We are currently developing magnetometers – devices capable of measuring the magnetic record of rocks – using low-cost, off-the-shelf technology. We plan to use them to investigate past changes in Earth’s magnetic field recorded by lava flows of the Columbia Plateau. Previous studies have identified lava flows in Central Washington and Northern Oregon that may have formed while Earth’s magnetic poles were in the process of switching locations. Such reversals have occurred many times through the planet’s history, but their details remain a mystery, mainly because they occur over a few-thousand-year time scale – quick, geologically speaking. Thick lava flows such as those in Central Washington cool over similar time scales, recording Earth’s magnetic field as they do so. Because they typically form steep cliffs, these lava flows are difficult to sample directly, so remote measurements by drone will give us insights not available using other sampling or surveying techniques. Information about Earth’s magnetic field during polarity transitions will help us better understand whether the current weakening of Earth’s magnetic field signals a reversal.
Along with UWT students and collaborators from Green River Community College and Lincoln High School, we are currently building and testing a drone-mounted magnetometer for aerial magnetic surveys. Eventually, we expect that the low-cost magnetometers produced using this project will be replicated at other community colleges and high schools, allowing students at those institutions to initiate their own investigations. Ultimately, our goal is to make geophysics more accessible to the public using the model of the Quake Catcher Network in seismology (http://quakecatcher.net) or the Public Lab in visible light spectrometery (https://publiclab.org/).