Detrital in situ and meteoric Beryllium 10 measurements from samples taken before and after Hurricane Maria in Dominica

To test whether such storms bias isotopic indicators of long-term erosion, we measured 10Be in samples collected before and after Hurricane Maria (2017, category five) from Dominica, an andesitic island in the Caribbean. Populations of before- and after-storm concentrations of 10Be are indistinguishable (n = 7 for in situ, n = 11 for meteoric); however, individual sample sites replicate less well with isotopic concentrations in samples taken before and after the storm varying by an average of 12%.

These data suggest that processes controlling the depth and amount of near-surface erosion on Dominica during extreme storms are stochastic. Erosion rates determined from in situ 10Be are low compared to similarly steep and wet areas (median = 0.082 mm/yr, n = 12) and appear to be controlled by orographic precipitation.