Implementing a new method to measure δ³⁴SSO₄ in ice cores to assess sulfate sources in West Antarctica ...

• Main Author: Doyle, Emily
• Format: Thesis
• Language: English
• Published: Apollo - University of Cambridge Repository 2021
• Subjects: Sulfur isotopes; West Antarctica; Mass spectrometry; MC-ICP-MS; Sea ice; Antarctic; Dyer; Dyer Plateau; Antarc*; Antarctica; ice core
• Online Access: https://dx.doi.org/10.17863/cam.80155; https://www.repository.cam.ac.uk/handle/1810/332711

Sulfate sources in Antarctica can reveal information about the interconnection of climate systems and past climate events. The major sulfate sources in Antarctica are sea salt, biogenic activity, and volcanic activity, though volcanic events have a limited ~1–2 year deposition period. Each source can be identified by its unique sulfur isotopic composition of sulfate (δ³⁴SSO₄). However, δ³⁴SSO₄ measurements in Antarctic ice cores are scarce and have poor temporal resolution due to the large sample volume required for isotopic analysis. For this thesis, I established a new method to measure δ³⁴SSO₄ in ice cores via multicollector inductively coupled mass spectrometry (MC-ICP-MS) at the University of Cambridge. This technique requires < 30 nmol of sulfur compared to the ~1 µmol previously required for analysis with gas source mass spectrometry (GS-MS). Using this method, I produced the first seasonal record of δ³⁴SSO₄ in an ice core to reconstruct sub-annual changes in sulfate sources at Dyer Plateau in West ...