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Full-Text Articles in Physical Sciences and Mathematics
Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans
Reconstructing Deep-Ocean Circulation During Cenozoic Climate Transitions From The Marine Sediment Record, Brian Romans
Sustainability Seminar Series
Ocean circulation plays a critical role in the Earth’s climate system through the storage and transfer of heat and carbon dioxide. The North Atlantic and Southern Ocean are of particular interest because these are regions where deep-water components of global circulation develop. Dr. Romans uses the deep-sea sedimentary record to reconstruct past ocean circulation and its relationship to past climatic and tectonic conditions. He integrates information from a broad range of spatial and temporal scales, from seismic-reflection data that reveals regional sedimentation patterns to high resolution records based on quantitative grain-size analysis from cores. Dr. Romans will present research from …
The Boring Millions? Vegetation, Atmospheric Co2 , And Climate Revolutions Of The Late Miocene, Pratigya Polissar
The Boring Millions? Vegetation, Atmospheric Co2 , And Climate Revolutions Of The Late Miocene, Pratigya Polissar
Sustainability Seminar Series
During the late Miocene (11-5 Ma), global ice volume and deep ocean temperatures appear to be relatively unchanging. These “boring millions” suggest stasis of the climate system with the expectation of only moderate global changes in climate, CO2 and vegetation. However, during this time tropical ecosystems underwent profound changes and surface ocean temperatures declined dramatically. When did these changes occur, what drove them, and what role if any did atmospheric carbon dioxide levels play? I will address these questions through new observations of the onset, pace and geographic extent of vegetation transformations and hydrologic changes reconstructed from molecular biomarkers. I …
The Fate Of Sulfur During Melting And Crystallization: Implications For Sulfur Transfer From Mantle To The Crust-Atmosphere System, Shuo Ding
Sustainability Seminar Series
Sulfur (S) is one of the most abundant volatiles; one that has a fundamental impact on various magmatic processes, from the mantle to the Earth’s surface. Ocean island basalts (OIB) are one of the critical probes for understanding the chemical, lithological and thermal variations in the Earth’s mantle. Therefore, S abundances of primary OIB that sample peridotite partial melts, as well as deeply recycled components, can provide a better understanding of the long-term S cycle on Earth. In this study, we developed a model to describe the behavior of sulfide and copper (Cu) during decompression melting of the mantle by …
Magmatism And Mass Extinction: Resolving The Flood Basalt Carbon Quandary, Benjamin Black
Magmatism And Mass Extinction: Resolving The Flood Basalt Carbon Quandary, Benjamin Black
Sustainability Seminar Series
Voluminous flood basalt magmatism has coincided with multiple biotic crises, including the end-Permian, end-Triassic, and end-Cretaceous mass extinctions and the Paleocene-Eocene Thermal Maximum. Geochemical evidence shows that warming and carbon cycle perturbation were features of each of these events. This proxy evidence is at odds with current estimates of the budget and isotopic composition of carbon in flood basalt magmas, which suggest that flood basalt magmatic carbon is inadequate and too isotopically heavy to explain the observations. To address the apparent conflict between paleoclimate and petrology, I present results from melt inclusions, carbonatites, geophysical modeling, and climate modeling to address …