> local electromagnetic event then I'd prefer to have a backup that can handle that.
First of all, the magnetic gauss needed to flip bits on LTO media is huge. It's not a practical concern unless you're choosing an incredibly inappropriate storage location.
Second, why wouldn't you store your tapes in a case or a vault that is magnetically shielded?
You probably store your discs in cases, instead of insisting they be naturally durable against rough handling and abrasion.
> First of all, the magnetic gauss needed to flip bits on LTO media is huge. It's not a practical concern unless you're choosing an incredibly inappropriate storage location.
(Some of the links from this answer are quite interesting.)
The issue is that I don't know (and I suspect it's difficult to know or even classified) whether an EMP attack (the main scenario I'm worried about, which can be quite powerful) would be sufficient to cause damage. I don't believe there is a consensus on this though I'd be glad to be proved wrong here.
> why wouldn't you store your tapes in a case or a vault that is magnetically shielded?
I would; as I said I put some magnetic hard drives in Faraday cages. However, I'm not confident that the Faraday cage would be sufficient. A lot of the discussion online about constructing Faraday cages to protect electronics is speculation. I haven't seen any clear data showing that during an EMP attack magnetic data is protected inside of a Faraday cage, or protected without one.
The EMP from a nuclear weapon is mostly radio frequency and would be picked up by antennas, power lines and such. (I know an ex-military ham who always unplugs his HF/shortwave radio from the antenna and power when he's not using it because that's what they taught him to do back in the day.)
I don't see that kind of EMP erasing magnetic media.
First of all, the magnetic gauss needed to flip bits on LTO media is huge. It's not a practical concern unless you're choosing an incredibly inappropriate storage location.
Second, why wouldn't you store your tapes in a case or a vault that is magnetically shielded?
You probably store your discs in cases, instead of insisting they be naturally durable against rough handling and abrasion.