The volcano boasts an ice cap on its summit, and radar imaging of the rock beneath the ice has shown that the mountain's flat-topped summit is not just attributable to the ice cap, but the top of the mountain is flat as well. Beneath the summit ice cap lies an ice-filled volcanic crater that rises at an elevation of and a topographic prominence of . Except for minor irregularities caused by erosion, any contour line drawn is practically a circle.