Ogive (glacier)

An ogive is a geographic feature of certain types of glaciers. They are identified as light and dark bands of ridges and valleys found at the base of glacial icefalls. They are usually found on 'advancing' or 'neutral' glaciers.

Ogives are created by icefalls. The icefalls produce a pattern of alternating ridges and swales that gradually flatten out downglacier. They also bend throughout the glacier, because the velocity of the glacier is greater near the center.

As ice passes through an icefall it is usually very broken-up, which greatly increases the ablation surface area in the summer, and provides space for enhanced entrapment of snowfall during the winter. Winter ice that passes through the icefall becomes bulgy, irregular and hummocky at the base of the icefall, while summer ice turns into a swale.

References

• Easterbrook, D.J. (1999) Surface processes and landforms. (Second Edition). Prentice Hall, Upper Saddle River, New Jersey.