We can't directly measure the Earth's core, so we study its magnetic field. What about the early core? That data is stored in ancient rocks.
The Earth Magnetism Lab is where Aleksey Smirnov, an associate professor of geophysics, peels back the layers of old data in rocks and meteorites. The lab is in the very bottom of the Dow Building on campus and Smirnov's basement is way cooler than ours. We politely call our University Marketing and Communications floor the "garden level."
A lot of creativity happens in our garden-level basement. But we don't always get to see where the magic happens—or rather, The Science. So every once in a while, we set up lab tours; this time, we found out why they don't allow any hammers on the floor of the Earth Magnetism Lab. (You'll have to read all the way through to find out why.)
Tour the Earth Magentism Lab
What happens when the Michigan Tech writers and print folk and webmasters escape their garden level offices in the Admin building? Lab tours. We toured the Earth Magnetism Lab, where some of the oldest rocks in the world reveal their iron-locked secrets.
Old Rocks and Meteorites
Aleksey Smirnov directs the Earth Magnetism Lab. His PhD student Marine Foucher and undergrad assistant Katie Bristol gave us a tour, showing everyone the sample prep room and the magnetically shielded room that houses two magnetometers.
The lab equipment do two things: understand the strength and alignment of magnetic signatures in rocks #mtulive— MTU Research (@mturesearch) February 16, 2017
Meet the Magnetometers
In order to analyze the magnetic strength and alignment of rock samples--which reveal details about the Earth's ancient magnetic field--Smirnov, Foucher, and Bristol have to run tests using a magnetometer. Theses are no ordinary magnetometers; they are specially designed to extract magnetic signatures out of rock samples, which require a special temperature treatment so the data locked in the rock's iron-rich minerals doesn't become distorted.
The machine is a super-conducting magnetometer that measures bulk rock samples. Marine named it Big Bob. #mtulive— MTU Research (@mturesearch) February 16, 2017
Since researchers cannot visit the core, they use rocks at the surface as a proxy. Specifically, volcanic rocks record the intensity and changes in Earth's magnetic field and the record extends back billions of years to the early days of the planet's young core and the development of the geodynamo.
The hammer thing: think about it. In a magnetically shielded room, where precision equipment rules with an iron fist, would you want any metal about that could warp the low-magnetic environment? No. So, don't leave your hammers on the floor.
Michigan Technological University is a public research university, home to more than 7,000 students from 54 countries. Founded in 1885, the University offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, forestry, business and economics, health professions, humanities, mathematics, and social sciences. Our campus in Michigan’s Upper Peninsula overlooks the Keweenaw Waterway and is just a few miles from Lake Superior.