Strange bedfellows: magnetism and climate

The Earth’s climate and magnetic field make strange bedfellows. With a compass, we can use magnetic north to find our way at sea and on land. And we know that the planet’s magnetism derives from the Earth’s molten iron core.

But climate? We look to patterns of wind, temperature and precipitation. You can’t use a compass to tell you if it’s going to rain, but scientists have known for many years that climate and the Earth’s magnetic field move in similar fashion. They don’t understand if they are related and, if so, why.

The JOIDES Resolution in port at Ponta Delgada, Azores. IODP Expedition 339, Mediterranean Outflow. (Credit John Beck, IODP/TAMU)
The JOIDES Resolution in port at Ponta Delgada, Azores. IODP Expedition 339, Mediterranean Outflow. (Photo: John Beck, IODP/TAMU)

Stranger yet is where Chuang Xuan, a postdoctoral scientist at Oregon State University, is looking for clues to solve this mystery: the bottom of the Atlantic Ocean. Xuan has joined an expedition on the research ship JOIDES Resolution to drill deep into the seafloor where the Mediterranean Sea flows into the Atlantic. It is there, he says, that thick sediments deposited by the Mediterranean’s outflow may have preserved variations in climate along with the magnetic history of the planet.

The expedition is part of the Integrated Ocean Drilling Program (IODP), an international research program in which OSU scientists have played a leading role.

According to Xuan, the combination of high sediment accumulation rates and the type of sediment may yield excellent paleomagnetic records — good enough to record small geomagnetic changes that scientists call “excursions” — as well as high-quality paleoclimate data from the same sediment sequences. He plans to study correlations between the two types of records to see whether and how geomagnetic field variation and climate change might be connected.

Chuang Xuan (Paleomagnetist, Oregon State University, USA) and Carl Richter (Paleomagnetist, University of Louisiana, USA) discuss the results of their testing. Expedition 339, Mediterranean Outflow, of the International Ocean Drilling Program. (Credit John Beck, IODP/TAMU)
Chuang Xuan (Paleomagnetist, Oregon State University) and Carl Richter (Paleomagnetist, University of Louisiana) discuss the results of their testing. Expedition 339, Mediterranean Outflow, of the Integrated Ocean Drilling Program. (Photo: John Beck, IODP/TAMU)

A member of OSU’s Paleo-and-Environmental Magnetism Laboratory in the College of Earth, Ocean, and Atmospheric Sciences, Xuan studies the process that causes deep-sea sediments to be magnetized. By deciphering past variations in Earth’s magnetic field, he works to understand the causes and consequences of geomagnetic change. He uses magnetic records from Arctic sediments for paleoenvironmental and stratigraphic applications. He also develops software to process large volumes of paleomagnetic data on sediment cores.

Xuan received his Ph.D. in geology from the University of Florida in 2010. He earned his master’s in applied mathematics in 2005 from China University of Geosciences, Wuhan, where he also received his bachelor’s in geology in 2002.

See weekly trip reports, photos and other information about the expedition.

About IODP

The Integrated Ocean Drilling Program (IODP) is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor. The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP (USIO). Together, Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University, and the Consortium for Ocean Leadership comprise the USIO.  IODP is supported by two lead agencies: the U.S. National Science Foundation (NSF) and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Additional program support comes from the European Consortium for Ocean Research Drilling (ECORD), the Australian-New Zealand IODP Consortium (ANZIC), India’s Ministry of Earth Sciences, the People’s Republic of China (Ministry of Science and Technology), and the Korea Institute of Geoscience and Mineral Resources.