Nigel Wattrus
Large Lakes Observatory

I was born in England and grew up in the English Midlands, near Birmingham ( a large industrial city - a lot like Detroit). I became interested in Geology while still in high school and eventually went to the University of Birmingham to study Geology as an undergraduate. While at Birmingham, I became interested in Geophysics—how the Earth "works". What is an earthquake? What can we learn about the Earth's interior from studying them?

After receiving my degree from Birmingham I came to the USA to study Geophysics at the University of Minnesota. My PhD research there focused on how we can use imaging techniques used in medical X-ray CT scanners to construct pictures of the Earth's interior. This technique, called tomography, has been widely used to reconstruct the internal structure of an object from measurements made on its surface (ie. how much sound/x-ray energy we can transmit through it). Scientists have used tomographic techniques to build 3D pictures of the Earth's interior. Others have used them to measure the temperature fluctuations in the world's oceans from sound transmission experiments.

After completing my PhD, I spent 11 years in Texas working at the research lab of a major oil company. There I studied how we can apply some of these advanced imaging techniques to building better pictures of where oil and gas accumulate in the Earth.

I returned to the University of Minnesota in 1995 to join the newly established Large Lakes Observatory (LLO) in Duluth. Here I have focused on developing acoustic techniques that allow us to image the lake floor and the sediments below it. Sun light does not penetrate very deep into a lake, so we use sound to take "pictures" of the lake floor. Among the methods I use are seismic methods, which use sound waves to generate reflections off the sediment layers below the lake floor, and sidescan and multibeam sonar which allow us to build extremely accurate pictures of the shape and composition of the lake floor. Since coming to the LLO I have worked on lakes in Africa and Central America, but most of my time has been spent working on Lake Superior.

Learn about more Bell LIVE! host researchers:

• Mary Balcer, University of Wisconsin-Superior
• Doug Jensen, Exotic Species Expert
• Teresa Norberg King, Environmental Protection Agency
• Don Schreiner, Lake Superior Area Fisheries Advisor, Minnesota Department of Natural Resources
• Nigel Wattrus, Large Lakes Observatory, University of Minnesota