Bubbling From Melting Glaciers Makes Fjords Noisiest Places in Oceans

Bubbles gushing from melting glaciers and their icebergs make fjords the noisiest places in the oceans, according to research published in Geophysical Research Letters. Researchers used underwater microphones to record noise levels in three bays where glaciers flow into ocean fjords and icebergs calve from glaciers. They found that average noise levels from bubbles in these fjords exceeded those generated by all other sources, including weather, wildlife, and machines such as ships and sonar devices. Glacial calving contributed some of the noise, but the constant melting and bubbling was the real culprit, the researchers said. Their findings raise questions about how the underwater noise in the fjords — which are foraging hotspots for seabirds and marine mammals and important breeding habitat for harbor seals — will affect animals as climate change further increases melting rates.