Underwater sound recordings were made from the Noble Kolskaya jack-up gas-exploration drilling-rig in the German region of the Dogger Bank, North Sea. The aim was to document received levels, characteristics, and range-dependence of sounds produced by the rig’s site installation and drilling during the winter. Sound pressure levels (SPLs) generated by the Kolskaya were similar to previous measurements from the metal-legged bottom-founded rigs, both in level (120 dB re 1μPa) and in frequency range of dormant tonals (2-1400 Hz). Received levels were highly variable over short periods and generally varied by 15-20 dB between quietest (holding) and loudest (drilling) operations. The rig was significantly quieter than its associated support vessels at low frequencies, though radiated noise levels were higher above 2 kHz. The rig’s high-frequency SPLs dropped rapidly above 8 kHz.

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