Coronavirus Information for the UC San Diego Community

Our leaders are working closely with federal and state officials to ensure your ongoing safety at the university. Stay up to date with the latest developments. Learn more.

Geophysics seminar: Mark Jellinek (UBC) "The climate footprint of Earth’s super continental cycles"


 
10/29/2019 - 12:00pm
Location: 
Revelle Conference Room (IGPP 4301)
Event Description: 

Talk abstract:

Supercontinent assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic-continental mantle temperature variations that regulate volcanic and weathering controls on Earth's long-term carbon cycle for a few hundred million years. Whereas the relatively warm and unchanging climate of the Nuna supercontinental epoch (1.8-1.3 Ga) is potentially characteristic of thorough mantle thermal mixing, the extreme cooling-warming climate variability of the Neoproterozoic Rodinia episode (1-0.63 Ga), as well as the more modest but similar climate change of the Mesozoic Pangea cycle (0.3-0.05 Ga) are potentially effects of subcontinental mantle thermal isolation with differing longevity. A tectonically-modulated carbon cycle model coupled to a one-dimensional energy balance climate model predicts the qualitative form of Mesozoic climate evolution expressed in tropical sea-surface temperature and ice sheet proxy data. Applied to the Neoproterozoic, this supercontinental control on can drive Earth into, as well as out of, a continuous or intermittently pan-glacial climate, consistent with aspects of proxy data for the Cryogenian-Ediacaran period. The timing and magnitude of this cooling-warming climate variability depends, however, on the detailed character of mantle thermal mixing, which is incompletely constrained. Furthermore, LIP volcanism, the predominant modes of chemical weathering and a tectonically-paced abiotic methane production at mid-ocean ridges can modulate the intensity of this climate change. In marked contrast, for the Nuna epoch, the model predicts a warm and ice-free climate.

For more information on this event, contact: 
Ignacio Sepulveda
Event Calendar: 
Seminars
Geophysics
sharknado