Geology Open Night

One hour toward professional development is available for teachers and professional geologists attending the Geology Open Night lectures.

Uncommon behavior of a common mineral lends new insight into the  ancient lunar crust     Hanna Nekvasil   7:30  PM Friday  January 29, 2016 ESS 001 Our interpretation of lunar history is strongly intertwined with the model of a lunar magma ocean in which plagioclase began crystallizing late and floated and accumulated to form an anorthositic crust. However, to date, the search continues for direct evidence of a deep origin of minerals that make up the anorthosite that could validate this fundamental model. Such evidence has been elusive as laboratory investigation of nominally equivalent terrestrial minerals has shown that these minerals do not change their crystallization behavior over the pressure range of the lunar magma ocean and therefore, are poor indicators of pressure. With new investigation of a long standing enigma regarding the compositional invariance of plagioclase in lunar anorthosite, we have shown that plagioclase of the highly calcic composition of the lunar anorthosite is not only sensitive to pressure but shows evidence for a high pressure origin. This provides the first diagnostic means of assessing the possibility of a lunar magma ocean source of the Highlands anorthosite. Hanna Nekvasil is a Professor in the Department of Geosciences at Stony Brook University. She received her B.A from Cornell University in 1979 and her Ph.D. from Penn State in 1985. She has been a professor in the Department of Geosciences at Stony Brook since 1988, where she has focused on understanding the igneous history of the Earth, Moon, and Mars primarily through simulating, in the laboratory, the conditions of crystallization on these planetary bodies.  Recently, her group was the first to identify a mineral on the Moon that contained water and showed that the Moon was not as dry as first thought. Today she will report on their new results that provide the first definitive criteria to assess whether a lunar magma ocean actually existed in the Moon’s past.

A Rover’s Eye View of the  Ancient Surface and Climate of Mars Joel Hurowitz 7:30 PM Friday February 19, 2016 ESS 001 For nearly a decade, the international program of Mars exploration has been guided by a remarkably useful framework that describes how Mars’ environmental conditions have evolved in the context of time-dependent changes in the composition of rock and soil deposits at the Martian surface. Built on the basis of observations by the instruments onboard the European Space Agency’s Mars Express Orbiter, this framework describes an early era of Earth-like surface environments that gave way to a far more arid environment in which surface water was acidic and salt-rich. Ongoing observations by Mars Express and the higher-resolution instruments onboard NASA’s Mars Reconnaissance Orbiter have continued to refine and extend this paradigm, but as is the case on Earth, the greatest insight into the evolution of surface environments comes from close-up examination of the sedimentary rock record. In-situ observations of sedimentary rocks by NASA’s Opportunity and Curiosity rovers enable evaluation of hypotheses developed from orbit, and reveal that interactions between iron-rich waters and the atmosphere have played a critical role in the evolution of the Martian surface. I will discuss observations of the sedimentary rock record by NASA surface missions to Mars, drawing parallels between ancient Mars and processes inferred from ancient sedimentary rocks on Earth. I will also discuss the upcoming Mars 2020 rover mission and the role that the Planetary Instrument X-ray Lithochemistry (PIXL), part of the scientific payload for this mission, will play in further deciphering the geochemical history of the surface of Mars. Joel Hurowitz, an assistant Professor in the Department of Geosciences, is a geochemist and planetary scientist working at the forefront of the exploration of Mars and the Solar System. Specializing in understanding the processes of sedimentary rock formation and evolution, Prof. Hurowitz has worked extensively on the ongoing Mars Exploration Rover mission, launched in 2003, and the more recent Mars Science Laboratory (MSL) rover mission, which was launched in 2012. He has played a variety of roles on these missions from scientist, to rover instrument design and operations specialist, to science and engineering operations team leader. Prof. Hurowitz is the Deputy Principal Investigator of one of the 7 instruments recently selected for the science payload of the Mars 2020 Rover mission, which is expected to operate on Mars at least through the year 2023. This instrument, called “PIXL”, for “Planetary Instrument for X-ray Lithochemistry”, is a micro-focus X-ray fluorescence instrument that will produce high-fidelity maps of the distribution and abundance of chemical elements within rocks and soils at the Mars 2020 rover landing site. He has previously held positions at the NASA Jet Propulsion Laboratory (JPL, 2007-2013),and the California Institute of Technology (Caltech, 2006-2007).

