DC Gasleak Barmap (image) Duke University Caption This is a satellite image of the District of Colombia with bar charts showing where natural gas leaks were located under city streets and in what concentration methane was identified. Higher bars indicate higher concentrations in parts per million. Credit Duke University Usage Restrictions Please credit Duke University. 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.