Methane hydrates are a naturally-occurring ice-like substance
found in permafrost and in ocean sediments along continental
shelves. Hydrates are sometimes the source of cold seeps—plumes
which release methane gas into the marine environments, which
may subsequently release the gas into the atmosphere. Methane
hydrates and methane gas seeps are of particular interest both
for their potential as an energy source and for their possible
contribution to climate change. In an effort to improve location
of hydrates using seismic surveys and echo-sounding technology,
this research aims to describe the low-frequency (10 Hz to 10
kHz) acoustic behavior of hydrates in their solid and gas phases
in natural and simulated marine environments. Work includes, but
is not limited to, laboratory experiments on pressurized bubbly
liquids, measurements of natural methane hydrate (structures I
and II) sound speeds as a function of pressure, passive sensing
of gas seeps, and finite element modeling and analysis of
sediments and mar