Jones Faculty Lecture by Tamara Carley, Associate Professor of Geology and Environmental Geosciences

“What lies beneath retreating ice? Evidence from young, historically-overlooked volcanoes emerging from Vatnajökull ice cap, Iceland”

Iceland is located at the intersection of an active mid-ocean ridge, a mantle plume, and the periphery of the Arctic Circle. This unique position results in globally-significant magma production and complicated interactions between erupting volcanoes and a changeable climate. During its ~20 million year history, the currently-temperate island has experienced balmy, ice-free, conditions and frigid periods with complete ice-coverage extending out to sea. Vatnajökull—an icecap that covers ~10% of Iceland’s land area—sits on top of the junction of the ridge and plume, and with it, some of the island’s most active and hazardous volcanoes. Vatnajökull is shrinking in response to climate change; it has lost approximately 15% of its volume in the last 100 years. This is cause for alarm, as rapid and significant ice-loss can destabilize shallow magma bodies and trigger volcanic eruptions. It also presents a rare opportunity to investigate a dynamic and enigmatic region of Iceland that has been hidden from view for the entirety of its human habitation. Small, isolated, protrusions of rock called nunataks rise above the thinning ice—they are the peaks of large, subglacial, volcanoes. Diverse piles of jumbled rocks called moraines form along the margins of retreating outlet glaciers; each rock was ripped from a young volcano or older bedrock and transported to its resting place by flowing ice. Together, these nunataks and moraines provide the physical, chemical, and chronological evidence necessary to probe the magmatic history of southeastern Iceland. Geologists are guided by the notion that the present is the key to the past and the past is the key to the future. The recent past of subglacial volcanoes beneath Vatnajökull, interpreted in the context of today’s rapidly changing climate, impresses upon us the need to better prepare for a potentially-hazardous future in the land of fire and ice.  

The talk is sponsored by the Thomas Roy and Lura Forest Jones Faculty Lecture and Awards Fund, established in 1966 to recognize superior teaching and scholarship at Lafayette College.