Penitentes (IMAGE) University of Colorado at Boulder Caption University of Colorado Boulder student Lara Vimercati examines a nieves penitente structure on Volcán Llullaillaco in Chile. Credit Steve Schmidt / University of Colorado Boulder Usage Restrictions None 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.