NATHAN J. MCGREGOR

Ph.D. Student in Planetary Science
University of California, Santa Cruz

Cosmochemistry

about // research // publications & presentations // dei // teaching // contact // cv



About

I am a second-year Ph.D. student in Planetary Science at the University of California, Santa Cruz and a member of the UCSC Planetary Science Group studying the evolution of bodies in the solar system by pairing experiments with thermal models. My advisors are Professors Francis Nimmo and Myriam Telus.

I am interested in (1) how thermal evolution depends on body size, (2) how does volatile loss and retention happen and how does it affect geodynamics, and (3) what processes heated and altered meteorite parent bodies.

I received my B.S. in Physics and Astrophysics and B.A. in Political Science from Boise State University. During my undergraduate career, I worked with Professor Daryl Macomb on long-term optical monitoring of BL Lacertae objects and was a member of Professor Brian Jackson’s Planetary Science Research Group.


Research

Venus

Baltis Vallis (BV) is a lava channel on Venus that flows uphill. Since lava flows downhill, BV must have been deformed after emplacement. Thus, it possesses a record of Venus’ convective history, as mantle convection causes time-dependent surface topography deformation. There is short-wavelength deformation of 300 km due to faulting, and long-wavelength deformation of 2000 km. This 2000-km length scale is comparable to the thickness of the Venusian mantle, strongly suggesting that mantle convection is responsible for the observed deformation. Since the surface age of Venus is 500 million years, BV tells us that convection on Venus has been active at least over the same timescale and provides information on the length scales and vertical amplitudes involved. My goal is to place constraints on Venus’ present-day internal structure and dynamics (e.g. viscosity) by using models of mantle convection. I aim to answer the following: What convection regime is most consistent with observations of the surface deformation of Venus?

Unfiltered and filtered topographic profile of BV. A and A′ mark the source and termination points, respectively. Short wavelengths are removed to show the long-wavelength deformation caused by convection.
Median decorrelation time and RMS of each model colored by Ra. BV’s RMS (315 m) is plotted as a vertical line. Venus’ approximate surface age (500 Myr) is plotted as a horizontal line. The shaded region repre- sents the range of estimates for Venus’ surface age (150- 800 Myr). Error bars are interquartile ranges. The most promising models (VL3 and L3) plot close to BV’s RMS and have decorrelation times less than 500 Myr.

Publications & Abstracts

  • McGregor, N. J., Nimmo, F., Gillmann, C., Golabek, G., Plattner, A. & Conrad, J. W. (2023). Constraining Venus’ Convection Regime from Baltis Vallis Topography. European Geosciences Union General Assembly.
  • McGregor, N. J., Nimmo, F., Gillmann, C., Golabek, G., Plattner, A. & Conrad, J. W. (2023). Constraining Venus’ Convection Regime from Baltis Vallis Topography. Lunar and Planetary Science Conference.
  • Calderon, T., Jorge-Chavez, F., McGregor, N. J., & Telus, M. (2022). Investigating Mn Rims of Chondrule Meteorites. UC Santa Cruz Research Experiences for Undergraduates Program on Sustainable Materials.
  • McGregor, N. J. & Macomb, D. (2020). Photometric Monitoring of MRK 501: A Model for Measuring the Optical Variability of BL Lacs. Idaho Conference on Undergraduate Research, #131.
  • McGregor, N. J. & Macomb, D. (2020). Photometric Monitoring of MRK 501: A Model for Measuring the Optical Variability of BL Lacs. Boise State University Research Showcase, #119.
  • McGregor, N. J. & Macomb, D. (2012). Identifying X-Ray Sources in Local Group Galaxies Using Fourier Analysis of Time Series Data. Boise State University Undergraduate Research and Scholarship Conference, #22.

DEI & Outreach

I have a strong track record of improving access and opportunity for all by engaging with communities that are underrepresented in STEM, working with students from diverse backgrounds, and participating in community service efforts. I am currently the Graduate Student Representative on the Committee on Affirmative Action and Diversity (CAAD) with the UCSC Academic Senate and a member of two diversity, equity, and inclusion (DEI) groups: a graduate-led group and a Department committee comprising faculty, staff, and a few students.

LGBTQ DEI in science is a deeply personal passion of mine, as I have experienced the feeling of not belonging as an LGBTQ scientist. I strive to help middle school, high school, and university students see a future for themselves in science, and feel welcome and free of discrimination in their respective disciplines, particularly those who identify as LGBTQ. Currently, I volunteer several hours per week with the Queer Youth Task Force of Santa Cruz and Safe Schools Project of Santa Cruz County. I work with local K-12 schools and students to encourage and promote their interest in STEM, particularly among underrepresented minorities who are better able to imagine themselves as scientists once they see it is possible. Working with youth is especially rewarding, as their passion and curiosity is invigorating. Helping them see there is a place for them in science where they are celebrated and welcomed instills them with confidence that motivates them for years to come. I continue to develop solutions for challenges faced by LGBTQ scientists and youth, and to make science safer and more inclusive for all.


Teaching

Teaching Assistant, University of California, Santa Cruz
  • EART 111, Mathematics in the Earth Sciences, Fall 2022
Lab Instructor, Boise State University
  • PHYS 212L, Physics II with Calculus, Summer 2021
  • PHYS 105, Stars and Cosmology, Spring 2021 (2 sections)
  • PHYS 101, Introduction to Physics, Fall 2020
  • PHYS 111, General Physics I, Summer 2020
  • PHYS 111, General Physics I, Spring 2020
  • PHYS 112, General Physics II, Fall 2019
Teaching Assistant, Boise State University
  • PHYS 341, Classical Mechanics, Spring 2021
  • PHYS 111, General Physics I, Spring 2020
  • PHYS 111, General Physics I, Fall 2019
  • MATH 170, Calculus I, Fall 2013
  • MATH 175, Calculus II, Summer 2012
  • MATH 170, Calculus I, Spring 2012
  • MATH 170, Calculus I, Fall 2011

Contact

University of California, Santa Cruz
Earth and Planetary Sciences
1156 High Street
Santa Cruz, CA 95064
njmcgreg@ucsc.edu