Speaker: Craig Martin, Department of Earth and Planetary Sciences, The University of Texas at Austin
Title: Obtaining paleomagnetic time-series records from corals
Host: Luc Lavier
Abstract: Unlocking the coral record for paleomagnetic study would provide a rich new avenue to investigate the evolution of geomagnetic anomalies and excursions. Present-day anomalies migrate tens of kilometers per year and experience rapid fluctuations in their magnetic intensity that cause heightened vulnerability to geomagnetic storms. An absence of annual or sub-annual time-precision paleomagnetic time-series datasets hinders our ability to study pre-historical geomagnetic field variations and understand the dynamics of geomagnetic field behavior on human-timescales. I will present a novel framework to obtain paleomagnetic records from corals that have the potential to establish sub-annual paleomagnetic time-series records.I will show that modern coral specimens from the southwest pacific preserve a stable magnetic remanence that is consistent with the geomagnetic field where the coral grew. I will discuss the mechanisms of magnetic remanence acquisition and the origins of ferromagnetic particles contained in modern coral skeletons.