The measurement of the underwater radiated noise from marine piling including characterisation of a "soft start" period

Underwater radiated noise is often an unintended by-product of offshore activities, and the increasing levels of man-made sounds in the ocean (whether deliberately generated or not) have led to concern over marine noise pollution and its effect on marine life. A significant source of impulsive underwater noise is marine piling where a pile is driven into the sea-bed using a hydraulic hammer. Such a technique is typically used to position piles in relatively shallow water for construction of offshore windfarms, bridge supports, and offshore structures associated with the off and gas industry. To mitigate the effects of the noise generated, the piling sequence is often begun with a gradually increasing energy level, this procedure being termed a "soft start".