Gabrielle Pétron, a climate scientist from the University of Colorado Boulder, takes a moment to point out exposed shale outcroppings at Carbon Junction. These outcroppings are a known source of methane emissions in the Four Corners region./Photo by Jeremy Wade Shockley

The hot spot

Researchers crisscross region tracking sources of methane

by Jeremy Wade Shockley   

 

The large gray van pulled into the small gravel parking lot at Carbon Junction, off Highway 3. Bearing almost no exterior markings, the NOAA (National Oceanic and Atmospheric Administration) mobile laboratory was clearly recognizable by a large boom mounted to the top of the vehicle and reaching over the front.

This arm houses sensitive air-monitoring equipment, which collects air samples in the field, and more specifically – the monitoring of methane activity in real time.

“The mobile lab is such an invaluable tool for talking about climate change,” Eryka Thorley, a climate scientist from the University of Colorado, Boulder, working in NOAA’s Earth System Research Laboratory, said.

Within a few minutes of turning off the vehicle’s engine, built-in monitors were streaming real time readings on air quality at a rate of once every two seconds. The source of methane was close at hand, and the readings were strong and consistent. The data pointed to a significant band of exposed coal  along the ridgeline adjacent to the Animas River, known as the “Fruitland Outcrop.”

Gabrielle Pétron, a climate expert from the UniversityColorado, Boulder who is also working in NOAA’s Earth System Research lab, led us on a short hike up the arroyo, where the shale beneath our feet gave way to dark, rich coal outcroppings. Pétron explained that depending on the geological layering of these coal seams, varying amounts of methane will either be emitted into the atmosphere or remain trapped under the Earth’s surface.

The prevalent readings are clear evidence that natural sources are playing a key role in regional methane levels, which have caught national attention in recent years. Yet natural sources alone cannot account for the San Juan Basin’s “methane hotspot” most recently garnering national headlines.

NOAA’s mobile lab checks area methane levels along a rural road near Bayfield./ Photo by Jeremy Wade Shockley

Pétron produced a laptop that showed us a computer rendering of the San Juan Basin, a large swath of land extending across the Four Corners. The rendering showed basic topography and a few key landmarks. With the click of a button, the map was overlaid with pin heads, each one representing active well sites across the Four Corners, each one potentially adding to the regional methane levels. The map was covered.

Pétron added that, in addition to the inventory of active oil and natural gas wells, there are an almost equal number listed as inactive, which also could potentially contribute to the high methane levels.

“The scale of it is really impressive,” Eric Kort, a climate expert with the University of Michigan, said. “This is a really productive basin.” 

The ultimate goal of the regional air quality study, known as The San Juan Field Campaign (spring 2015), is to collect as much data as possible in order to pinpoint individual sources and see where the methane levels are most prevalent. But this is proving easier said than done.

“It’s tricky to really pull it all apart,” Kort said.

For example, while scientists might detect a strong methane signal in a specific area, they must use data gathered in the field to determine the actual source of the methane. Then, they must identify whether the source is naturally occurring, a result of industry or agriculture – or a combination.

To make things more complicated, methane readings in the region could be, in part, from somewhere else, carried on the winds and ultimately settling here due to the topography.

Driving northeast out of town, the NOAA lab was soon taking air samples on rural county roads along Texas Creek. Methane levels clearly spiked as the team rolled past some of the natural gas wells located along the rural route.

While Pétron and Thorley collect air samples from the ground, teams systematically collect samples by aircraft, basing their operations out of the Durango-La Plata County Airport.

The researchers said the study has gained a sustained interest from the local community, as well as the Southern Ute Tribe, which has helped in data gathering.

“It’s obvious (the tribe) really cares about air quality and what they can do about (improving) it,” Thorley said. “We are all trying to work together to get the best picture.”

This story first appeared in the Southern Ute Drum on May 15, 2015.