[CIG-MC] ASPECT 1.3 released

[Timo Heister]

We are pleased to announce the release of ASPECT 1.3. ASPECT is the Advanced
Solver for Problems in Earth's ConvecTion. It uses modern numerical methods such
as adaptive mesh refinement, multigrid, and a modular software design to
provide a fast, flexible, and extensible mantle convection solver. ASPECT is
available from

                        https://aspect.dealii.org/

This release includes the following changes:
- New: Averaging of material properties between the quadrature points of a
  cell. This greatly increases the stability of solutions in simulations with
  spatially varying coefficients, and also greatly accelerates the solution,
  at times up to a factor of ten.
- Corrections to the entropy stabilization scheme for compositional fields.
- Fixed and extended: Removal of rigid body translations and rotations when
  the simulation has a nullspace.
- New: VTU visualization output can now be grouped into an arbitrary number of
  files per time step.
- Various fixes to the nonlinear solver residual computation.
- New visualization postprocessors that can output the shear stress and full
  stress tensors.
- Fixes to the latent heat formulation.
- New 'ascii data' plugins for boundary and initial conditions.
- New mass flux statistics postprocessor.
- Many other fixes and small improvements.

A complete list of changes can be found at
  https://aspect.dealii.org/doc/doxygen/changes_between_1_82_and_1_83.html
and the release is also available from
  https://github.com/geodynamics/aspect/releases/tag/v1.3

Wolfgang Bangerth, Timo Heister, and many other contributors.


-- 
Timo Heister
http://www.math.clemson.edu/~heister/