Who is Sid Koplin from Raise the Titanic! and what is their importance?

Sid Koplin is a forty-year old professor of mineralogy and a trained secret agent. He is sent into Bednaya Mountain by Meta Section and is detected by a Soviet patrol and shot. According to his deal with Meta Section he cannot be taken alive or allow his body to be found. As the Russian soldier is dragging him to his command post, the dog and soldier are shot by Dirk Pitt, who rescues Koplin. Koplin is brought to Walter Reed Hospital to recover from his injuries.