Lecture series – u.s. science support program electricity experiments elementary school


Plants – from lush rainforests to desert shrublands – map climatic differences on the landscape. The waxy molecules coating plant leaves are some of the most resilient biochemicals made by plants and they contribute to the sedimentary legacy of past environment, archived in deep sea sediments. The International Ocean Discovery Program has recently drilled the two largest submarine fans in the world, the Bengal Fan (Expedition 354) and Indus Fan (Expedition 355). These megafans yield thick deposits of dominantly terrestrial organic matter derived from the Ganges-Brahmaputra and Indus River systems respectively. In addition, legacy cores from the Gulf of Aden (Expedition 24) contain wind-blown terrestrial organic material from NE Africa. From each of these expeditions we have uncovered a record of landscape change and I weave these together with terrestrial evidence into an integrated story of landscape and climate change around the shores of the Indian Ocean. Plant waxes are key to this story as their C isotopic composition reflects photosynthetic pathway and their H isotopic composition that of precipitation. Dual analyses in the same plant wax molecules allow climate and ecology to be tracked in tandem. Using this approach, we find unequivocal evidence that drying in the core monsoon region coincided with the widespread development of C4 grasslands. These plant wax records provide dramatic illustration of the sensitivity of ecosystems to climatic change in one of the most flood and drought prone, and highly populous, regions of the globe.

Dr. gas hydrates wiki Feakins is an Associate Professor of Earth Sciences at the University of Southern California. She received her Ph.D. from Columbia University and was a NOAA Postdoctoral Fellow at Caltech. Sarah has worked on deep sea drilling cores for the past 15 years. A graduate student and a postdoctoral researcher from her group sailed as shipboard scientists on two consecutive IODP Expeditions (Expeditions 354 and 355).

Monsoonal regions in Asia are natural laboratories for studying the interplay between tectonics, climate and the biosphere. At human time scales, monsoon rains are critical to the well-being of billions of people. Scientific drilling has been crucial in uncovering the history of the monsoon. Dr. Giosan will review past milestones in monsoon research: from the potential role of Himalaya-Tibet uplift on establishing the monsoon and proposed feedbacks with mountain building via erosion to the effect of monsoon rain variability on ancient civilizations. The review will address long-running dilemmas and conflicting interpretations such as the potential decoupling of monsoon winds from monsoon rains and the role of Cenozoic global cooling in modulating the monsoon vs. the role of monsoon erosion and weathering in establishing the late Cenozoic “Icehouse.”

Recently the International Ocean Discovery Program drilled in the Indian and Pacific Oceans and objectives of multiple expeditions were designed to solve monsoon quandaries. Using past and novel multiproxy reconstructions, Dr. electricity vs magnetism Giosan will present the concept of a monsoon erosional pump modulated by topography and land cover to reconcile conflicting interpretations, reassess the history of the monsoon, and estimate potential effects on elemental cycles during the Cenozoic. Under this new framework, the monsoon exhibits two distinct flavors that can be largely explained by its heartbeat, or astronomical forcing, mediated by the global glacial state and the paleogeography of South Asia. Finally, Dr. Giosan will discuss how this new understanding of the monsoon helps us explore the past civilizations of Asia with their periods of flourishing or collapse and the lessons that these hold for us in the Anthropocene.

Dr. Giosan is a tenured Associate Scientist at the Woods Hole Oceanographic Institution on Cape Cod, Massachusetts. He has spent more than a year at sea on national and international research expeditions, including four ODP/IODP expeditions, and has been involved in a number of onshore field programs in Romania, Bulgaria, Spain, Pakistan, India, Myanmar, Botswana, Alaska and Arctic Canada.

IODP drilling of marine sediments around southern Africa during Expedition 361 offers exciting opportunities to elucidate the long-term role of the Agulhas Current System in ocean circulation and southern African climate variability through the past 5 (as much as 7) million years. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. electricity in salt water experiment Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data suggest that the Agulhas Current may be a factor in the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Expedition 361 obtained records that will allow documenting paleoclimate and paleoceanography of this region. The main objectives of the expedition were to establish the sensitivity of the Agulhas Current to climatic changes during the Pliocene–Pleistocene, to determine the dynamics of the Indian-Atlantic gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution.

