pub fn micrometeorite_overturn_rate_mm_myr(flux_index: f64) -> f64 {
    0.7 + 1.8 * flux_index.max(0.0)
}

pub fn space_weathering_index(exposure_myr: f64, solar_wind_factor: f64) -> f64 {
    (1.0 - (-exposure_myr / 130.0).exp()) * solar_wind_factor.max(0.0)
}

pub fn viscous_relaxation_rate_mm_yr(slope_deg: f64, ice_fraction: f64) -> f64 {
    slope_deg.max(0.0) * 0.020 + ice_fraction.clamp(0.0, 1.0) * 1.0
}
