Topographic signature of tectonics in glacial landscapes

An interplay of rock uplift and glacial erosion shapes glacierized mountains across the globe. Under the simplifying assumption that subglacial bedrock erosion is proportional to the local ice flux, a steady balance between uplift and erosion is used to theoretically predict the elevation distribution (hypsometry) of glacier cover above the long-term snowline. When snow accumulation rates increase linearly with elevation, the theory predicts a half-normal distribution with a range that is proportional to the million-year scale local uplift rate. The theoretical form fits well the present-day hypsometry of glacier cover in glacierized mountain ranges across the globe, which may indicate a prevailing approximate long-term balance between glacial erosion and uplift. The fits obtain realistic estimates of the spatial patterns of uplift, which align well with geologic boundaries, and explain global variations in the maximum height of mountain peaks measured from the long-term local snowline. However, a comparison of hypsometry-derived uplift rates with thermochronology-derived exhumation rates yields large residuals, likely due to the simplifying assumptions and a poorly calibrated erosion law. Despite the limitations, the steady-state theory presented successfully describes both the glacier-cover hypsometry and the peak heights on a global scale, connecting them to the million-year scale local uplift rates.