We explore the controls on erosion via lava flow to the edifice of Momotombo volcano, Nicaragua. A remarkable feature of the channel, thought to be constructed by the 1904 lava flow, is that it is down-cut into the conical edifice of the volcano, rather than simply constrained by levees on its margins. We consider the possibility that the channel was formed during the 1904 eruption by thermal and / or mechanical erosion. Preliminary results suggest thermally sourced down-cutting to be an unlikely contributor due to the low temperature of erupted lavas ( < 1050 ºC) and a high temperature differential between the erupted lava and the pre-existing edifice. Mechanical factors, therefore, provide a more probable source of erosive energy. We aim to quantify the energy required to create the observed topography by merging existing field observations, a time series of digital elevation models that straddle the 2015-2016 eruption, and mathematical models of mechanical erosion via lava flow.