A stepwise screening system to select storm-sensitive stalagmites: Taking a targeted approach to speleothem sampling methodology

摘要

A stepwise stalagmite sample screening process was applied in order to select a stalagmite as a sensitive recorder of recent tropical cyclone rainfall events near Belize. Field and laboratory criteria were combined in series, to screen out candidate stalagmites whose characteristics indicated lower sensitivity to stormwater infiltration. The approach described here was designed to increase the likelihood that selected stalagmites would increase the signal:noise ratio of the target phenomenon in the resulting proxy records. This four-stage method for sample selection may be an important methodological consideration for researchers attempting to use speleothems for stable isotope paleotempestology. Hallmarks of this approach include: (1) establishing a priori scientific targets, (2) applying sample criteria in the form of contra-indicators, and (3) organizing the sample screening protocol into a series of practical stages. The overall approach to stalagmite selection presented here supports cave conservation, and can be adapted readily by others in support of different scientific goals. It is hoped that other investigators will also publish field and laboratory sample selection schemes, as increased transparency will provide new information invaluable to replication efforts and to advancing the field of speleothem paleo-environmental studies.