From phantom blocks to denudational noise : downwearing of the Himalaya Tibet orogen from a multi scale perspective Knowing the rates and mechanisms of geomorphic process that shape the Earth’s surface is crucial to understand landscape evolution. Modern methods for estimating denudation rates enable us to quantitatively express and compare processes of landscape downwearing that can be traced through time and space—from the seemingly intact though intensely shattered phantom blocks of the catastrophically fragmented basal facies of giant rockslides up to denudational noise in orogen wide data sets averaging over several millennia. This great variety of spatiotemporal scales of denudation rates is both boon and bane of geomorphic process rates. Indeed processes of landscape downwearing can be traced far back in time helping us to understand the Earth’s evolution. Yet this benefit may turn into a drawback due to scaling issues if these rates are to be compared across different observation timescales.This thesis investigates the mechanisms patterns and rates of landscape downwearing across the Himalaya Tibet orogen. Accounting for the spatio…