2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/138138We refine results of Hwang, Keum and Szemberg, Tutaj-Gasinska which relate local invariants - Seshadri constants - of ample line bundles on surfaces to the global geometry - fibration structure. We show that the same picture emerges when looking at Seshadri constants measured at any finite subset of the given surface.8 pages, to appear in Math. NachrAlgebraic Geometry14C20, 14D06, 14E25text