Two centuries of climate change from δ18O, δ13C and Sr/Ca analyses of a Cuban Coral
Abstract
Healthy Cuban coral reefs have remained resilient in the face of global change, shielded by a relatively underdeveloped coastline, a lower overall anthropogenic footprint, and strong environmental protection. Understanding long-term patterns of change in Caribbean climate parameters (e.g., SST and salinity) is of prime importance for assessing current and potential impacts of climate change on coral reef ecosystems in the region. Due to limited instrumental data, the largest Caribbean island, Cuba, lacks a continuous record of SST or salinity, resulting in incomplete knowledge of multi-decadal climatic sensitivity. Coral geochemical records, including stable isotopic compositions and elemental ratios, can provide high-resolution records of past climatic conditions and variability over timescales ranging from inter-annual to centennial. Cuba's extensive shallow platforms experience strong gradients of salinity, temperature and water density. We present the first continuous reconstruction of climate parameters from a 200+ year coral core collected in February 2015 from a Siderastrea siderea colony in the Golfo de Ana Maria, on the Southern Cuban coast. We obtained continuous, high resolution Sr/Ca measurements throughout the core by using Laser Ablation and Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). We also obtained detailed δ18O and δ13C measurements from ~20 years at both the top and bottom of the core, using Elemental Analyzer Isotope Ratio Mass Spectrometry. We cross-calibrated the two methods to provide a novel centennial-scale, high resolution, SST reconstruction for this region that highlights variations in absolute values and amplitudes of fluctuations through time, including significant anthropogenic signatures over the course of the two centuries, such as changes in the atmospheric carbon reservoir (the "Suess effect"). Caribbean SST records enhance understanding of mechanisms governing regional changes, such as the Atlantic Multi Decadal Oscillation (AMO), which is known to be correlated with Caribbean SST. Our results fill a void in climate reconstructions for the Caribbean and have the potential for integration into a regional database for greater understanding of past and future climate variation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMEP0480007S
- Keywords:
-
- 0442 Estuarine and nearshore processes;
- BIOGEOSCIENCES;
- 1824 Geomorphology: general;
- HYDROLOGY;
- 3022 Marine sediments: processes and transport;
- MARINE GEOLOGY AND GEOPHYSICS;
- 4235 Estuarine processes;
- OCEANOGRAPHY: GENERAL