appear black or purple, whereas vegetated areas appear as
shades of green. The fissures and irregular channels from the
1991–1992 eruption are buried by snow and ice in the
Landsat-7 image, and therefore the 1991–1992 lava flow
cannot be differentiated from its surroundings on the upper
flank of the volcano. In contrast, the distal end of the 1991–
1992 flow is easily distinguishable from the lava flows of
previous eruptions on the volcano’s lower flank (Fig. 1c).