crevice

A crevice is a narrow opening or fissure in rock or other solid material. It typically forms as rocks are stressed, weathered, or dissolved, and can occur at natural joints, faults, or along surfaces where differential erosion has occurred.

In geology, crevices develop wherever joints or fractures are widened by processes such as freeze-thaw cycling, thermal expansion, and chemical weathering. Water and root growth can further widen and propagate crevices, creating pathways for infiltration and localized erosion. Crevices are often irregular in shape and can vary in depth from a few millimeters to several meters.

In ice and glaciers, the term crevasse is often used for deep cracks that form as ice flows over uneven terrain or experiences internal stress. Although the terms crevice and crevasse are sometimes used interchangeably in casual language, crevasse is standard in glaciology.

Ecologically, crevices provide microhabitats and shelter for lichens, mosses, invertebrates, and small vertebrates. They can collect water and concentrate nutrients, supporting localized communities and affecting rock weathering.

For humans, crevices can be hazards in climbing and mining, and crevices in masonry or concrete can permit water ingress and promote deterioration if not properly sealed or repaired.