Geomorphological information mapping of debris-covered ice landforms using Google Earth: An example from the Pico de Posets, Spanish Pyrenees

Abstract

Geomorphological mapping records ‘snapshots’, making it difficult to investigate change and sensitivity in changing environments. The high resolution now available in Google Earth (GE) permits re-investigation of landscape features/landforms previously recorded in the literature or mapped. Transects across geomorphologically interesting locations can be provided with decimal degree WGS 84 locations and bearings via GE. Landform elements are identified, located and coded onto transects that summarise geomorphological information. Transects crossing rock cliffs, scree slopes, snowpatches, protalus ramparts, ‘vanishing’ glaciers, moraines and rock glaciers are investigated using GE on the Pico de Posets in the Spanish Pyrenees. Observations of geometry/form, materials and processes involved in ice and sediment movement are linked to the Randolph Glacier Inventory and map records. The transect mapping shows that accumulated weathered rock debris insulated a remnant Little Ice Age glacier that formed a lateral moraine and a contiguous rock glacier as the glacier wasted down. Landforms previously considered to indicate permafrost are shown not to do so. Glacigenic formation of moraines, protalus rampart and rock glaciers provides the simplest explanation for their origin.