The Earth surface evolves under the action of geological, chemical, physical, biological and anthropogenic processes involving a wide range of time and length scales (from the meter and the second up to the thousand of kilometers and the million years). These processes control the evolution of soils, the shape of landscapes and the coupling between climate, tectonics and erosion. Understanding them requires to monitor experimental catchments over durations long enough to capture all the time scales involved. The Observatory of Erosion in the Antilles (ObsERA) was created in 2011 by the CNRS-INSU to address these problematics. Its objectives are : (1) to investigate chemical and physical erosion, their feedbacks and their influence on the carbon and water cycles and the environment (soil development, rivers chemistry, etc. .. .) in the peculiar context of a tropical volcanic island, (2) to promote the development of new instruments and methods (including new isotopic tracers) for monitoring sediment transport by rivers and slope processes and characterizing the ecosystem dynamics; (3) to investigate how extreme events (floods induced by heavy rains and tropical storms, earthquakes, …) influence geochemical cycles (e.g. carbon cycle), denudation rates and landscape morphology.
In this aim, ObsERA monitors the evolution of environmental variables (e.g. rainfalls, river discharge, conductivity, suspended load, chemical composition of soils, rivers and precipitations, …) in 3 catchments located on Basse-Terre Island, a volcanic island of the Guadeloupe archipelago (Lesser Antilles arc). ObsERA also monitors the granulometry and the morphology of several river reaches using drone-acquired aerial images and a terrestrial lidar. These data are made freely available to the scientific community on the following web site https://morpho.ipgp.fr/Obsera.