Understanding Physical Properties of Gas Bubbles in the Ocean: How Does Reality Affect What We Think We Already Know?

Alexandra Padilla
Ph.D. Proposal Defense

Ocean Engineering

Monday, Dec. 14, 2020, 2:00pm

Methane is a greenhouse gas that contributes to global warming. The increase in atmospheric methane has led researchers to study the various sinks and sources, one of which is the source of methane from the seafloor. Methane is released from the seafloor as both dissolved fluids and gas bubbles. Methane gas bubbles, however, facilitate the rapid transport of methane through the ocean, altering the water column’s geochemistry as bubbles rise. Methane gas bubbles, under certain conditions, can reach the upper water column and potentially contribute methane to the atmosphere. Researchers are interested in improving current techniques used to study and quantify the contribution of seafloor methane to the global atmospheric methane budget.

Methane gas bubbles released from the seafloor are often studied with a combination of in-situ instruments (e.g., optical systems), numerical transport models, and acoustic systems. This allows the study of the fate and transport of methane through the water column and, potentially the atmosphere. These models, however, are derived under assumptions that are not always valid for the study of methane gas bubbles in the ocean. This thesis, therefore, aims to understand and quantify how variations in gas bubble properties (e.g., non-sphericity, surface coatings, external physical processes, etc.) impact current techniques used to observe and quantify the fate of methane gas bubbles rising through the water column.


Alexandra graduated from the University of Puerto Rico – Mayaguez with a B.S. in Mechanical Engineering and a minor in Applied Mathematics. As an undergrad, she began research in the area of Material Science and Engineering but soon realized that she had an interest in Ocean Engineering, specifically underwater acoustics. Currently, she is pursuing a Ph.D in Ocean Engineering and her research revolves around acoustics and bubbles.