The powerful magnitude-8.6 earthquake that shook Sumatra on April 11, 2012, was the largest strike-slip quake ever recorded. Now, as researchers report on their findings from the first high-resolution observations of the underwater temblor, they point out that the earthquake was also unusually complex — rupturing along multiple faults that lie at nearly right angles to one another, as though racing through a maze.

Humans get most of the blame for climate change with little attention paid to the contribution of other natural forces. Now, scientists are shedding light on one potential cause of the cooling trend of the past 45 million years that has everything to do with the chemistry of the world’s oceans.