Oil and Gas Map (IMAGE) Penn State Caption A map of coal mines and unconventional natural gas wells, both potential sources of methane emissions. The green square contains the area in which the flights took place to measure methane from these sources. Credit Zachary Barcley, Penn State Usage Restrictions Non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.