Dr. Shûzô Yoshizumi
Yasuo Tatsuno
Cmdr. Nakanishi (as Isao Natsuki)
Dr. Yamauchi (as Sonny Chiba)
Ryûji Sanazawa
Akimasa Matsuo
Team Member - Showa Station
Team Member - Showa Station (as Chû Takatsuki)
Team Member - Showa Station (as Riki Gonoue)
Adm. Conway
Maj. Carter
Sarah Baker
Secretary - Palmer Station
Secretary - Palmer Station (as Patto Regô)
Radio Operator - Palmer Station
Dr. Borodinov
Capt. Nevsky
Marit
Girl
Capt. Lopez (as Edward J. Olmos)
Dr. Latour (as Cecil Linder)
Dr. Irma Ollich
Dr. Turowicz
Maj. Giron (as Ara Hovanessian)
Dr. Baines
Maj. King
Radio Operator 'Ahab' - Mawson Station
Capt. McCloud - HMS Nereid
Lt. Jones - HMS Nereid (as Ken Camroux)
Navigator - HMS Nereid
Radio Operator - HMS Nereid (as Gordon Thompson)
Sailor #1 - HMS Nereid
Sailor #2 - HMS Nereid (as Alfred Humphreys)
Young Sailor - HMS Nereid
Ens. Smirnov - Soviet Submarine T222
Sonar Operator - Soviet Submarine T222
Noriko Asami
Yoshiko Tatsuno
Akira Tatsuno
Prof. Tsuchiya
Dr. Tadokoro
Intern #1 - Tokyo
Intern #2 - Tokyo
Nurse - Tokyo
Nurse - Tokyo (as Sachiko Satô)
Young Mother - Tokyo
Daughter - Tokyo
President Richardson
Sen. Barkley
Gen. Garland
Secretary of State Reid
Secretary of Defense Morrison
Secretary of Health Watt
White House Aide Simmons
Col. Rankin
Dr. Ed Meyer
Dr. Rogers (as Ron Hartman)
Orderly #1
Orderly #2
Rankin's Driver
Spy Z
Big Man
Little Man
Pilot
Cossack Boy
Dr. Krause
Sentry - East Germany
Military Police Officer - East Germany
Military Policeman - East Germany (as Wally Bondarenko)
TV Narrator (voice)
Toby Anderson (voice)
Alvaro Espinoza (uncredited)
UN Delegate (uncredited)
Scientist (uncredited)
Litha (uncredited)