Observer Exclusive: Vulcanologist Comments on Shuddering Tectonic Plates Beneath Manhattan

After the gentle swaying subsided and we emerged from stunned silence, we called William Melson, Senior Scientist Emeritus at the Division of Petrology and Volcanology at the Smithsonian. Mr. Melson lives in the Shenandoah Valley, but he spoke with us from Arlington.

The epicenter, he tells us, is a small Virginia hamlet named Louisa, but tremors were felt as far south as North Carolina and as far north as New York.

“It’s an unusually large earthquake for the eastern U.S.,” he tells us. “We have smaller ones but this is large. The USGS says 5.9 magnitude. 3.7 miles deep.”

In layman’s terms: “that’s enough to knock things off the shelf and scare the heck out of people but not do major damage.”

What about aftershocks? Should we evacuate? (Can we evacuate? It’s really nice outside.)

“Often from one that small you don’t have aftershocks,” says Mr. Melson.


“That was probably the primary quake,” he said. “It was pretty inconsequential. A four is going to be enough to alarm everybody because we’re not used to it.”

Inconsequential? It might be a small earthquake, but it’s our earthquake.