Searching for clues in icy watersResearchers often travel to the ends of the Earth in the name of science. In Katie Schreiner's case, science brought her to the top of the world. This past August, the oceanography doctoral student collected sediment samples off the northern coast of Alaska to better understand how climate change is causing shrubs like birch and willow to expand their coverage. Over the years this vegetation stunted by the Arctic cold, has been expanding farther, a visual record apparent in aerial photos of the Alaska North Slope from the late 1940s to more recent times. While researchers think this expanding coverage is driven by climate change the exact mechanism—rising temperatures, melting permafrost or increased microbial activity—is unknown. So researchers like Schreiner extract the chemical record from sediments for evidence of past growth patterns of woody plants. Schreiner and her fellow researchers spent five days in August on a small boat north of the Arctic Circle. They concentrated their efforts in Simpson Lagoon, an area in the Beaufort Sea near the outlet of the Colville River. Their work kept them close to shore in shallow water and brought them near sea ice. "One day the captain asked us if we wanted to walk on the icebergs," Schreiner says. After hesitating, they walked out onto an iceberg that turned out to be much more stable than they had thought. "Everyone was scared to be the first one out," Schreiner says. "The ice looked like it would start rocking if we stepped on it." Schreiner and her colleagues spent most of their five days doing seismic surveys to find places to collect sediment cores. Nobody has taken cores like this in Simpson Lagoon before, Schreiner says. "It's a very understudied area, so we wanted to make sure we got the best places." It also took about half a day for them to get the hang of working from a small boat and shallow water, she says. Once that happened, they were able to collect four cores in one day and two more on their last day out. They left the Arctic with five 2.5-meter-long cores and one shorter one that came from a spot with either permafrost or a thick layer of clay they couldn't punch through. Schreiner has just started her work with the cores, which she says should keep her busy for the next two or three years. Schreiner earned her bachelor's and master's degrees—in chemistry and Earth science, respectively—at Purdue, where her undergraduate adviser sparked her interest in environmental issues. This interest led Schreiner to the College of Geosciences, which she says is larger and more diverse than the Earth science department at Purdue. A big advantage of studying here, Schreiner says, is the sheer number of opportunities she has had for research and field work. "I don't know that I would have found that somewhere else," she says. Dr. Tom Bianchi, her faculty advisor oversees several research projects in diverse areas, she says. "We always have chances to gain research experience outside our main research areas," she says. Bianchi also pushes his students to be more thorough, which Schreiner says is great in an advisor. Schreiner took advantage of one of Bianchi's many projects when technical problems delayed her trip to the Arctic for a year. The research project required investigating the effects of marsh subsidence on waters off the coast of Louisiana, and Schreiner helped out by studying Gulf of Mexico sediment cores. While this research was unrelated to her main focus, she says it was good to get more research experience and to work with lab procedures that will help in her Arctic work. After completing her doctorate, Schreiner plans to continue applying her knowledge of chemistry to address environmental problems, and she wants to teach and continue doing research. "I like both, so I want to find a good mixture," she says. Story by George Hale '99 |


