Corn syrup mantle plumes.

In the dark, microscopic plastic beads in the 200-gallon tank of corn syrup glow and sparkle when light from a projector shines at them in geophysical fluid dynamicist Christopher Kincaid’s laboratory at the University of Rhode Island. Experiments with this goo could help explain whether columns of magma rising up from near the Earth’s core might explain supervolcanic activity. Scientists have long suggested that giant columns of molten rock, known as mantle plumes, might explain a wide variety of volcanic mysteries. These mysteries include supervolcanoes capable of eruptions dwarfing anything ever witnessed by humanity. Geologists have proposed that a mantle plume lies under Yellowstone National Park, but critics of whether such features exist argue that no single plume can account for the geological complexities seen in that region. Kincaid and his colleagues use their vat of corn syrup to simulate mantle plumes to help resolve such controversies. “We get lots of confused calls from bakers’ supply companies—they wonder what sort of restaurant orders 300 gallons of corn syrup and nothing else,” Kincaid says. Corn syrup has very little inertia, flowing when stress is applied but stopping immediately when the stress is removed. It also has a temperature-dependent viscosity: when it gets cold, it becomes very sticky, and when it gets hot, it becomes runny. In these respects, corn syrup is rather like the mantle. Moreover, the syrup is nontoxic, making it safe and easy to work with. Beads in the syrup help illustrate how the syrup moves. “We once ran a cocktail party in the lab during an experiment,” Kincaid says. “People sipped wine and watched 100 million years of plate tectonic evolution unfold before them.” When a patch of the vat’s floor is heated, a jet of syrup rises up much like mantle plumes supposedly do. The researchers postulate that the Farallon subduction zone beneath the Pacific Northwest could stall, deform, and partially tear any mantle plume under Yellowstone in two, potentially explaining the complexities seen there (1).