Seds Online Webinars
At Seds Online, we host regular Webinars for the community. Recognising the incredibly broad spectrum of subject matter within our discipline, we aim to provide a structured, balanced, program that covers a range of topics.
Upcoming Webinars & Events
4 PM LONDON, Wednesday 10th June 2020
Sequence stratigraphy of late Paleozoic cyclothems; a signal of sediment undersupply, large-magnitude sea-level changes and low accommodation
Professor Christopher R. Fielding – University of Nebraska-Lincoln
Cyclothems are stratal rhythyms comprising repetitive vertical successions of sandstones, heterolithic (thinly interbedded) sandstones and mudrocks, mudrocks, limestones, and coals, in many cases with pedogenic overprinting of these lithologies. They record repetitive alternations of shallow marine and coastal to nonmarine environments of deposition. They are typical of Carboniferous and Permian paleotropical successions across Euramerica. Controversy endures as to whether cyclothems were formed under external forcing or rather were the product of mainly autogenic processes. Careful mapping and correlation of cyclothem strata and use of a sequence stratigraphic methodology allows a fuller understanding of these enigmatic rhythms. Depositional sequences can be identified and correlated over 100s of km, based on the recognition of regionally extensive disconformity surfaces and the continuity of key marker beds. Erosional surfaces preserve deeply incised valleys, separated by relatively flat interfluves represented by pedogenically modified strata. Sequences bounded by these surfaces are < 2 to > 30 m in thickness, varying considerably in thickness and facies composition but nonetheless preserving predictable arrays of facies that record deepening and shallowing trends. Because of the limited thickness of cyclothems, it is difficult to apply the accommodation succession concept to these deposits. Rather, cyclothem sequences are thin, incomplete, condensed, strongly top-truncated, and have a ragged blanket geometry. Although the term “cyclothem” has been used in a variety of contexts, a definition of the term limited to successions that were deposited (1) on low-gradient pericontinental shelves in paleotropical regions, (2) as far-field products of Gondwanan glacial growth and decay at various timescales, and (3) under conditions of low sediment supply in most cases, and (4) under low accommodation limited by slow, passive subsidence is herein preferred.
4 PM LONDON, Wednesday 17th June 2020
Observing turbidity currents in the wild: New insights from direct field-scale measurements
Dr Mike Clare – National Oceanography Centre
Avalanches of sediment in the ocean, called turbidity currents, are among the volumetrically most important sediment transport processes globally. Due to their fast speeds, turbidity currents can break critical infrastructure, and transport organic carbon and nutrients far into the deep-sea, thus sustaining deep-sea ecosystems. Until recently, we have largely had to rely on the deposits that they left behind or small-scale flows held ‘captive’ in the laboratory to understand turbidity currents. New developments in technology now enable detailed and direct measurements of powerful flows at field scale to complement these studies. Here, we present recent measurements gathered by a large consortium of researchers from a range of shallow to deep-marine settings worldwide that provide new insights into the internal anatomy of these these flows, how they initiate, evolve and interact with the seafloor.
4 PM LONDON, Wednesday 24th June 2020
How to Survive a Review
Your project is completed. The results are in and the outcomes are, frankly, fantastic! It’s now time to share your research with the wider community – it’s time to publish. Writing your first manuscripts for publication can be a daunting task.
• How do I select an appropriate journal for my topic?
• How should I organise the manuscript?
• How long should it be?
• What are the key elements that the editors are going to look for?
• What can I do to increase visibility on search pages?
• I am not confident whilst writing in English – is there any help?
• These are just some of the plethora of questions raised by new authors.
4 PM LONDON, Wednesday 8th July
An introduction to OSL Dating and luminescence signals
Dr Gloria I. López
National Research Centre on Human Evolution (CENIEH) Recanati Institute of Maritime Studies (RIIMS) at the University of Haifa, Israel
“To see the World in a grain of sand… hold infinity in the palm of your hand and eternity in an hour” might be one of the best poetic descriptions for Luminescence Dating… sure, back in 1803, William Blake could not have imagined such scientific achievement! As a matter of fact, Optical Dating or OSL (Optically Stimulated Luminescence) has been one of the fastest growing dating methods since its development in 1985, in terms of protocol development, instrumentation and use. Who would have thought that a single ray of sunshine and the natural radioactive decay ever present in the environment would be allies for OSL signals to shine! As it uses two of the most abundant mineral grains available on the surface of the Earth (quartz & feldspars), OSL has a multitude of applications in addition to the ability to assign numerical ages to numerous environments and sedimentary deposits from the depths of the ocean to the highest peaks. In this presentation we will go over the basics of OSL Dating, and consider some of the major challenges, as well as the advantages. We will have a glimpse at the latest developments and applications, with a special focus on sedimentological and stratigraphical issues. One thing to bear in mind: OSL might not be used only for dating! The in-depth analysis of luminescence signals may give unforeseen insights into transport-deposition processes and events of both natural and anthropogenic origin.
4 PM LONDON, Wednesday 15th July 2020
Deep water sediment deposition from hybrid contour-turbidity currents; first process models for mixed depositional systems based on laboratory experiments.
Dr. Joris T. Eggenhuisen (speaker), E. Miramontes, R. Silva Jacinto, J. Hernández-Molina, F. Pohl, G. Poneti, and collaborators.
Two types of currents dominate sediment transport and deposition on continental slopes: sediment gravity flows that travel down the slope through submarine canyons, channels, and gullies; and bottom currents that are part of the ocean circulation and commonly flow along the slope. Continental slope morphologies reported from mixed sediment gravity flow – bottom current systems across the planet reflect various degrees of interaction between sediment gravity flows and bottom currents. Unfortunately, two communities of researchers have historically specialized in either gravity driven sediment transport or bottom current sediment transport. Consequently, the processes governing sediment transport and deposition in mixed systems are not clearly established and interpretations of mixed-system deposits in literature remain hypothetical and sometimes appear contradictory. In this seminar we will present the first measurements of combined contour-current and turbidity-current flows, which were obtained in laboratory experiments. The measurements demonstrate that contour currents flowing at 10 % of the turbidity current speed can pervasively deflect the turbidity current flow and prove for the first time that hybrid bottom-turbidity currents can be at the origin of asymmetric channel-levee systems. These first experiments are the starting point for discussions on the themes that need to be addressed by the deep water community to achieve an integrated understanding of sediment deposition in deep water environments by contour currents and turbidity currents.
Wednesday 26th August 2020
Conference: ‘Sedimentology in the Anthropocene’
Details coming soon…