By Ainsley Lord

Faculty Mentor: Dr. Pamela Grothe

Abstract

The tropical Pacific is a major driver for global climate variability through the El Nino Southern Oscillation (ENSO), however, the magnitude of warming and freshening as well as changes in ENSO from anthropogenic climate change in the tropical Pacific is poorly understood due to limited instrumental records and a non-continuous paleoclimate record before 1950 CE. The lowest Line Island in the tropical Pacific, Kiritimati (1.8° N, 157.4° W), lacks continuous high-resolution records from the reliable coral species climate recorder Porites. With more recent techniques focusing on coral rubble pieces as climate proxies has shown promise, we are using large skeletal architectural corals for Favia and Hydnophora species, as they are abundant in the field. However, with their larger skeletal architecture, and their exposure to more weather events on the rubble fields, there is higher risk for dissolution too have occurred from when they grew to the present day. Here, we are looking into how well these corals from rubble fields are preserved by imaging each fossil on the scanning electron microscope (SEM) and ranking each chip depending on the presence of Secondary Crystals and Dissolution. This ranking is completed to get a comprehensive look at chips taken from the top, middle, and base of each coral slab we hope to use in future work. Getting these scans done allows us to see the preservation of each coral and give us an idea of which will be best to be used in our overall goal of creating a nearly continuous high-resolution climate record back to 1800 C.E. This continuous record is critical for understanding the impact of anthropogenic climate change on this region and informing future climate models of climate predictions under increasing greenhouse gas forcings.