Yiying Le

Title of Project

Reconstructing Past Earth-Moon Distance and Length-of-Day Using Geological Data

Postgraduate Research Summary

I am beginning a PhD project focused on reconstructing the dynamic history of the Earth-Moon system using geological data.

The current lunar recession rate measured by lunar laser ranging (~3.8 cm/year) suggests the Moon would have been extremely close to Earth only 1–2 billion years ago, which is inconsistent with its known age of over 4.4 billion years. This suggests that the lunar recession rate varied which is also indicated by various geological archives.

My research aim focusses on new high-resolution cyclostratigraphic records from Carboniferous sedimentary sections in Ireland and other sections to constrain past variations in the length-of-day and Earth-Moon distance. Using Bayesian statistical modelling, I will integrate these new records with existing models and global datasets.

Previous Research Experience

My undergraduate capstone project, New Insights into Magma Evolution Prior to the 1538 Monte Nuovo Eruption (Italy) from Clinopyroxene Trace Element Zoning, investigated pre-eruptive processes at the Campi Flegrei caldera.

Using SEM-EDS and LA-ICP-MS trace element mapping, I examined “cryptic” zoning patterns in clinopyroxene crystals to reveal evidence of multiple smaller magma recharge events and volatile saturation before eruption.

This work provided valuable experience in high-resolution analytical techniques and data interpretation, preparing me for the multidisciplinary approach required for my PhD research.

Name of Supervisors

Dr. Matthias Sinnesael

Dr. Micha Ruhl

Postgraduate Personal Details

I completed a B.A. in Geosciences at Trinity College Dublin, where I developed expertise in sedimentology, volcanology, and advanced geochemical techniques.

My passion for planetary processes stems from a lifelong interest in astrophysics and a fascination with how geological archives can reveal the dynamic evolution of our solar system.

Project Start Date

September 2025

Funding

Self-funded

Contact Details

Email: yile@tcd.ie