write in this piece may be misguided. I've just cobbled together some advice from various (sometimes contradictory) sources. For now, until I learn more about this topic, I think it makes sense to use at least one non-electricity-based form of storage (such as optical media or paper) for important data, as a precaution. In addition, even if hard drives and flash drives aren't vulnerable to large-scale magnetic disasters, they can still be damaged by more mundane and small-scale electrical problems, like voltage surges in your power lines (when connected to a plugged-in computer) or electrostatic discharge when handling them.
Types of disasters
Geomagnetic storm
This article reports:
According to [former Director of Central Intelligence James] Woolsey, a solar super-storm like the Carrington Event today would “collapse electric grids and life-sustaining critical infrastructures worldwide, putting at risk the lives of billions.”
Of course, if a geomagnetic storm was bad enough that society collapsed, then my writings would be less useful than in scenarios where that doesn't happen.
This article quotes "Doug Biesecker of the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center" as saying:
The possibility of an extreme [coronal mass ejection] CME causing a very powerful geomagnetic storm is real. There’s considerable uncertainty to how frequent such storms are at the level where we worry about huge impacts on the power grid and the resulting impacts that a lack of electricity would have. Is it a 1 in 50, 1 in 100, or 1 in 1,000 year event? We just don’t know.
Verge (2013) reports the recommendations of Eric Gallant: "For data center providers, Gallant urges taking precautions to prevent damage resulting from small or mid-sized solar flares. This includes installing transient voltage surge suppression (TVSS), uninterruptible power supplies (UPS), and on-site emergency standby generators." How common are TVSSs in data centers? Can data be lost if they're not in place?
On the thread Super User (2016), some people suggest there's not much risk of losing hard-drive data to a geomagnetic storm. One comment says: "A geomagnetic storm powerful enough to erase a hard drive will be accompanied by a CME powerful enough to strip the atmosphere off the Earth. [...] In order to cause magnetic effects on a hard drive, you'd need a magnetic field at least 100,000 times more powerful than the one that accompanied the 1989 geomagnetic storm". Another person says: "I have a hard time taking this question seriously[...]. A flare powerful enough to overwrite your HDD will alter Earth's magnetic field badly enough to let solar radiation through."
EMPs
An electromagnetic pulse (EMP) attack could potentially destroy electronic equipment in a wide region of the US. The probability of such an attack happening in my lifetime seems pretty low but maybe not less than a few percent?
Thibodeau (2014) discusses a company opening a data center that "has been purpose-built to protect against an electromagnetic pulse (EMP), either generated by a solar storm or a nuclear event." This suggests that most data centers aren't protected? Thibodeau (2014) says:
Domich said the idea for the EMP-resistant data center came from a customer, an insurer, that wanted to protect its data from electromagnetic pulses.
An EMP can "irrevocably destroy" data, said Domich. The magnetic field on a disk that is used to set the data, if not maintained, or if it is abruptly or intensely changed, will wipe out the data, he said.
EMP GRID Services describes an "EMP Resilient Center".
Almost no data centers are EMP-proof, so if Google/Facebook/etc. had only one copy of your data (do they?) and it was stored in an affected data center, the data would presumably be lost? Maybe this isn't true for data centers using optical storage, such as Facebook's Blu-ray data centers (Metz 2016)? Or when most people say data centers aren't protected against EMPs, are they merely saying that the data-center would go offline, not that the data itself would be erased?
Google explains that "Rather than storing each user's data on a single machine or set of machines, we distribute all data — including our own — across many computers in different locations." But given that many of Google's data centers are in the USA, I wonder if the replicated copies of US customers' data are all in the USA and hence vulnerable to a USA-wide EMP?
EMPs can be worse than solar storms
Clark (2013) seems to imply that EMPs are more likely than solar disasters to damage computer hardware:
Although direct damage to electronics in the style of an electromagnetic pulse (EMP—one of the “side effects” of a nuclear blast) owing to a solar flare is conceivable, it is less likely. “An EMP is a sudden, high-intensity event, whereas a solar storm is a longer-duration, lower-intensity event. Because of these different electrical characteristics, solar storms will typically only generate currents in very long (300 km+) conductors. Hence, technologies that are vulnerable to solar-storm damage include large systems, such as electrical grids, transcontinental pipelines and telephone systems,” said Gallant. “As a result, the electrical and communication systems that data centers depend on are much more likely to be affected by a solar storm than the data center IT infrastructure itself.”
The accepted answer on Super User (2016) explains:
A geomagnetic storm shares some properties with, but it is not, an EMP. Or better: what we think of as an EMP is a very localized phenomenon, which at relatively close range has energies orders of magnitude above the ones of a CM[E] that happened 150 million kilometers away from the Earth.
