  During early phases of a protoplanetary disks's life, gravitational
instabilities can produce significant mass transport, can dramatically alter
disk structure, can mix and shock-process gas and solids, and may be
instrumental in planet formation. We present a 3D grid-based radiative
hydrodynamics study with varied resolutions of a 0.07 M$_\odot$ disk orbiting a
0.5 M$_\odot$ star as it settles over most of its radial extent into a
quasi-steady asymptotic state that maintains approximate balance between
heating produced by GIs and radiative cooling governed by realistic dust
opacities. We assess disk stability criteria, thermodynamic properties,
strengths of GIs, characteristics of density waves and torques produced by GIs,
radial mass transport arising from these torques, and the level to which
transport can be represented as local or nonlocal processes. Physical and
thermal processes display distinct differences between inner optically thick
and outer optically thin regions of the disk. In the inner region,
gravitational torques are dominated by low-order Fourier components of the
azimuthal mass distribution. These torques are strongly variable on the local
dynamical time and are subject to rapid flaring presumably driven by recurrent
swing amplification. In the outer region, m=1 torques dominate. Ring-like
structures exhibiting strong noncircular motions, and vortices develop near the
inner edge between 8 and 14 au. We find that GI-induced spiral modes erupt in a
chaotic manner over the whole low-Q part of the disk, with many spiral modes
appearing and disappearing, producing gravitoturbulence, but dominated by
fluctuating large-scale modes, very different from a simple $\alpha$-disk.
