Figure 1 The Norwegian continental shelf is divided into eleven geographical regions for the regional sediment monitoring. Each region is surveyed every third year with surveys alternating between regions. The fields investigated for naturally occurring radionuclides in 2024 (Heidrun, Draugen, Njord, Grane, Ivar Aasen and Edvard Grieg) are marked. The regional stations are shown but not marked.