[DLS] Roger Fu (Harvard)

“Understanding Early Earth and Mars Using High-Resolution Paleomagnetism”

Plate tectonics and a magnetic core dynamo represent two fundamental links between the interior dynamics of a planet and its surface environment. Paleomagnetic studies have documented these processes over most of Earth history, but the sparse rock record severely limits our understanding at ages greater than about 3 billion-years-ago (Ga). I will discuss how recently developed magnetic field imaging techniques have enabled new ways to retrieve and verify ancient magnetic signals preserved in complex samples, including early Earth rocks and martian meteorites. These studies have demonstrated the existence of mobile-lid plate tectonics and a reversing geodynamo on Earth as early as 3.5 Ga and the persistence of a martian dynamo until <3.9 Ga, approaching the time of active hydrology in the late Noachian.

EAPS Department Lecture Series —

Weekly talks aimed to bring together the entire EAPS community, given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Runs concurrently with class 12.S501.

Contact: eapsinfo@mit.edu