skip to main content
Caltech
Division of Geological and Planetary Sciences

Joann M. Stock

Home  /  People  /  Joann M. Stock

Joann M. Stock

Professor of Geology and Geophysics
B.S., Massachusetts Institute of Technology, 1981; M.S., 1981; Ph.D., 1988. Visiting Assistant Professor, Caltech, 1990; Associate Professor, 1992-98; Professor, 1998-.
Research Summary
Plate tectonics; structural geology; evolution of plate boundaries; stress and deformation in the lithosphere; physical volcanology; tectonics and regional structure of the Pacific-North America and Pacific-Australia plate boundaries; active volcanism and CO2 emissions; tectonics of Venus.

Research Options

Geology;  Geophysics; 

Research Areas

Marine Geophysics;  Seismology;  Tectonics; 

Profile

Ongoing Research in Tectonics

Joann Stock's research interests involve a wide range of tectonic problems, including global and regional plate tectonic questions, and geological and geophysical field studies related to plate boundary evolution.

Recent Ocean Drilling Projects

I sailed as a structural geologist on IODP Expedition 385 to the Guaymas Basin, Gulf of California (mid September to mid November 2019). We drilled numerous holes in young sediments for tectonics and geobiology studies. I am collaborating with other US and Mexican scientists on the correlation of ash layers and the core-log-seismic integration.

I sailed as co-chief scientist on IODP Expedition 367 to the South China Sea Rifted Margin (Feb. 9 to April 9, 2017). This was a two-expedition project, followed by Expedition 368 for the 2nd half of the work now. Due to mechanical problems during Expedition 368, one of the drill holes was drilled this Nov.-Dec. 2018, to finish the data acquisition for the project. The recent publication with highlights of the results is Larsen et al., 2018.

Another Recent Marine Geophysics Project

I sailed on Marcus G. Langseth cruise 1803 in Feb. and March 2018, south of the South Island of New Zealand. The chief scientist, Dr. Michael Gurnis, is the lead investigator on the South Island Subduction Initiation Experiment (SISIE). We collected OBS and MCS seismic data as well as some gravity, magnetics, and multibeam bathymetry. This is a collaboration with scientists and students from UT Austin and Victoria University of Wellington (New Zealand). Four Caltech students sailed on this cruise, and research is ongoing. Some results were presented by Gurnis et al. (2019) and Patel et al (2020).

Ongoing Geology Project

We have a collaboration with Seulgi Moon of UCLA and Arturo Martin of CICESE to study the process of continental microplate formation on Isla Angel de la Guarda, Gulf of California, Mexico. This involves field mapping of faults and faulted bedrock and terrace surfaces; OSL dating of the offset surfaces; and drone flights to collect air photos for use in constructing high resolution DEMs using structure-from-motion. Graduate student Leah Sabbeth from Caltech just finished her PhD on this project.

New Project with the Resnick Sustainability Initiative: Diffuse CO2 Emissions and Ecosystem Response at Costa Rican Volcanoes

This project is an interdisciplinary collaboration between Caltech and JPL for CO2/Lidar data collection and analysis examining spatial variations in diffuse emissions of carbon dioxide from volcanic areas in Costa Rica. The tropical CO2 fertilization effect is the single largest uncertainty in the terrestrial contribution to projections in climate. This pilot study will address how tropical ecosystems respond to increasing CO2, by surveying a modern ecosystem where local CO2 increases are measurable and can be related to vegetation response. We will also use the dataset for volcanic hazards studies to evaluate links between the observed pattern of CO2 variations and the tectonic structure and seismicity of the regions around the volcanoes. Initial data collection was delayed for one year due to the pandemic and is scheduled for the next dry season - February/March 2022.

WAVE student project, summer 2021

My WAVE student is analyzing thermal infrared hyperspectral data collected by The Aerospace Corporation over the Fish Creek Basin in southern California. The data were collected using the MAKO airborne sensor. The study area contains the active Elsinore fault as well as smaller faults, and a set of tilted and deformed sedimentary rocks recording the Pliocene evolution of the rift basin including marine sediments and the Colorado River Delta.

2020 undergraduate projects on Tectonics of Venus

Two students in the Caltech WAVE program worked under my supervision in summer 2020 on projects related to the tectonics of Venus. I hope to be involved in similar opportunities for students in the future!

