Final Frontier: The Atlantis Chronicles

Sam is getting ready to start a new life in the marine city of New Atlantis. Like any kid her age, moving is not something she's been looking forward to: New schools, new classmates, new house. Her only consolation is that her father will be much closer to his job and hopefully won't have to travel as much.
As she begins to settle into this strange new city she meets a group of kids her age living in the same habitat as her.
Being the children of important scientists, they often overhear information and gossip and as they act on the information they learn they begin to uncover a plot: One that could put the entire city - And everyone Sam loves - in deadly peril.
Racing against the clock Sam and her friends must uncover the truth of an old disaster and prevent it from happening again. Will they succeed? Or will New Atlantis vanish into the depths of the ocean like its ancient namesake?