An ice cap is an ice

Ice

Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 mass that covers less than 50 000 km² of land area (usually covering a highland area). Masses of ice covering more than 50 000 km² are termed an ice sheet

Ice sheet

An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

.

Ice caps are not constrained by topographical features (i.e., they will lie over the top of mountains) but their dome is usually centred on the highest point of a massif

Massif

In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole...

. Ice flows away from this high point (the ice divide

Ice divide

An ice divide is the boundary on an ice sheet, ice cap or glacier separating opposing flow directions of ice, analogous to a water divide. Such ice divides are important for geochronology investigations using ice cores, because such coring is typically made on top of a dome of an ice sheet to avoid...

) towards the ice cap's periphery.

Ice caps have significant effects on the geomorphology

Geomorphology

Geomorphology is the scientific study of landforms and the processes that shape them...

 of the area they occupy.