To post an event in the JSG Events calendar, send details (talk title, series, date, start and end time, location, contact) to the representative for the unit hosting the talk:
Bureau of Economic Geology: Valerie Siewert
Department of Geological Sciences: Lyndsey Turner
Institute for Geophysics: Nancy Hard
Dean’s Office/CIEEP/EER/Other: Submit a ticket
Click to watch online.
Speaker: Pascal Audet, University of Ottawa
Host: Thorsten Becker
Title: Resolving plate structure across the seismogenic to slow-slip zone in Cascadia from onshore-offshore receiver function imaging
Abstract: Studies of the forearc structure in the Cascadia subduction zone using receiver functions have resolved structures associated with deep fluid cycling, such as the basalt-to-eclogite reaction and fluid overpressure within the subducting oceanic crust, as well as the serpentinization of the forearc mantle wedge. Unfortunately, the updip extent of the over-pressured zone, and its possible control on the transition from episodic slow slip to seismic slip, occurs offshore and is not resolved in those studies. The Cascadia Initiative (CI) has provided an opportunity to extend this work to the locked zone using teleseismic receiver functions from the deployment of a dense line of ocean-bottom seismograph stations offshore of Washington State, from the trench to the coastline. Here we calculate P-wave receiver functions using data from offshore (CI) and onshore (CAFE) broadband seismic stations. These data clearly show the various scattered phases associated with a dipping low-velocity layer that was identified in previous studies as the downgoing oceanic crust. These signals are difficult to untangle offshore because they arrive at similar times. We process receiver functions using a modified common-conversion point (CCP) stacking technique that uses a coherency filter to optimally stack images obtained from the three main scattered phases. The resulting image shows along-dip variations in the character of the seismic discontinuities associated with the top and bottom of the low-velocity layer. Combined with focal depth information of regular and low-frequency earthquakes, these variations may reflect changes in the material properties of the megathrust across the seismogenic zone in Cascadia.
Laura Rodriguez,
The Pennsylvania State University
Thesis: "The Chemistry of Nitrogen Heterocycles in Complex Prebiotic Mixtures: Using Chemical Trends to Elucidate Plausible Pre-RNAs on the Early Earth."
Advisor: Dr. Christopher House
Vashan Wright
Southern Methodist University
Dissertation: "Assessing Quaternary Geohazards in Hispaniola and Jamaica using Seismic, Remote Sensing and Sediment Core Data."
Advisor: Dr. Matthew Hornbach
Carmen Atkins
University of Alabama,
Thesis: "Geochemical, Spatial, and Seismic Characterization of Microbialite Reservoir Distribution on Carbonate Ramps: A Comparison between the Jurassic Smackover and the Cambrian Wilberns Formations."
Advisor: Dr. Marcello Minzoni
Melissa Sims
The State University of New York at StonyBrook
Simulating Meteor Impacts in the Diamond Anvil Cell'
Advisors: Dr. Timothy Glotch and Dr. Matthew L. Whitaker
Informal weekly presentations by UTIG students and researchers. Bring your lunch!
Speaker: Ian Dalziel, Research Professor, UTIG
Click to watch online.
Speaker: Sarah Hörst, Johns Hopkins University
Host: Krista Soderlund
Title: Planets in a Bottle: Exploring Planetary Atmospheres in a Lab
Abstract: From exoplanets, with their surprising lack of spectral features, to Titan and its characteristic haze layer, numerous planetary atmospheres may possess photochemically produced particles of "haze". With few exceptions, we lack strong observational constraints (in situ or remote sensing) on the size, shape, density, and composition of these particles. Photochemical models, which can generally explain the observed abundances of smaller, gas phase molecules, are not well suited for investigations of much larger, solid phase particles. Laboratory investigations of haze formation in planetary atmospheres therefore play a key role in improving our understanding of the formation and composition of haze particles. I will discuss a series of experiments aimed at improving our understanding of the physical and chemical properties of planetary atmospheric hazes on Titan, Pluto, super-Earths, and mini-Neptunes.
56 years after the publication of Rachel Carson’s groundbreaking book, “Silent Spring”, we still face major impacts on our environment and our health from pesticides. Join us as one of the nation’s leading experts on the effects of agricultural chemicals on hormones, Dr. Tyrone Hayes, shares his research and unique experience as an investigative scientist.
Informal weekly presentations by UTIG students and researchers. Bring your lunch!
Speaker: Brandon Shuck, Graduate Research Assistant, UTIG
Click to watch online.
Speaker: Alexander Evans, Brown University
Host: Krista Soderlund
Title: The First Billion Years of Lunar Evolution: A Geophysical Perspective
Abstract: Although several aspects surrounding the early evolution of our Solar System remain shrouded in mystery, the Moon has recorded on its well-preserved and ancient surface much of the history of our Solar System. With accessibility and data returned from orbital and landed spacecraft, the Moon has a unique role in understanding and constraining the evolution of the planets in our Solar System, as well as the timing of its many major events. In this talk, I attempt to unravel some of the mysteries of the Moon from its surface down to its core, to reveal a new understanding of the Moon, the Earth, and the Solar System.
Informal weekly presentations by UTIG students and researchers. Bring your lunch!
This week: Dennis Tong presents his PhD defense talk!
Speaker: Dennis Tong, Graduate Research Assistant, UTIG
Click to watch online.
Speaker: Rosie Oakes, Drexel University
Host: Chris Lowery