So an EMP like STARFISH PRIME's would trash your equipment if it happened within a few (tens of?) kilometers, depending on shielding. A geomagnetic storm will induce currents that are proportional to the length of the conductor coil. While this is very bad if you're a power station connected to a 500 km set of wires, it is next to harmless if you're a home PC no wider than a few tens of inches.
Hedge fund manager Paul Singer wrote in an investment-update letter warning about electromagnetic disasters that a deliberate EMP attack "would not cause any blast or radiation damage, but such an attack would have consequences even more catastrophic than a severe solar storm. It could not only bring down the grid, but also lay down a very intense, very fast pulse across the continent, damaging or destroying electronic switches, devices, computers and transformers across America" (Delevingne 2014).
Woolsey and Pry (2015): "Nuclear EMP is worse than natural EMP and the EMP from [Radio-Frequency Weapons] RFWs because it combines several threats in one. Nuclear EMP has a long-wavelength component like a geomagnetic super-storm, a short-wavelength component like Radio-Frequency Weapons, a mid-wavelength component like lightning--and is potentially more powerful and can do deeper damage than all three."
Backup options
Backup across continents
For a local EMP, one solution could be to have a friend on another continent back up an extra copy of your data. One answer on Super User (2016) recommends this kind of solution, but only for "Events much less severe as the Carrington event".
Woolsey and Pry (2015) say "The Carrington Event was a worldwide phenomenon". Does this mean that a Carrington-sized storm would cause severe damage worldwide? Or would it still be mostly concentrated on one side of the planet?
Is a flash drive enough?
This article says that "A flash drive stored well away from any external electrical lines would very likely survive an EMP strike." One commenter on this thread echoes that "Flash drives and optical disks would be completely safe too." However, other people on that thread use Faraday cages—is that because Faraday cages actually are necessary to protect a flash drive?
Here are some more sources suggesting that storage media disconnected from anything else would likely survive even an EMP:
- Reddit ("Protect ..."): "Your unplugged USB stick is likely safe period, because the short traces will not pick up much induced current-- and even if they do it will likely be recoverable from the raw flash."
- Reddit ("would ..."):
EMPs need a long wire to induce voltage into the object. Anything connected to a long wire like a powerline is done. Just forget about it.
Any device with long wires inside it is also likely to induce a very high voltage into itself and fry its circuits, so older electronics tend to fare very poorly.
New electronics with very short runs of wire in them tend not to be affected. I'd guess that its very unlikely a usb has enough wiring to actually generate a high voltage in an emp. It may corrupt the memory or something, but physically it should be fine.
Any hard memory would be more resilient. An unplugged hard drive would probably be completely fine.
Meanwhile, here are some sources suggesting that it's unclear if even disconnected devices would survive:
- Jorgustin (2012-2017): "even if the electronic device is NOT plugged in, it will also be vulnerable to the effects of the EMP as the invisible pulse radiates outwards through the air, enveloping everything in its path (except for those items which are protected in a Faraday type cage or similar). Again, the degree of damage will depend on your proximity, and other factors."
- Quora ("Can EMP ..."): Regarding the question "Can EMP damage devices that are disconnected from their power supplies?", Christopher Mortell says: "The working answer is simply yes. The metal in the device would act as an antenna. Any device you want to protect should be in a Faraday cage."
- Super User ("Are unpowered ..."): "As others have mentioned, your SSD is susceptible to EMP while under power. unfourtunately, it looks like it is vulnerable, in many cases, while unplugged as well."
Faraday cages
TODO: I plan to look more into how to buy a Faraday cage.
One concern I've seen discussed is that the cage itself my destroy the contents of a flash drive. So it seems prudent to have two copies of your data: one on a flash drive stored in a Faraday cage, and one on a flash drive not in a Faraday cage.
One answer on Super User (2016) says that for big enough geomagnetic storms: "Theoretically, if your Faraday cage is good enough (enough layers, thick enough conducting layers), it might pull it off. But I'm not sure if that will work with such violent events."
Optical storage (CDs, DVDs)
Someone on this forum suggests: "Files can be put in encrypted 7z archives before giving to friends to store. as a CD is an optical medium (hard drives are magnetic, USB drives use 'flash memory') it can survive electromagnetic hazards better than other types of storage, it ought to survive EMP or CME."
One answer in Super User (2016) says that CD/DVD storage is "The best solution" and would work even for "Events similar or bigger than the Carrington event".
Many new laptops don't have CD drives, but you can buy an external USB drive.
