Every day last summer, Jónína Ólafsdóttir did the same thing. Early in the morning, she’d haul about 300 pounds of Scuba diving equipment into her car, then she’d drive out to Thingvellir National Park, one of Iceland’s many untouched places, about an hour’s drive north of Reykjavik. With her waterproof wetsuit, she’d plunge into the frigid water and descend to scrape samples of dirt off the walls into small canisters. An hour later, she’d surface with numb hands and purple lips. Then she’d drive back south to bring the samples to the lab.

Ebullient and soft spoken, Jónína doesn’t look like the toughest person you’ve ever met. But Jónína is Icelandic and Icelanders have a strength in their genes. “Do you want me