We give the classification of normal del Pezzo surfaces of rank one with at most log
canonical singularities containing the affine plane defined over an algebraically nonclosed
field of characteristic zero. As an application, we have a criterion for del Pezzo fibrations
with canonical singularities whose generic fibers are not smooth to contain vertical
-cylinders.
Keywords
normal del Pezzo surface, compactification of the affine
plane, algebraically nonclosed field