Temperatures in the Ross Sea During the Early to Mid-Miocene from Clumped Isotope Analysis

Camilla Martinez

Overview

Antarctica’s peripheral ice shelves are a critical component of the ice sheet’s mass balance, contributing to the sensitivity of the Antarctic cryosphere and global sea-level. Despite being a fundamental aspect of ice-sheet dynamics, the relationship between water temperatures on continental shelves and changes in CO2 conditions has not been clearly determined. This study investigates conditions in the Ross sea over the early and middle Miocene (~23-14 million years ago), when pCO2 was >400 ppmv, using samples from the Antarctic geologic drilling (ANDRILL) program. Clumped isotope data for primary carbonates indicate average temperatures for shelf waters to be >10°C warmer than the present. Some diagenetic carbonates have low water δ18O values, like modern sea ice brines that form from freezing of seawater, with evidence for aragonite-aragonite neomorphism. Given the role of the Ross Sea in affecting ice sheet stability and Antarctic bottom water production, our results can serve as a reference dataset to constrain thresholds for ice shelf disintegration, and Southern Ocean polar amplification.

From the student

My name is Camilla Martinez and I’m currently a senior at North Hollywood High School. My introduction to the geosciences came from working on paleoclimate reconstruction at my UCLA. Reading and discussing papers, attending lab meetings, and being assigned to a diverse array of projects, my attention was captivated by the controversies surrounding the accuracy of paleoclimate modeling versus the proxy approach to climate reconstruction. The sheer potential of research to model the complex relationships between oceanographic, physical geologic events, and human-contributed events and technologies drew me in. Working virtually with my mentor Hannah Tandy, I was able to compile machine outputs, utilize temperature calibrations to compute sample temperatures, and analyze the resulting data for my project. I aimed to contribute to the existing literature on the Ross Ice sheet in order to better determine the effects of changing climate sensitivity and provide an empirical basis for models of paleoclimate and forthcoming climate change.

The Southern California Academy of Sciences Research Training Program was integral in my growth as a researcher. With the pandemic, doing hands-on research became extremely difficult and I felt helpless in controlling how much I research I could conduct. However, becoming a part of the program put me in touch with a multitude of research-inclined students, scientists, and advisors which formed a valuable community for collaboration and the sharing of knowledge. I learned how to approach conducting research remotely from conversing with other members, and was able to apply these ideas to my research.

In my pursuit of research, I hope to apply my research insights into engineering solutions for climate change on a global scale and impart systemic change to slow and remediate global warming. A personal long-term aspiration of mine is to give back to those who aren’t given the same opportunities and by pursuing research; I aspire to contribute my own valuable experiences to being an advocate for diversity and opportunity in the research community. And as a part of the AJAS meeting, I look forward to meeting other like-minded researchers to communicate and discuss research with!