noun / verb
fissure
FISH-er/ˈfɪʃər/
A narrow split breaking the continuity of a surface.
A long, jagged fissure runs through the pale slab of rock.

Etymology
Here splitting is viewed through its result: a cleft or opening, rather than the action itself. The English word preserves that image in its sense of a long, narrow crack.
In context
they express some concerns about this fissure here you can see the two stems have started to split
More examples
- Water seeps into small fissures in the concrete.
- The dry clay begins to fissure along its edges.
- The inspector finds a hairline fissure in the pipe.
Forms
fissure · fissures · fissured · fissuring