Editor’s note: The Lab Report is a weekly series in The Badger Herald’s print edition where we take a deep dive into the (research) lives of students and professors outside the classroom
The WiscAr Geochronology Lab uses geochronology to study how climate system changes on our planet’s surface, such as deglaciation and rising temperatures, affect processes under the earth.
One such project studies active volcanoes in Chile that were once covered by a thick Patagonian ice sheet that began melting 18,000 years ago. WiscAr researchers strive to learn more about the growth rates and eruptive histories of several dangerous volcanoes by studying each volcano in great detail using geochronology — the study of dating rock formations, geological events and mineral chemistry.
This project’s goal is not only to gain knowledge of the interactions between volcanoes and ice sheets but also to train students from communities living near these volcanoes. Director of the WiscAr laboratory Brad Singer said the Patagonian ice sheet melted in only about 2,000 years, providing scientists with a natural laboratory experiment on the effect of receding ice sheets on volcanoes.
“The aim is to try to see what makes a volcano sensitive to eruptions triggered by the ice loss,” Singer said. “We want to try to study that relationship between the cryosphere and the magma in the lithosphere.”
The lab is working to develop a new Lower Cretaceous Time Scale through international collaboration. The Cretaceous period, from 125-93 million years ago, was a time of global warming in which atmospheric carbon dioxide levels surpassed 800 ppm — this number is similar to predictions for 2100 if emissions continue on the same course.
By studying Cretaceous marine sediment in this area and creating a common temporal framework, collaborators from the U.S., England and Japan hope to gain insight into the future of the carbon cycle and greenhouse scenarios.
Singer began studying the Chilean volcanoes in 1991 as a postdoc at Southern Methodist University. He said he jumped at the chance to work in the warm region of Chile, as he had been doing similar work in the much less hospitable Aleutian Islands of Alaska.
Singer said fieldwork in Chile is no easy feat, either. The volcanoes are surrounded by dense forests and with no roads nearby, so it’s necessary to backpack to the interior of the volcanoes and even take a helicopter in some instances.
While working on a volcano in the southern Andes Mountains, he and his colleagues discovered a lava flow reversal of Earth’s magnetic field captured in frozen metal, Singer said. This discovery opened up a whole parallel line of research for him involving paleomagnetism that Singer says has become quite successful. The project Singer is working on now is the result of 30 years of work on these volcanoes.
“This is kind of the culmination of years worth of thinking about these problems, which I’m really excited about,” Singer said. “A lot of the findings depend on getting as accurate and precise of a chronology using the spectrometers and methods we’ve developed over the last 30 years.”
According to Singer, the WiscAr laboratory utilizes a powerful metric used to date samples called the 40Ar/39Ar dating method. This method can be applied to a wide variety of disciplines including but not limited to volcanology, igneous petrology, climate change in deep time and refining geomagnetic time scales.
The WiscAr Geochronology lab collaborates with many researchers and institutions on numerous large-scale projects whose goal is to gain a deeper understanding of the Earth’s history.
Research specialist at the WiscAr laboratory Bryan Wathen is responsible for extracting potassium-rich phases from whole-rock samples, preparing samples for irradiation and analysis and sample information logging and tracking.
“The best part of working in the lab is the fact that we work and collaborate with so many different people from different universities around the country and around the world,” Wathen said.
Another area of research for the lab is the Green River Early Eocene Climate Observatory, also known as GREECO. This study examines the deep-time geological records of the Early Eocene Climatic Optimum, also known as EECO, was a period between 50-53 million years ago which was characterized by warm temperatures across the globe. The researchers study the EECO through the investigation of alkaline lake strata of the lacustrine Green River formation.
Researchers chose this time period to study because of its characteristic abrupt warming episodes. Ph.D. student in the lab Benjamin Bruck, who works on the GREECO project, said that understanding how earth systems responded to that warming event is really important because we’re also experiencing a warming event now. Bruck said the past is the key to understanding the present.
The EarthCube Integration, another project that the WiscAr lab is involved in, will use data from some of the previously discussed studies and data from a few other labs, Singer said. This project combines efforts from geoscientists, geochronologists and computer scientists who aim to develop a four-dimensional digital Earth in order to fully understand dynamic Earth system evolution through time.
Though the studies that the WiscAr laboratory works on span continents, geological disciplines and millions of years, what connects them all is geochronology.
“To boil it down to a simple phrase, no dates, no rate. If we want to look at the rate of Earth system processes, which is really key to understanding how things work, you need geochronology,” Singer said.