Earth's crust feels solid and still beneath our feet, but under the surface there is a shifting jigsaw puzzle of sections called tectonic plates. Fossils show that the birds we see today evolved from dinosaurs. Minnesota has some of the oldest rocks in the world. They're about 3.6 billion years old. We know these startling facts because earth scientists asked questions and searched for answers.
Geologists study the Earth, the forces that act on it, and the history of life. They often see the world differently than others do. To a geologist, the North Shore of Lake Superior isn't just a beautiful place. The lake marks the spot where the North American continent almost split apart 1.1 billion years ago. And the smooth slabs of bedrock aren't just a great place to sit. The rocks were once molten lava, which rose from deep inside the Earth and flowed across the land.
Earth scientists investigate questions all over the world. While working outdoors, a geologist might have to huddle inside a tent on cold, windy days or crawl through limestone caves. In an office, a geologist might examine rocks with a microscope for evidence of gold. Some geologists work for companies that search for valuable minerals (particles within rocks) or oil (used to make gasoline, plastics, or other products). Others help cities clean up water and soil polluted by spills of gasoline or other toxic substances. Still others do government or university research on ancient sea life, volcanoes, or earthquakes.
This story looks at the work of three earth scientists in Minnesota.