Deep beneath the ocean floor off the New Jersey coast lie secrets that could help scientists predict how climate change might affect one of the most popular shorelines in the country. Gregory Mountain, with a name that befits his expertise, teaches Earth and planetary sciences and has spent a lot of time in recent years sailing those waters to uncover the answers. “This is . . . to understand better what the future is going to hold,” said Mountain, a professor at Rutgers University in New Jersey. “The future that is within our grandchildren’s time.”