Why Earth's Pacific Side Is Cooling So Much Faster
3 days ago
- #geophysics
- #mantle-convection
- #plate-tectonics
- The Pacific hemisphere cooled about 50 Kelvin more than the African hemisphere over the last 400 million years due to differences in lithospheric heat loss.
- Oceanic lithosphere (dominant in the Pacific) cools faster due to thin crust and efficient hydrothermal cooling, while continental lithosphere (dominant in Africa) retains heat longer due to its thickness and low conductivity.
- The study used computational models integrating seafloor age, continental positions, and lithospheric properties to analyze hemispheric heat loss patterns.
- Mantle convection and plate tectonics play a key role, with faster-moving Pacific plates indicating an initially warmer mantle that cooled more rapidly.
- Hydrothermal systems at mid-ocean ridges significantly enhance heat loss, requiring models like CHABLIS to account for advective cooling mechanisms.
- Supercontinent cycles influence mantle convection, leading to phenomena like large igneous provinces (LIPs) and affecting long-term climate through volcanic gas release.
- The findings highlight that planetary heat loss is uneven and deeply tied to plate tectonics, from small-scale shear zones to hemispheric-scale dynamics.