Methane Bubbles Frozen in an Alaskan Marsh

January 25, 2021


Photographer: Gabrielle Tepp 
Summary Author: Gabrielle Tepp 

Before the winter snow starts falling, a frozen marsh or lake can be a beautiful sight. Bacteria living off the organic matter at the bottom of the marsh releases methane gas, which creates white bubbles when frozen in ice, as shown above. How the bubbles appear in the frozen ice is dependent on the rate of the gas release and also the rate at which the ice forms. If the gas release is relatively slow, the bubbles will freeze in a vertical stream with layers of ice in between bubbles, as in the center photo. If the gas is released faster than the ice freezes, the gas bubbles build up and grow into larger bubbles or more complex patterns, as seen in the right photo. The frozen bubble streams can also capture a snapshot of just how the water was flowing as the ice was expanding. I enjoy skating or walking around the marsh to see how the bubbles differ in each pond. Photos taken on November 3, 2020, at Potter Marsh in Alaska.