(NATURE) — One hundred thousand years ago, a massive chunk of the Mauna Loa volcano cracked away from Hawaii and slid into the sea, launching a wave that rose as high as the Eiffel tower up the slopes of a nearby island.
That mega-tsunami was not an isolated incident: the past 40,000 years have seen at least ten gigantic landslides of more than 100 cubic kilometres in the North Atlantic ocean alone, each capable of producing waves tens to hundreds of metres high. Another is bound to happen sometime — although whether it will strike tomorrow or 10,000 years from now is anyone’s guess.
This week, the World Economic Forum published its 2013 global risks report, which includes a section, produced in collaboration with Nature, on X factors: low-probability, high-impact risks resulting mainly from human activity (see go.nature.com/outhzr). But the natural world holds unpredictable threats as well. The geologic record is peppered with evidence of rare, monstrous disasters, ranging from asteroid impacts to supervolcanoes to γ-ray bursts. Nature looks into some of the life-shattering events that Earth and the broader Universe could throw our way.