Fig. 187—Glacial topography between Lambrama and Antabamba in the Central Ranges. A recent fall of snow covers the foreground. The glaciers are now almost extinct and their action is confined to the deepening and steepening of the cirques at the valley heads.
Fig. 188—Asymmetrical peaks in the Central Ranges between Antabamba and Lambrama. The snow-filled hollows in the photograph face away from the sun—that is, south—and have retained snow since the glacial epoch; while the northern slopes are snow-free. There is no true glacial ice and the continued cirque recession is due to nivation.
Fig. 189—Glacial topography north of the divide on the seventy-third meridian. Maritime Cordillera. Looking downstream at an elevation of 16,500 feet (5,030 m.).
Furthermore, the leeward side of a lofty mountain not only receives much less snow proportionally than the leeward side of a lower mountain, but also loses it faster on account of the smaller extent of surface upon which it is disposed and the proportionally larger extent of counteractive, snow-free surface about it. Among the volcanoes of Ecuador are many that show differences of 500 feet in snowline elevation on windward and leeward (east) slopes and some, as for example Chimborazo, that exhibit differences of 1,000 feet. The latter figure also expresses the differences in the broad Cordillera Vilcapampa and in the Maritime Cordillera, though the rate of canting as expressed in degrees is much greater in the case of the western mountains.