Postdoc Spotlight - Ryan C. Porter

Ryan Porter
DTM Postdoctoral Fellow, Ryan Porter, on the top of Mount Humphreys overlooking Sunset Crater in Arizona.
Monday, November 18, 2013 

Ryan C. Porter grew up in Seattle with a knack for white water rafting. While working as a raft guide in Alaska the summer after his freshman year at Whitman College in Walla Walla, Washington, he was blown away by the mountains and glaciers surrounding him. As he was gliding downriver describing the rugged terrain to his tour groups, he realized he really didn’t know much about how the Earth around him evolved into the landscape seen today. When Ryan returned to school that fall, he immediately switched his major to geophysics and hasn’t turned back.

Ryan now works at Carnegie Institution for Science in the Department of Terrestrial Magnetism (DTM) as a Postdoctoral Fellow under the guidance of Staff Scientist, Diana C. Roman. His research focuses on utilizing seismic imaging techniques to better understand plate tectonics and the behavior of the lithosphere, or Earth’s crust and upper mantle. His work has taken him down into the deep valleys and high peaks of the Sierra Nevada and Rocky Mountains, to the lush jungles of the Peruvian Amazon, and to the high Andes of Argentina.

An "x-ray" image from the Colorado Plateau. Top: Receiver Function cross-section across the Colorado Plateau, the red line is the base of the crust. Bottom: Shear-velocity cross section across the Colorado Plateau from ambient-noise tomography. (Ryan Porter)

Currently, Ryan is using natural source seismology to take “x-ray” images (pictured left) of the interior of the Earth at Sunset Crater, the youngest of 600 volcanoes in the San Francisco volcano field in northern Arizona. These images are created by using seismic waves from earthquakes and other sources all over the Earth to “see” into its deep interior. Sunset Crater erupted only 1,000 years ago, making it one of the most recent eruptions in the Western US interior.

Most of Earth’s volcanoes are located at plate interfaces, where two plates come into contact with each other and move at varying rates and directions. Often, the interaction of these two plates results in the condition necessary to unleash tremendous amounts of energy in the form of earthquakes and volcanic eruptions. The San Francisco volcanic field is an enigma in that it is not located near any major plates boundary meaning that some other process must explain the eruptions that occurred there. By deploying seismometers in the region to look for small earthquakes associated with magma movement through the crust and to record real-time earthquakes around the world, Ryan and his team, will produce these “x-ray” images to see deep into the Earth beneath the volcanic field to understand why the volcanoes are there and how they erupt in the region.

Ryan will be attending the American Geophysical Union (AGU) Fall conference this December to give two talks. The first will be, “Ambient Noise Imaging of Craton Modification: Examples from the Kaapvall Craton” on his work in South Africa, and the second will detail, “Seismic Imaging of Flat Slab Subduction: Examples from the Pampean Flat Slab Region” from his work in Chile and western Argentina.

From a raft guide in Alaska to seismologist on Sunset Crater, Ryan will be moving on from DTM in January 2014 to become a Professor at Northern Arizona University in Flagstaff.

Written by Robin A. Dienel

November 15, 2013