Post your questions here for Paul Morin. We'll pick the best ones and post his answers.
Paul Morin creates giant maps, 3D models, and virtual reality simulations of the Earth for the University of Minnesota and the National Center for Earth Surface Dynamics. He’s spending the polar summer making a 3D map of Antarctica’s Dry Valleys.
To make his model, he’ll use aerial photos, images from spy satellites, digitized paper maps, and old-fashioned walking around and looking at the landscape.
The McMurdo Dry Valleys of Antarctica are among the driest places in the world. Free of ice and snow, these deserts fascinate geologists because a labyrinth of igneous rock is exposed in the Valley walls like nowhere else on Earth.
Obvious geologic formations called dikes and sills are the remains of a “plumbing system” that allowed magma—molten rock—to work its way to the Earth’s surface 180 million years ago. As the magma welled up inside the Earth, it forced its way between layers of rock deep beneath the surface. After it cooled, erosion created the Dry Valleys, revealing the structure of the rock walls.
Scientists usually have a tough time studying volcanic plumbing systems because lava covers everything. Even at ancient volcanoes, deeply cut by erosion, geologists can normally only see the interior of the volcano itself, not the structure of the rocks below. But in the walls of the Dry Valleys, trained eyes can see magmatic sills—the horizontal layers of once-liquid rock that fed the volcanoes.
Geologists want to know not only where the magma went, but also how it cooled.
Morin says, “We are creating a fully three-dimensional model that help show data you can’t see on a paper map. What was the cooling rate? How quickly did the event occur?”
Why does it matter? Depending on how quickly it cools, magma has different characteristics—big or small crystals, rough or smooth, dull or shiny. The magma revealed in the walls of the Dry Valleys also carried with it rock crystals from deeper inside the Earth. As the magma cooled, gravity arranged the crystals in a characteristic way. By decoding that crystal structure, looking at the surrounding rock, and collecting other geological data, the scientists in Antarctica are hoping to understand how magmatic systems like the one revealed in the Dry Valleys form—an understanding that might also explain how the Earth as we know it formed.