Linda Morobito discovered the existence of one of these features after observing an anomalous “crescent” photographed by Voyager 1. The CIRS experiment’s observation of “tiger stripes” provided evidence of one (15[2])form of (15[1])these features on Enceladus. Orbital resonance forces the (15[1])eccentricity of the orbit of Io, (10[1])resulting in (*) tidal forces (10[1])which cause (10[1]-5[1])these (10[1])features to (-5[1])form. Christopher G. Newhall and Stephen Self developed the VEI, which separates these features into classes like Plinian and Strombolian based on their tephra. (10[1])On earth, some of these features expel mafic material in flows called ʻaʻā (10[1])(“AH-ah”) or pāhoehoe (“pa-HOW-ay-how-ay”). For 10 points, calderas and cinder cones are examples of what features which can violently (10[1])erupt (10[1])to release lava? ■END■