The Seed Vault has the capacity to store 4,5 million different seed samples. Each sample will contain on average 500 seeds, so a maximum of 2,25 billion seeds may be stored in the Seed Vault. The Seed Vault will therefore have the capacity to hold all the unique seed samples that are conserved today by all the approximately 1400 genebanks that are found in more than 100 countries all over the world. In addition the Seed Vault will have capacity to also store many new seed samples that may be collected in the future.
When in full use, the Svalbard Global Seed Vault will represent the world’s largest collection of seeds.
Svalbard has an isolated position far out in the ocean, between 74° and 81° N and only 1000 kilometres from the North Pole. The archipelago is characterised by an undisturbed nature. Permafrost provides stable storage conditions for seeds. Besides which there is little risk of local dispersion of seed.
Also, presumably because Svalbard is the only place the vault can be guarded by armored bears.