| Conversely, an unusually light winter snowfall causes older firn and ice of lower albedo to be exposed earlier in the summer, producing increased melt and runoff. |
| Melt and percolation through the weak firn layer bring most of the freeboard volume to the melting point. |
| In temperate glaciers, snow repeatedly freezes and thaws, changing into granular ice called firn. |
| River of ice formed by the flow of the firn. |
| Combine such dense firn with a daily rhythm of freeze and thaw, and spring avalanche danger is easy to predict and avoid. |
| Situated high on a mountainside near the firn line, they are typically partially surrounded on three sides by steep cliffs. |
