POLLUTANT PATHWAYS BETWEEN MURUROA AND OTHER POLYNESIAN ISLANDS, BASED ON NUMERICAL-MODEL TRAJECTORIES

We address the question of which Polynesian islands would be most vuln erable to exposure from radionuclide material as a result of past nucl ear testing at Mururoa and Fangataufa, should some of the material now stored in the atolls find its way into the ocean, We use an ocean cir culation model of the Polynesian region with 26.5 km resolution and fo ur open boundaries to find advective pathways from Mururoa to other is lands. The model is driven by monthly mean wind stress and by the larg e-scale circulation determined from the wind stress curl at the northe rn and southern boundaries, Surface trajectories vary strongly with th e seasons but always indicate southward or south-westward movement. Tr ajectories at 50 m and 100 m follow the South Equatorial Current westw ard. According to the model, no islands in the main island groups nort h of the latitude of Mururoa (22 degrees S) are on a direct (advective ) pathway with Mururoa or Fangataufa at any time, The islands most in danger of exposure to material from the two nuclear test sites are tho se in the Austral Group. (C) 1998 Elsevier Science Ltd. All rights res erved.