Deep Fathom

Deep Fathom is a novel by James Rollins.

Synopsis
Ex-Navy SEAL Jack Kirkland surfaces from an aborted underwater salvage mission to find the earth burning. Solar flares have triggered a series of gargantuan natural disasters. Earthquakes and hellfire rock the globe. Air Force One has vanished from the skies with America's president on board. Now, with the U.S. on the narrow brink of nuclear apocalypse, Kirkland must pilot his oceangoing exploration ship, Deep Fathom, on a desperate mission miles below the ocean's surface. There devastating secrets await him - and a power an ancient civilization could not contain has been cast out into modern day. And it will forever alter a world that's already racing toward its own destruction.

Jack Kirkland
An ex-navy SEAL who placed a satellite into space, the trip cost his crew on the shuttle their lives; he was the only survivor.

Karen Grace
A Canadian professor who first finds the writings. Her grandfather (James Churchward) had theorized about the lost continent, but she found it.