How Seismic Wave Speeds are Affected by Partial Melting Donald Weidner 7:30 PM Friday March 25, 2016 ESS 001 Seismic waves thoroughly sample the Earth’s interior.  By extracting the speed that these waves travel, we recover information about the material at that place in the Earth.  Our ability to infer further information about such a region relies on our understanding how the possible characteristics of that region such as chemical composition or crystal structure affect these sound speeds.  One important issue that requires such understanding is how does partial melting affect these sound speeds?  Using synchrotron based high pressure research and thermodynamic models, we feel that we have uncovered a new twist on this half – century old question.  We postulate that the melting itself interacts with the seismic wave to slow it down.  In the talk we will revisit some of the experimental and thermodynamics that has led to this conclusion. Dr. Weidner received his undergraduate education from Harvard University and PhD from Massachusetts Institute of Technology.  He is a SUNY Distinguished Professor in the Department of Geosciences where he has been a faculty member for over 40 years.  He is currently Director of the Mineral Physics Institute. Dr. Weidner’s research focuses on understanding the deep Earth by understanding the rocks and minerals that make up this inaccessible region. He has developed several new experimental tools to this end.  He currently is involved in synchrotron research on samples at high pressure and temperature.  His group runs a beamline at the Advanced Light Source in Argonne National Laboratory near Chicago and is building one at the National Synchrotron Light Source II at Brookhaven National Laboratory.  He is winner of two international awards; the James B. Macelwane award of the American Geophysical Union in 1981 “For significant contributions to the geophysical sciences by an outstanding early career scientist” and the Inga Lehmann award, also of the American Geophysical Union in 2011 “For outstanding contributions to the understanding of the structure, composition, and dynamics of the Earth’s mantle and core”.

North Korea’s Nuclear Tests: what we learned from  seismology Lianxing Wen 7:30 PM Friday April 29, 2016 ESS 001 In 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty, which bans nuclear explosions by everyone, everywhere: on the Earth's surface, in the atmosphere, underwater and underground. So far, 183 countries have signed the Treaty, of which 164 have also ratified it. Seismology plays one of the most prominent roles in monitoring nuclear tests around the world. In recent years, we have been developing seismological methods to detect low-yield nuclear tests and to determine the location and yield of a nuclear test in high precision. In this presentation, I will present high-precision locations and yields of North Korea’s 2006, 2009, 2013 and 2016 nuclear tests, and seismic evidence for a low-yield nuclear test conducted by North Korea in May 2010. Professor Wen is a theoretical and observational seismologist and geodynamicist. His research is directed toward understanding the structure, dynamics, composition and evolution of the Earth and other planets. He uses seismic waves to probe the internal structure of the Earth and its change with time, combines seismic and mineral physics data to constrain the composition of the mantle, and develops geodynamical models of how Earth's internal processes govern the Earth's continental drift, surface uplift, surface large igneous province, geochemistry, intra-plate deformation and volcanism.  Professor Wen is a recipient of the James B. Macelwane Medal from the American Geophysical Union (AGU) and a fellow of the Union. Macelwane Medal honors “significant contributions to the geophysical sciences by a young scientist of outstanding ability” and AGU fellowship is a designation conferred upon not more than 0.1% of all AGU members in any given year.

 

You may also be interested in the following lectures: Astronomy Open Night, The World of Physics and The Living World These lectures are usually held in ESS 001 at 7:30 p.m. on Fridays during the academic year. Professional Development letters are available for teachers and geologists for attending these lectures.