Fine-grained sediments such as mudstones are the most common sedimentary rocks preserved close to Earth’s surface. Mudstones are very susceptible to developing significant amounts of overpressure because their low permeability and high compressibility prevent pore fluids from draining. This can result in seepage, submarine landslides, or damage to offshore infrastructure. Additionally, mudrocks are fundamentally important as source, seal, and shale gas/oil reservoirs in petroleum systems or as seals for anthropogenic-related storage. In spite of the importance of mudstones to significant hazards and industry endeavors, a systematic, process-based understanding of the controls on hydromechanical properties in mudstones remains elusive. To study these questions Dr. Reece fabricates mudstones in her laboratory from natural, marine sediments, acquired through the International Ocean Discovery Program and its predecessors, using a technique called resedimentation. Resedimentation simulates the natural process of deposition and shallow burial under controlled conditions, is repeatable, and eliminates the problem of coring disturbance associated with testing on intact cores. Therefore, resedimentation is an ideal method for the study of fundamental mechanical behavior of marine sediments. In combination with microscale imaging techniques it also reveals how porosity, permeability, and fabric evolve with burial. Dr. Reece particularly focuses on the interactions between fine-grained detrital particles, microorganisms, microfossils, and pore fluid and their roles in early diagenesis. Here, Dr. Reece will present results from investigations of early chemical and physical diagenesis using mudstones from the Gulf of Mexico (IODP Expedition 308) and offshore Japan (IODP Expedition 322).

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. electricity deregulation choices and challenges Overall patterns and functioning of modern oceanic circulation is relatively well understood, but significant uncertainty remains about circulation in the geologic past and during different climate regimes. 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. shale gas in spanish Romans will present research from the North Atlantic Ocean (Expedition 342, Newfoundland Drifts) that shows how vast deep-sea “drift” deposits relate to the onset of and changes in ocean circulation in the Eocene through Miocene. In addition to his work on the North Atlantic, Dr. Romans will also present preliminary findings from new drilling (January-February 2018) in the Ross Sea (Expedition 374, West Antarctic Ice Sheet History), which aims to study interactions of Southern Ocean circulation and Antarctic ice sheet dynamics during significant climate events of the Miocene and Pliocene.

Dr. Romans is an associate professor in the Department of Geosciences at Virginia Tech. He received his Ph.D. in Geological & Environmental Sciences from Stanford University, M.S. in Geology & Geological Engineering, and undergraduate degree in Geology at SUNY Buffalo. Brian participated as a shipboard scientist on two IODP Expeditions (Expeditions 342 and 374).

The transfer of material and energy between Earth’s ocean and lithosphere plays an important role in regulating climate and in the geochemical evolution of the ocean, crust, and mantle. The evolution of seawater composition is intimately linked to changes in the magnitude of element sources and sinks through geologic time. The modern chemical fluxes associated with river input and high-temperature hydrothermal circulation are well-constrained in comparison to the diffusive exchange between marine sediments and the ocean. Chemical reactions in marine sediments, however, play an important role in the marine biogeochemical cycles of many elements, as indicated by positive and negative gradients in their concentration in sediment pore water. These gradients are driven by seafloor and subseafloor diagenetic reactions such as microbial oxidation of organic carbon, methanogenesis and methane oxidation, authigenic carbonate and aluminosilicate mineral precipitation, ion exchange, and carbonate dissolution and recrystallization. Detailed studies of these reactions and associated chemical fluxes are often from only a few sites, making it difficult to extrapolate these fluxes globally. There has been a significant momentum over the past decade to constrain the global flux of elements and isotope ratios to/from marine sediments, motivated by the large pore water chemistry dataset acquired through scientific ocean drilling.

The large ocean drilling dataset collected over the past ~50 years covers a wide-variety of environments including abyssal ocean basins, convergent and divergent margins, back-arc basins, and a wide-range of areas with differing sedimentation rates, organic carbon burial, and sediment types. This characteristic diversity of the dataset lends itself well to reactive-transport modeling and modern machine-learning statistical techniques to constrain global element fluxes between the ocean and marine sediments. In this talk, I will present recent results from my research group and the broader marine geochemistry community using the ocean drilling dataset to evaluate diagenetic reactions occurring in continental margin sediments and the role of marine sediments in the oceanic cycles of a range of solutes and isotope ratios including Mg, d 26Mg, Ca, alkalinity, and Si. These new estimates provide a solid benchmark for the modern marine sediment source/sink and for exploring how the processes controlling seawater composition change throughout Earth’s history.

Dr. Solomon is a marine geochemist/geologist who studies the transfer of water, solutes, isotope ratios, and carbon between the ocean and lithosphere. 5 gases Most recently, his research has focused on sediment diagenesis, subduction zone hydrogeology, cold seep dynamics, and the development and deployment of seafloor/subseafloor hydrologic observatories. Dr. Solomon has sailed on six ODP/IODP expeditions, including upcoming IODP Expedition 375 at the Hikurangi subuction zone, offshore New Zealand.