  We study the cone of Moriwaki divisors on \bar{M}_g by means of augmented
base loci. Using a result of Moriwaki, we prove that an R-divisor D satisfies
the strict Moriwaki inequalities if and only if the augmented base locus of D
is contained in the boundary of \bar{M}_g. Then we draw some interesting
consequences on the Zariski decomposition of divisors on \bar{M}_g, on the
minimal model program of \bar{M}_g and on the log canonical models
\bar{M}_g(\alpha).
