Maar-Diatreme Volcano (image) University at Buffalo Caption Lunar Crater maar in Nevada, a maar-diatreme volcano. A new study is shedding light on the explosive mechanism of these volcanoes, which erupt just once before dying. Credit Credit: Greg Valentine Usage Restrictions This image may only be used with news reports discussing the associated research. 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.