Peter A. Rona, an oceanographer who dived into the depths of the world’s seas and surprised his peers by discovering vast mounds spewing hot smoke at the bottom of the icy Atlantic, exciting interests in deep-sea mining and the origins of life on earth, died on Feb. 20 in Plainsboro, N.J. He was 79. The cause was complications related to multiple myeloma, according to Rutgers University, where Dr. Rona was a professor of earth and planetary sciences. Fascinated by the mysteries of what he called “the last frontier on earth,” Dr. Rona specialized in exploring the dark abyss for more than a half-century, starting around 1960…”I was one of those kids who collected rocks and minerals, climbed mountains, loved the outdoors and identified with geology,” he told a Rutgers publication.