Tectonic Problems

Seismologist Explores Volatile Dynamics of the Earth’s Crust

Marine seismologist Dr. William Bythewood Hawley will speak at the Suffolk County Vanderbilt Museum on Thursday, May 5, at 7:00 pm. His lecture, Tectonic Problems: Why the Foundations of Modern Geology Remain Elusive,” will introduce listeners to contemporary debates in geology and the theory of plate tectonics.

The modern theory of plate tectonics holds that the Earth’s lithosphere is composed of several large plates that have been slowly moving across the planet’s surface for 3.4 billion years. These plates, which are cool, relatively solid masses, are thought to ride on the less dense, fluid-like asthenosphere. Over time, the theory of plate tectonics maintains that these plates will collide and separate, causing earthquakes, mountains, and other dramatic geophysical phenomena, all while gradually rearranging the continents.

Our understanding of the volatile dynamics of the Earth’s crust – the modern theory of plate tectonics – represents a relatively recent scientific accomplishment. Based on Alfred Wegener’s 1912 description of “continental drift,” the modern theory of plate tectonics remained highly contentious until the early 1960s. Even today, there are many issues with the theory that stir significant scientific controversy.

In Tectonic Problems, Hawley will explore some of what remains unknown in the current theory of plate tectonics. He will explain how the theory of plate tectonics while offering a compelling qualitative picture of long-term Earth evolution, isn’t quite a theory but something more like a series of observations. He will explore the missing ground—the dynamical description—that the theory lacks and point to the key questions researchers must answer before further developing the theory. He will ask, how is the bottom of a tectonic plate defined? What does it look like? And how does it interact with the mantle underneath? In raising these questions, Hawley will strike at the core of geology and the modern scientific process.

Hawley is a National Science Foundation Postdoctoral Fellow at Lamont-Doherty Earth Observatory at Columbia University. He completed his Ph.D. at the University of California, Berkeley, in 2019, and his B.A. in physics and astrophysics from Harvard in 2012.