Skildring:
Broadband echogram showing backscattering by a small natural seep of methane (red box) near Node 7 of the Lofoten Vesterålen Ocean Observatory. The broadband frequency response of the seep is also shown (lower right inset). The seep consists of a few small single bubbles rising from the seafloor at a depth of 220 meters, clearly observed in the broadband data.