Study of climatic variability in the Caribbean from speleothems taken from two caves in Cuba

David Noncent Université Quisqueya, Ecole doctorale "Société et Environnement" 218 avenue Jean Paul II, Port-au-Prince, Haïti

1. Introduction Variability and climate change have long ceased to be a scientific curiosity. They are the major environmental issue that dominates our times and the major challenge facing environmental regulators. On millennial timescales, Caribbean climate anomalies have been suggested to be in phase with climate change in Europe (Haug et al., 2001; Hillesheim et al., 2005). Climate change in the Caribbean area has played an important role in local human history. For instance, episodes of severe drought on the Yucatan peninsula are thought to have caused the collapse of the Maya civilization (Hodell et al., 1995; Haug et al., 2003). It is, therefore, important to investigate the processes controlling climate variability in the Caribbean (Jury et al., 2007). Speleothems are of increasing interest to climatologists because of their high potential as paleoclimatic records. Most often studied for their isotopic recordings of oxygen and carbon, they nonetheless offer many other vectors of paleo-environmental information at different scales and resolutions (Couchoud, 2008). The objective of this work is to present a post-review on the variability of the climate from a high-resolution oxygen isotope records from two stalagmites from north-western Cuba, which provide proxy data for past precipitation changes covering most of the last 12 000 years.

2. Methods The analyzes were performed on two stalagmites (CP: Cuba Pequeo, CM: Cuba Medio) taken from two caves in Cuba (Dos Anas and Santo Tomas cave system). Stable isotopes (oxygen and carbon) were sampled and analyzed at Innsbruck University at a resolution of 0.2 mm for CP corresponding to a temporal resolution of 4-10 a. The resolution for CM is 0.1 mm corresponding to a temporal resolution of 15 a.

3. Results and discussion The article is of great interest, it presents a range of knowledge on climate variability. Comparisons of climate variability between different regions were made. Stalagmite δ18O values of Cuba stalagmites were compared with the percentage of hematite-stained grains (HSG) in subpolar North Atlantic deep-sea sediments, which record the Bond events (Bond et al., 1997, 2001). Stalagmite δ18O values of Cuba stalagmites were also compared with two SST records off West Africa (deMenocal et al., 2000). The δ18O record of stalagmite from Cuba reflects precipitation variability in the Caribbean during the last 12.5 ka. The stalagmite record shows the same trend as a marine surface water δ18O record off Haiti (Horn, 2011) suggesting that, on orbital timescales, the δ18O value of precipitation mainly reflects the δ18O value of the source of the water vapor (i.e., the North Atlantic and the Caribbean Sea).

4. Conclusion The aim of this work is to present a post-review on climate variability from high-resolution oxygen isotope records from two stalagmites from north-western Cuba. We notice that on millennial timescales, the Cuban record exhibits a good agreement with an SST record off West Africa and the Bond events, which indicates a connection to North Atlantic SSTs.

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