Since then the glaciers have retreated further because of atmospheric warming. By 1959, the massif's glaciated area had dropped to . Since the 1985 eruption, which destroyed about 10% of the summit ice cover, the area of Nevado del Ruiz covered by glaciers has halved—from just after the eruption to about in 2003. The glaciers reached altitudes as low as in 1985 but have now retreated to elevations of .