____________________

Note to undergraduate students interested in applying for summer internships:
I cannot take any new interns in the months of May or June. If you send me an email asking about this, I will know you have not read my web site.

If you are an undergraduate (NOT in a combined master's program) and you are available to come for an internship during the time of the Caltech SURF program (mid June to mid August) then you have to apply through the SURF program, WAVE program, or similar Caltech program in January or early February each year..

Publications

For a complete publications list, see feeds.library.caltech.edu
2025-26
FS/Ge 16. First-year Seminar: Earthquakes. 6 units (2-0-4); first term, 2025-26. Earthquakes and volcanic eruptions constitute some of the world's major natural hazards. What is the science behind prediction and/or rapid response to these events? We will review the current understanding of the science, the efforts that have been made in earthquake and volcano forecasting, and real-time response to these events. We will learn about advances in earthquake preparation in Southern California, and volcanic eruption forecasting and hazard mitigation elsewhere. There is a required field trip to visit faults and volcanoes somewhere in southern California. First-year (undergraduates) only; limited enrollment.
Instructor: Stock
Ge 161. Plate Tectonics. 9 units (3-0-6); first term, 2025-26. Prerequisites: Ge 11 ab or equivalent. Geophysical and geological observations related to plate tectonic theory. Instantaneous and finite motion of rigid plates on a sphere; marine magnetic and paleomagnetic measurements; seismicity and tectonics of plate boundaries; reference frames and absolute plate motions. Interpretations of geologic data in the context of plate tectonics; plate tectonic evolution of the ocean basins.
Instructor: Stock
2024-25
Ge 122 abc. Field Geology Seminar. 6 units (1-3-2); first, second, third terms, 2024-25. Prerequisites: Ge 11 ab or Ge 101, or instructor's permission. Each term, a different field topic will be examined in both seminar and field format. Relevant readings will be discussed in a weekly class meeting. During the 3-day weekend field trip we will examine field localities relevant to the topic, to permit detailed discussion of the observations. Topic varies every year. Graded pass/fail. Ge 122b offered 2024-25 (second term only).
Instructor: Stock
FS/Ge 16. First-year Seminar: Earthquakes. 6 units (2-0-4); first term, 2024-25. Earthquakes and volcanic eruptions constitute some of the world's major natural hazards. What is the science behind prediction and/or rapid response to these events? We will review the current understanding of the science, the efforts that have been made in earthquake and volcano forecasting, and real-time response to these events. We will learn about advances in earthquake preparation in Southern California, and volcanic eruption forecasting and hazard mitigation elsewhere. There is a required field trip to visit faults and volcanoes somewhere in southern California. First-year (undergraduates) only; limited enrollment.
Instructor: Stock
Ge 161. Plate Tectonics. 9 units (3-0-6); first term, 2024-25. Prerequisites: Ge 11 ab or equivalent. Geophysical and geological observations related to plate tectonic theory. Instantaneous and finite motion of rigid plates on a sphere; marine magnetic and paleomagnetic measurements; seismicity and tectonics of plate boundaries; reference frames and absolute plate motions. Interpretations of geologic data in the context of plate tectonics; plate tectonic evolution of the ocean basins.
Instructor: Stock
2023-24
Ge 121 abc. Advanced Field Geology. 12 units (0-9-3); first, second, third terms, 2023-24. Prerequisites: Ge 120 or equivalent, or instructor's permission. For Ge 121a (Lamb): Ge 125 or instructor approval. Field mapping and supporting laboratory studies in topical problems related to the geology of the southwestern United States. Course provides a breadth of experience in igneous, metamorphic, or sedimentary rocks or geomorphology. Multiple terms of 121 may be taken more than once for credit if taught by different instructors.
Instructors: Lamb (a), Grotzinger (b), Stock (c)
Ge 122 abc. Field Geology Seminar. 6 units (1-3-2); first, second, third terms, 2023-24. Prerequisites: Ge 11 ab or Ge 101, or instructor's permission. Each term, a different field topic will be examined in both seminar and field format. Relevant readings will be discussed in a weekly class meeting. During the 3-day weekend field trip we will examine field localities relevant to the topic, to permit detailed discussion of the observations. Topic varies every year. Graded pass/fail. Topic: Anza-Borrego State Park. Ge 122b offered 2023-24 (second term only).
Instructor: Stock