LDEO Earth Science Colloquium presents:
Tracing the Effects of Giant Asteroid Impacts on Early Life
Dr. Nadja Drabon, Assistant Professor of Earth and Planetary Sciences, Harvard University.
Abstract: Large asteroid impacts profoundly influenced the evolution of life on Earth during the Hadean and Archean Eons (>2.5 Ga). Archean rocks record at least 16 major impact events caused by bolides larger than 10 km. However, their effects on early surface environments and life remain poorly constrained. I will present data on two ~3.3 Ga impact events, the S2 (37–58 km diameter impactor) and S8 (36–66 km) impacts, and discuss their effects on the biosphere. Both show intense, short-lived environmental consequences, including tsunami-driven erosion, atmospheric heating, and enhanced weathering. These impacts likely injected massive amounts of dust into the atmosphere, leading to years to decades of darkness. Although a short-lived decimation of photosynthetic organisms and life on land is expected, life likely rebounded rapidly, driven by nutrient injection, the development of new ecological niches, and the inherent robustness of microbial life. These results illustrate how impacts could both threaten and promote life on early Earth and potentially on other rocky planets.
Host: Dr. Sarah Hurley, Lamont Assistant Research Professor, Biology and Paleo Environment, LDEO
The Earth Science Colloquium Series, sponsored by Lamont-Doherty Earth Observatory and Columbia University Department of Earth and Environmental Sciences (DEES), provides a lively forum for discussing a wide variety of topics within the Earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO. Colloquium attendance is required of all pre-orals DEES graduate students.
