I seminari del DiSTAR (2018)
Thilo Bechstädt (Georesources, Heidelberg): “Snowball Earth successions in northern Namibia: Facts and fiction”. 25 Gennaio
Adam Schultz (College of Earth, Ocean & Atmospheric Sciences, Oregon State University): “The 3-D Magnetotelluric Array Revolution. Insights into the role of hydrous and magmatic fluids in continental evolution and natural hazards at convergent margins, along hotspot traces, at the passive margin and in the continental interior”. 9 Marzo (biosketch and abstract)
Sietske Batenburg (Department of Earth Sciences, University of Oxford):““Investigating the role of oceanography in past greenhouse climates using neodymium isotopes”. 27 Marzo (biosketch)
Dr. Adam Schultz
Professor of Geophysics
College of Earth, Ocean & Atmospheric Sciences
Oregon State University
Subsurface Science and Technology Department
Pacific Northwest National Laboratory
Adam Schultz encountered magnetotellurics in 1977 as an undergraduate pursuing a degree in astrophysics at Brown University, in Providence, Rhode Island USA. The random acts of taking a couple of planetary geology classes, and then reading an advertisement for a “geophysical field technician” to participate in a field experiment in the wilds of New Mexico changed his career path (he ended up with an Sc.B. in Geology-Physics-Mathematics) and resulted in more than four decades of playing around with Maxwell’s Equations, coding hundreds of thousands of lines of Fortran (as well as more modern dialects), and building several generations of instruments for magnetotellurics, hydrothermal and other studies. After a post-Sc.B. stint as a marine controlled source electromagnetics (MCSEM) technician at Scripps Institution of Oceanography in La Jolla, California, in 1979 he went on to pursue his Ph.D. in Geophysics at the University of Washington in Seattle, carrying out his Ph.D. work on the variations in electrical conductivity in the mantle on a global scale. Having survived the experience and also Mount Saint Helens’ best attempt to kill him when it erupted in May 1980 while he was carrying out magnetotelluric studies there, in 1986 he was a Cecile and Ida Green Scholar at the Institute of Geophysics and Planetary Physics (IGPP) at the University of California San Diego, working on the rudiments of a 3-D forward solution for EM induction in spherical global coordinates. After five years as a Research Assistant Professor in the School of Oceanography at the University of Washington, where he worked on both induction problems and also seafloor hydrothermal processes, built seafloor and land-based hydrothermal, electromagnetic and seismic instruments and developed methods of analyzing such data, he took up a faculty position at the Institute of Theoretical Geophysics at Cambridge University. After nine years in Cambridge, he took up his Professorship at Cardiff University in Wales where he served as the Head of the School of Earth, Ocean and Planetary Sciences. After family considerations led him to return to the USA in 2003, to Oregon State University, with a two-year sabbatical break in 2006-2008, where he was Program Director for Marine Geology and Geophysics at the US National Science Foundation. Along the path of his global migration, Dr. Schultz has managed to introduce several generations of postdocs, graduate students and undergraduates into the mysteries of applying the governing equations to peer into the Earth’s interior, and some of them have ended up as academics, although others decided to go off and make a ton of money instead.
Lecture, Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse
March 9, 2018
Title: The 3-D Magnetotelluric Array Revolution – Insights into the role of hydrous and magmatic fluids in continental evolution and natural hazards at convergent margins, along hotspot traces, at the passive margin and in the continental interior
Abstract: Substantial advances in 3-D inversion of electromagnetic induction data over the past decade-and-a-half, coupled with sustained support for large-scale 3-D magnetotelluric (MT) array data acquisition efforts have produced a remarkable legacy of MT data and derived data products, and of an emerging canon of 3-D views of crust and mantle electrical conductivity structure. For the past thirteen years, Oregon State University has been the lead institution for the NSF EarthScope MT Program, responsible for acquiring data from approximately 1000 long-period MT stations covering (to-date) on a 70-km interstation grid spanning more than 60% of the territory of the continental USA. Also under NSF EarthScope, MARGINS/GEOPRISMS and US Department of Energy Support, OSU and its collaborators have acquired high-resolution, targeted MT array data along the Cascadia subduction zone margin (both onshore and offshore), in the southern Washington Cascades volcanic arc, at Yellowstone supervolcano, and a 4-D dataset including MT data from an enhanced geothermal stimulation effort at Newberry volcano in central Oregon. We have also acquired a unique, combined MT-ionospheric data set from more than two months of synchronous observations over a wide area in the interior of Alaska. In today’s Lecture, key insights into the role of fluids in the evolution of each of these differing tectonic settings will be presented, drawn from 3-D inverse models produced by researchers from various institutions that are involved in each of these projects. The serendipitous discovery that knowledge of the 3-D electrical structure of the crust and mantle plays an important role in assessing the vulnerability of the electric power grid to the effects of space weather and to risks from electromagnetic pulse (EMP) events will also be introduced.
Dr Sietske J. Batenburg
Post Doctoral Research Associate
§ Integrated stratigraphy
I aim to reconstruct the evolution of ocean circulation in the Cretaceous greenhouse world using Neodymium isotopes as a tracer of water masses. Changes in ocean circulation played an important role in the development and extent of oxygen depletion during the Cenomanian-Turonian transition. Restricted basins responded differently to oceanographic changes than the open ocean and may shed light on regional versus global drivers of oceanic anoxia.
For my current research I will focus particularly on the Western Interior Seaway – a shallow sea which extended across the North American continent and connected the Arctic Ocean to the Gulf of Mexico. I aim to track the development and cessation of regional anoxia which was directly influenced by oceanographic processes.
To identify causes of extreme events, it is essential to obtain tight constraints on the relative timing of climatic processes. On long time scales of up to millions of years, periodic variations in the Earth’s orbit are the main drivers of climate change. For my PhD, I investigated how sedimentary rhythmicity in northern Spain reveals the orbital pacing of Maastrichtian (latest Cretaceous) climate and can provide detailed age control. I use a combination of geochemical and stratigraphic techniques with the aim to understand how small variations in the amount of energy received from the sun influence Earth’s climate and oceanography.