Changes in the Rate of Ocean Crust Production Over the Past 20 Myr: Implications for Sea Level, Mantle Heat Loss, and Climate
withDr. Colleen Dalton, Professor of Earth, Environmental, and Planetary Sciences, Brown University.
ABSTRACT: The rate of ocean-crust production exerts control over mantle heat loss, sea level, seawater chemistry, and climate. Reconstructing ocean-crust production rates back in time relies heavily on the distribution of present-day seafloor age. How best to account for the incomplete preservation of older seafloor has led to differing conclusions about whether production rates have changed significantly since the Cretaceous, with concomitant implications for the importance of seafloor spreading to global climate change. We have constructed a new global synthesis of crust production along 18 mid-ocean ridges for the past 19 Myr at high temporal resolution. We find that global crust production declined by 37%, global ridge length stayed fairly constant, and the globally averaged spreading rate decreased by 38% from the mid-Miocene to present. We investigate the implications of these changes for sea level, mantle heat flow, and climate.
Hosts: Alberto Malinverno, Lamont Research Professor, Marine and Polar Geophysics; Christine McCarthy, Lamont Associate Research Professor, Seismology, Geology and Tectonophysics.
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. The Colloquium Series supports the Lamont Seminar Diversity Initiative.