There are occasional community discussions about how to preserve Wikipedia
(and hopefully the sister projects) for a very long time even if there are
any of several kinds of global disasters. This archival technology might be
of interest:
http://phys.org/news/2016-02-eternal-5d-storage-history-humankind.html
Quoting from the article: "As a very stable and safe form of portable
memory, the technology could be highly useful for organisations with big
archives, such as national archives, museums and libraries, to preserve
their information and records."
I haven't studied this technology in any depth so I can't endorse it, but
it looks like it might be of interest to archivists, preservationists, and
contingency planners.
Pine