This MATLAB code generates a video to simulate the Be-10 accumulation in arable soils
This model simulates the accumulation of Be-10 under a surface that is being eroded at a constant rate of 50 mm/ka:
- from t=0 to 50 ka, the density of the profile is constant
- from t=50 to 100 ka, the density of the profile changes to simulate soil in the upper 1.5m and saprolite until a depth of 3m. The profile is still in equilibrium: the soil production rate (SPR) is the same as the erosion rate at the top of the profile (both 50 mm/ka)
- from t=100 to 150 ka, the top 20 cm of the profile is affected by bioturbation, generating a mixing layer enriched in Be-10
- from t=150 to 200 ka, sustainable agriculture is simulated by a mixing layer of 50 cm
- from t=200 to 201 ka (last 1000 years), unsustainable agriculture is simulated by eroding the surface at a rate faster than the soil production rate (the profile is not in equilibrium!)
The effect of unsustainable agriculture is like a bulldozer that removes the top of the soil and mixes the first 0.5 m of the remaining soil.
At the end of the simulation, I have calculated the apparent soil production rate (a-SPR) from a sample taken in the saprolite (red star).
The a-SPR is faster than the actual SPR (110 mm/ka vs. 50 mm/ka), but much slower than the erosion rate generated by unsustainable agriculture (~3000 mm/ka).
Also, a red line illustrates the Be-10 profile we would reconstruct from that sample usign CoSOILcal, which matches well the actual Be-10 profile. This means that even taking several samples from this profile, we probably wouldn't notice the break in the equilibrium generated by unsustainable agriculture.
The script generates this video:
There is a post illusrated by this model in my blog.
Feel free to use this code. You can cite the CoSOILcal paper as a reference for academic publications.