[ESS] Murray Ford (University of Auckland)

“The Evolution of Atoll Islands: From Formation to Modern Dynamics”

Catastrophic shoreline erosion as a consequence of sea level rise (SLR) is expected to destabilise low-lying islands perched on coral reefs throughout the tropical and subtropical oceans, destroying the islands and in cases rendering their populations climate change refugees. Recent remote sensing studies have challenged this assumption, revealing a surprising trend: the majority of reef islands have expanded in size since the mid-20th century, despite well-documented SLR. Over the past two decades several studies have attempted to establish chronologies for the formation and development of individual islands by using radiometric dating of island sediments. These chronologies indicate that reef islands in the Pacific formed in the mid- to late Holocene, approximately 5,000 to 1,000 years ago. However, despite the increasing number of island formation chronologies, there is a scarcity of published radiometric dates indicating the contribution of modern materials to observed island growth. The disparity between chronological studies largely devoid of recent sediments, and remote sensing records which show active growth of islands will be explored in this seminar, drawing upon recent evidence from reef islands in the Pacific and Indian Oceans.

Earth Science Seminar —

Lecture portion of the EAPS graduate-level class 12.571, covering current research in geophysics, geology, geochemistry, and geobiology. All members of the MIT community are welcome to join for presentations by guest speakers, held approximately every two weeks during the term.

Contact: earth-science-seminar-info@mit.edu