ASPECT: surface processes and basin formation through a two-way coupling with FastScape

A snapshot of an evolving asymmetric rift model at 12 Myr. The FastScape surface is colored by topography, and additionally shows the drainage area (blue to white) and erosion rate (white to black). [cont]

The FastScape-ASPECT coupling is a two-way coupling that allows the landscape evolution model FastScape to deform the surface of ASPECT. Geodynamic models commonly simulate surface motions by using either a free surface or a sticky air layer. Either method can produce unrealistic highs or lows in the topography because they do not account for erosional and depositional processes that redistribute surface material through time. This redistribution not only helps obtain realistic topographies, but the change in surface loading can have widespread effects on model evolution, such as lengthening the time a fault remains active (Olive et al., 2014), promoting model asymmetry and rift migration, or altering the thermal state through sediment blanketing.

FastScape is an open-source code available in multiple languages (Fortran, C++, and Python; Braun and Willett, 2013) that deforms a surface through routines that mimic geomorphic processes. This is primarily done using three methods: 1) hillslope diffusion, 2) the Stream Power Law (SPL), and 3) marine transport. On the continents, hillslope diffusion will move ... [continued]