They both exhibit self-similarity; when viewed at different scales they appear the same, so that the whole surface is made up of a number of smaller versions of itself as can be seen by this striking photo of Romanesco broccoli.
This property has important implications for measuring the roughness of a glacier's surface, which fjord has been helping Jon to do on Mitdre Lovénbreen. The roughness measured will depend on the scale of measurement; to an extent the larger the scale over which the roughness is measured, the rougher the surface will appear to be.
Fjord has been helping Jon make measurements using two methods, each at a different scale. The first method, at a scale of 15m, involves measuring the distance to the surface along the length of a fixed horizontal length of cord.
The second method measures at a smaller scale of 1 metre, and is much quicker. Here fjord pushes a black metal plate vertically down into the surface. A photo of the plate will show the outline of the glacier surface along the line of the plate, contrasted against the black plate. Using image processing software the photo can be turned into an accurate representation of the surface roughness. Fjord prefers this method as it is much quicker.
Roughness is an important surface characteristic because its affect on the flow of air over the glacier surface influences the amount of heat transferred between the ice and the atmosphere and also because it is seen as "texture" in aerial and satellite imagery.