The effects of the Earth's magnetic fields are at the center of IRM research.

The Institute Director, Subir Banerjee, says that the IRM is committed to research and service in the geological sciences. Professor Banerjee began research and teaching at the University of Minnesota in 1971, and his initial projects included studying the magnetism in lunar samples and the magnetic remnants along oceanic crusts. “This is a nice place,” says Banerjee about Minnesota, “because the geomagnetic field seems to have a large non-dipole component here.”

While Minnesota boasts magnetic anomalies, it is not alone in this regard, for Siberia displays similar magnetic features.

When the University first received its grant to become an official research institute, Banerjee’s immediate concern was that the IRM might devolve into a play-field for individual scientists and their esoteric pursuits. He feared the Institute would branch into a dozen separate corners, each filled with a specialist working on a specialized project. Through concerted planning, Banerjee and his fellow University of Minnesota colleagues, Bruce Moskowitz and Jim Marvin, brought about the exact opposite case. Instead of their institute being filled with cul-de-sacs of research, the IRM is a veritable nexus where physics, geology, chemistry, and biology all convene to share information.

Banerjee strives for a synthesis not only in scientific disciplines, but also in global cooperation. Just like Alexander von Humboldt and other wayfaring scientists before him, Banerjee’s investigations of the Earth’s magnetism have led him on travels the world over. Last March, Banerjee visited Uruguay to study movements of aboriginal populations, and his research projects in Yemen taught Banerjee the wider application of magnetism in studying plant migration. Earlier in the decade, Banerjee embarked on a rock magnetism odyssey through India, China, and Japan. International sensitivity and an emphasis on teamwork pervade all of Banerjee’s travels. “Through cooperative research,” he believes, “western scientists can make a difference by lifting the scientific morals of our colleagues and by sharing in field expenses.”

Research at the IRM falls under two broad categories: rock magnetism and paleomagnetism. “Rock magnetism is the nucleus of basic knowledge that we are trying to expand,” says Banerjee. Magnetism itself remains an enigmatic topic in physic, and physicists relish any clues that can aid in constructing an explanation of magnetic behavior.

Rock magnetism investigates the magnetic status of terrestrial samples that are thousands or millions of years old. Although the Earth’s magnetic field is weak compared to familiar magnets, like ones stuck to your refrigerator, the Earth’s field is omnipresent, and it is strong enough to lock iron oxides and other fine-grain minerals into a specific magnetic configuration. For millions and millions of years, rocks preserve the magnetic conditions they knew when they were initially formed. Remnants of magnetism in ancient rocks can guide scientists towards a deeper theoretical understanding of magnetism.

In addition to the “gritty work of rock magnetism,” as Banerjee calls it, paleomagnetism is the type of research that applies information of magnetism to other fields. Geologists, environmental scientists, meteorologists, and more all glean the results of rock magnetism for their own particular projects.

Geologists use magnetic samples to trace plate tectonics and continental drifts. Magnetic clues are a major source for geologists as they assemble pictures of prehistoric land formations. Environmental scientists use magnetism to study environmental change brought on either through human impact or over geological time periods.

Meteorologists use the magnetism of terrestrial samples to study how the climate changed through the millennia. Knowledge of past climate changes can assist modern forecasters in predicting the vicissitudes of odd weather patterns, such as El Nino or La Nina. Furthermore, Anthropologists could benefit by knowing past climates because it informs them what areas were habitable and when.

Climate change through geological time periods is one of the hottest research topics at the IRM. A traveling scholar from the University of California, Irvine studying climate change and environmental pollution brought some samples to the IRM. Shortly after her visit, she announced that the entire direction of her research was shifted thanks to the results she found. The climate changes found by studying lake sediments in the Pittsburgh Basin of south-central Illinois gave graduate student, Christopher Geiss a dissertation topic in rock magnetism and its applications. “Magnetic properties of lake sediments can reflect climatic change and are a useful tool for the reconstruction of paleoenvironmental change,” says Dr. Geiss in the conclusion to his thesis. A fundamental axiom in geology says that the present holds the keys to understanding the past. Geiss and others at the IRM tune their research in harmony with this axiom as they piece together the Earth’s history.

Another active member of the IRM is Senior Scientist and Lab Manager, Mike Jackson, who arrived as a post-doc in 1990. Jackson’s writing and experiments have contributed greatly to the IRM’s success.

Whether analyzing data from mid-ocean ridges or core samples from lake sediments, Jackson says the IRM endeavors to, “use magnetism in anyway that we can to work out questions about the Earth’s history.” Vestiges of ancient magnetic fields are stored in magnetite, fine grains of black iron oxide, that accumulate and stratify at the bottoms of lakes or in oceans. Over geologic time scales, the magnetite grains maintain their magnetization despite the pressures and stresses exerted in the Earth’s crust. “A lot of the work we do is geared toward understanding how these fine grains store and retain magnetic information,” says Jackson.

Soft-spoken and amicable, Jackson is a prolific writer whose articles have graced numerous covers of the IRM Quarterly, a journal that finds hundreds of readers over 6 different continents. Jacksons penchant for history led him to write on topics such as Edmund Halley’s voyage around the Atlantic to chart magnetic declination and Benjamin Franklin’s proposals to explain magnetic phenomena. Jackson also wrote The Hitchhikers Guide to the IRM, a whimsical travel guide for all of the Institute’s visiting scholars.

The Superconducting Magnetometer that detects the true magnetization of a sample

| main | issues | subscribe | advertise | contact | links |