Unfortunately, regular CDs/DVDs don't last indefinitely:
It is hard to predict exactly how long an optical disc will last since it depends on so many different factors. Nevertheless, estimations are floating around that predict a life span of up to 200 years for recorded CD-Rs and Blu-Ray discs. The shortest life span with 5-10 years is predicted for unrecorded CD-Rs and CD-RWs, followed by recorded DVD-RWs with up to 30 years. Recorded CD-RWs and DVD-Rs have a predicted lifetime of 20-100 years. In other words, you should not rely on any of these media for lifelong storage of your precious data, as they are likely to fail sooner rather than later.
M-DISC and Blu-ray
The longevity problems of regular optical disks are overcome by the M-DISC, which claims to last 1000 years. This article says that the M-DISCs tested could be read by 6 out of 8 of the DVD drives tested. However, a comment on that article claims that "MDISC is mostly marketing hype" and "the government recognizes that standard Blu-Ray are just as acceptable."
This article says "If you’re worried about optical drives disappearing, know that optical retains a very strong presence in the archival community, as well as the enterprise, so that should give you some reassurance."
The MDISC Archive Service is one way to preserve your data on M-DISCs. For $89 per year, the service will gather your data from the cloud and send you one or more discs containing the data every month. Since these discs are sent in the mail, you should make sure that any sensitive data is encrypted, in case the disc gets lost in the mail or a nosy fellow apartment dweller steals your shipmenta. While I tried this service for a while, I later switched to manually backing up my data on Blu-ray discs because
- Creating new discs of roughly the same data every month seems excessive. Over time, you'll have to keep track of a mounting pile of discs, and securely disposing of them later will be a pain. I think backing up to optical storage once every few years is sufficient.
- The M-DISC shipments were sometimes "flaky": not shipping during one month, shipping more than once during another month, not always including all of my data on the discs, etc.
I now use this Blu-ray burner and these blank Blu-ray discs (50 GB each). [TODO: I should probably look into buying archival-grade discs in the future.] You could also burn to DVDs/etc, but Blu-ray discs can hold more data per disc. Even if Blu-ray discs won't last 1000 years, as long as you're making new backups regularly, the latest backups you make will probably last several years—long enough to get through an electromagnetic disaster.
I wrote more about Blu-ray discs in "Archiving data on Blu-ray discs".
Printing out on paper
You can collect the texts that you most want to save and have them printed out (probably by a professional printing service to avoid wearing out your home printer). Printed pages can get lost, may burn up in a house fire, etc., but their risks are pretty complementary to the risks that electronic data storage faces. (It's good to have at least one cloud backup and at least one in-your-home backup.)
Paper is nice because it avoids "black swans" of digital preservation—not just geomagnetic storms but also bit rot, format rot, lack of electricity, etc. Paper copies of documents aren't as flexible as digital data, but the pages could be scanned back to electronic format and converted to text using OCR if need be.
A Reddit comment says:
If you have data in text files that will not change, old school low tech printing it on paper with a laser printer and NOT an inkjet printer works great. Paper, under the proper storage conditions has been known to survive hundreds and in some cases, thousands of years. If you need to get it back into a computer in digital form, you can use OCR to re-digitize it quickly and accurately.
For a how-to guide on paper website backups, see "Backing Up a WordPress Website on Paper".
Backing up other people's websites
Internet Archive?
Usually you can get backups of other people's websites through Internet Archive. But would Internet Archive's data survive a Carrington Event-scale geomagnetic storm?
The answer here says "The main Internet Archive storage is a custom technology called the PetaBox, which is now in its second generation. It’s designed and built from the bottom up and the inside out to be pretty robust." But I'm currently not sure whether PetaBox storage would be resistant to a Carrington Event. (I'd like to explore this further.)
This answer, regarding Internet Archive's protection against EMPs, says Internet Archive uses "Globally distributed backups." But I'm not sure if this is sufficient protection against a Carrington Event.
There also remains some risk that Internet Archive will go away eventually, perhaps due to lack of funding, though one hopes that its content would remain accessible to those willing to pay for access. And Internet Archive doesn't always have 100% coverage of pages on a given domain.
Doing your own backups
In order to be on the safe side, I do my own backups of websites whose content I consider important. Many entire websites are less than 1 GB when compressed, which makes backing up hundreds of them potentially feasible, given that the M-DISC service mentioned above has a huge size limit: "The overall limit for our $8 [per month] plan is 1TB of data per year. If you plan to upload more than that in a year, we suggest you consider our Pro Plan".
This page gives some details about doing website downloads to back up other people's websites (or your own website).
Footnotes
- M-DISC backups are occasionally sent in big packages that include "photo album"-type holders for the discs, and at least those would probably end up in an apartment package-pickup room rather than a personal mailbox. (back)