Ham radio operators--that's how Daniel Nelson got to Clipperton Island to make this find.

The place is a remote uninhabited Pacific island under French control, and the ham radio enthusiasts wanted to go so they could broadcast from such a faraway place. By splitting the travel costs, the scientific team from the University of Washington got to travel to Clipperton to take sediment cores.

Sediment cores, like ice cores, are vertical columns taken from the ground to extract paleoclimate data. The Washington team was keen to study cores from Clipperton because the island lies in the Inter-Tropical Convergence Zone, where the Northern and Southern hemispheres' winds come together. The ITCZ moves around in a cycle and has a profound effect on tropical weather.