This is the list of changes made after the release of ASPECT version 3.1.0. All entries are signed with the names of the author.

1. Improved: Local Smoothing GMG with mesh deformation now applies the correct tangential boundary conditions on multigrid levels and reuses its transfer operator for the mesh displacement solve and level updates, changing iteration counts slightly.
   (Timo Heister, 2026/10/07)

2. Fixed: Global coarsening GMG now supports prescribed velocity boundary conditions with component masks.
   (Timo Heister, 2026/10/08)

3. Fixed: Global coarsening GMG no longer evaluates the simulator's MappingQCache on separate hierarchy triangulations, avoiding crashes for curved geometries.
   (Timo Heister, 2026/10/07)

4. Changed: The coarse-grid Schur complement solve in the matrix-free GMG now uses manually chosen eigenvalue estimates instead of trying to determine them at runtime, which can often fail and produce unphysical solutions in coarse computations. As a result, this change potentially improves solver convergence.
   (Timo Heister, 2026/10/05)

5. Updated: Composition reactions (operator splitting on fields) are no longer automatically computed for all fields; fields tracked by particles are excluded. This enables the simultaneous use of operator splitting for fields tracked by fields and particle updates for fields tracked by particles.
   (Anne Glerum, 2026/09/27)

6. New: Local-smoothing GMG supports 2D periodic spherical shells with 90- and 180-degree opening angles, using deal.II 9.9 or greater. Adaptive refinement and coarsening keep periodic partners at matching levels.
   (Francesco Radica, 2026/09/23)

7. Fixed: Stokes matrices and preconditioners are now rebuilt when the pressure scaling factor changes during a simulation.
   (Timo Heister, 2026/09/22)

8. Changed: The –validate command now initializes the simulation, including creating plugins, the mesh, and solvers, and performs consistency checks before exiting. It still stops before the first time step is taken.
   (Timo Heister, 2026/09/22)

9. Added: A function to landlab.cc that enables additional quantities to be sent to Landlab from ASPECT. The strain rate on the surface of the ASPECT model can now be provided.
   (Daniel Douglas, 2026/09/16)

10. New: Mesh deformation can now be used with the global-coarsening matrix-free Stokes solver (GMG-GC), including geometries with periodic boundaries.
    (Timo Heister, 2026/09/07)