Sailing for science

Physical property specialists Philip Long (PNNL) and Anne Tréhu (Oregon State University) operate an infrared camera on the catwalk of the JOIDES Resolution. The infrared camera helps the scientists identify which portions of the core contain gas hydrate.

When most people think of an ocean cruise, they think of buffets and relaxing in deck chairs. For Pacific Northwest National Laboratory researcher Philip Long, an expedition cruise aboard the Joint Oceanography Institutes Deep Earth Sampling (JOIDES) Resolution research vessel meant 12-hour workdays examining ocean floor core samples for methane hydrate.

Methane hydrate is an ice-like substance made of water and methane (natural gas) that occurs beneath ocean floors. It looks like ice, but it burns when ignited. A single liter of methane hydrate equals the energy of 164 liters of natural gas, by volume. This fact, coupled with estimates of the abundance of methane hydrate worldwide, has piqued interest in its potential as a fuel source. However, these ice pockets in the ocean sediment melt quickly when brought to the surface and release methane into the atmosphere.

Researchers are investigating the role that these deposits have played in ancient global climate change and the possible effects on future climate change. The icy hydrates serve to cement the ocean floor sediments, stabilizing the sea bottom. If the methane hydrates melt due to a warming climate, destabilized sediments could shift in undersea landslides.

The National Science Foundation and the Department of Energy Office of Fossil Energy sponsored two hydrate expeditions for the JOIDES Resolution— one along the Oregon Coast and the other off Vancouver Island. Long’s role on the scientific team for both expeditions was to scan core samples for hydrates using infrared thermal imaging.

Long and fellow PNNL scientist H. Todd Schaef embarked on another expedition last summer to locate deposits of hydrates in the Indian Ocean and Andaman Islands. The Indian government sponsored the expedition to study possibilities of retrieving and storing methane gas to offset its demand for new sources of energy.