Stanford Doerr School of Sustainability


Showing 41-50 of 142 Results

  • Tianyang Guo (郭天阳)

    Tianyang Guo (郭天阳)

    Postdoctoral Scholar, Geological Sciences

    BioDr. Tianyang Guo earned his Ph.D. degree in Rock Mechanics from the Department of Earth Sciences, the University of Hong Kong in 2020. He earned his bachelor's and master’s degree from Wuhan University (WHU) in 2013 and 2016, respectively. He was awarded the National Scholarship for Graduate in 2015 and graduated from WHU as an outstanding graduate. Before joining Stanford, he was a Postdoctoral Fellow in the Department of Civil and Environmental Engineering at the Hong Kong Polytechnic University (PolyU) under PolyU Distinguished Postdoctoral Fellowship Scheme 2021.

    His research interests include (1) Cracking mechanisms and induced microseismicity during the injection of CO2 into reservoir rocks. (2) Application of machine learning in acoustic emission (AE) data interpretation. (3) Microcracking mechanisms of granite based on AE and microscopic observation.

  • Susannah Herz

    Susannah Herz

    Ph.D. Student in Earth and Planetary Sciences, admitted Autumn 2023
    Masters Student in Earth and Planetary Sciences, admitted Spring 2026

    Current Research and Scholarly InterestsI am interested in investigating the impacts of ocean anoxia through the end Permian mass extinction. My work utilizes a variety of isotope geochemistry techniques, including investigations of the sulfur, calcium, and thallium systems through both modeling and lab-based approaches.

  • Michelle Hill

    Michelle Hill

    Postdoctoral Scholar, Earth and Planetary Sciences

    BioMichelle's work addresses a fundamental question in exoplanet habitability: determining the minimum planetary size required to maintain an atmosphere, a critical prerequisite for life as we know it. She found that stagnant lid (no plate tectonics) planets Earth sized and below orbiting in the habitable zone (HZ) of a Sun-like star need to be ≥ 0.8 Earth radii to maintain their atmosphere past 1 billion years. As a Stanford Science Fellow, Michelle will advance her research and expand her planetary habitability models to look at how tectonic regime, initial volatile content, stellar type, tidal locking and tidal heating effect the results of whether a planet smaller than Earth can hold onto it's atmosphere. Her faculty host is Laura Schaefer, Assistant Professor in the department of Earth and Planetary Sciences.

    Michelle also detects and refines the masses and orbits of exoplanets using a combination of radial velocity (RV), transit and astrometry. She is currently observing 10 known planet systems that have shown indications of additional planets in orbit in order to detect the long period outer companions. These observations have lead to the discovery of 3 planets so far.


    Michelle recently completed her PhD in Earth and planetary sciences at the University of California, Riverside, where she developed research on exoplanet habitability while supported by the NASA FINESST award. She lead a catalog paper on the demographics of all the known planets in HZ of their star where she found evidence of the sub-Saturn valley in the HZ. During this time she was also a member of the TESS-Keck Survey (TKS) team that conducted RV followup of TESS Objects of Interest (TOIs) and she lead the discovery paper of TOI-1386 b and c.

    Michelle completed her post bachelor honours in astrophysics at University of Southern Queensland, Australia. Here Michelle worked on the occurrence rates of giant exoplanets in the habitable zone of their star and found that while giant planets are less likely to be found in the habitable zone than terrestrial planets, if each giant planet is host to more than one moon then exomoons could be more numerous than terrestrial planets in the habitable zone of their star. This work has direct implications for the fraction of stars in the galaxy that may host habitable terrestrial worlds.

    Prior to this Michelle completed her bachelors in physics at University of New England, Australia where she attended San Francisco State University during her year abroad. Here she contributed to a study of the Kepler habitable zone planets where she found that the distribution of planets within the habitable zone closely mirrored the distribution of all known planets. This discovery had major implications for the opportunities of statistical analysis of this relatively small group of habitable zone planets.


    Michelle loves flying! She was a commercial pilot before returning to school to study physics. She currently holds an Australian ATPL with plans to (one day!) convert this to an FAA APT.

  • George Hilley

    George Hilley

    Professor of Earth and Planetary Sciences

    Current Research and Scholarly InterestsActive tectonics, quantitative structural geology and geomorphology; Geographic Information Systems;unsaturated zone gas transport; landscape development;active deformation and mountain belt growth in central Asia, central Andes, and along the San Andreas Fault; integrated investigation of earthquake hazards.