Atmospheres of Oil & Gas: the Four Corners Methane Cloud and Contests Over Land in the San Juan Basin



Hotspot: A Signal from Space ///

Nestled between mountain ranges, the San Juan Basin is an oval shaped geological depression that spans approximately 6,500 square miles across large parts of northern New Mexico and the southwestern tip of Colorado. Long studied by geologists and archeologists, in recent years a group of atmospheric scientists have also been drawn to the San Juan Basin. What pulled these scientists to the Four Corners region of the U.S. southwest, where the states of Arizona, Colorado, New Mexico, and Utah neatly intersect, was an unusual signal detected by instruments aboard an international space satellite. The signal suggested that an especially large quantity of methane, a powerful greenhouse gas, was emitted from this region.

Grant Funambulist 2
Map of the San Juan Basin in northern New Mexico and southwestern Colorado, USA.

At first the researchers thought the signal might indicate a glitch in their sensing apparatus. But they soon got wind of data collected from another team of researchers at New Mexico’s Los Alamos National Laboratory (LANL), who had set up a ground-based air monitoring site in northern New Mexico near the San Juan Basin’s two mouth-to-mine coal plants. The LANL researchers were looking at other pollutants, but their instruments also measured methane in the atmospheric column. With the help of atmospheric models, the data gathered by the team at LANL could be used to help verify what the satellite had seen. Not only was a lot of methane coming from the San Juan Basin: the combined findings suggested that both national and international greenhouse gas inventories significantly underestimate how much is emitted from the region’s largest source of methane: oil & gas production.

The methane hotspot was plotted as a bright red dot on a map of the continental United States, making the Four Corners stand out amidst a sea of purples, blues, and greens — colors that denote more normal distributions of the gas. The image began circulating widely upon its release in late 2014, announcing the discovery of “the largest U.S. methane anomaly viewed from space.” News of the methane cloud hovering above the San Juan Basin has drawn significant attention to the region, including follow-up studies that have confirmed that the oil & gas sector is by far the biggest methane emitter in the basin. But more than a sensational story and a catalyst for animating nationwide conversations about the contribution of the oil & gas industry to the country’s greenhouse gas budget, the methane hotspot has served as a measured and measurable index of the cumulative impact of extraction in the region. It’s a sign that something in the air isn’t quite right.