
Alex Rinehart, PhD
Assistant Professor
Earth and Environmental Science
- alex.rinehart@nmt.edu
- 575 - 518 - 8278
- MSEC 244
I study how water and soil and rocks interact, with focuses on using surface deformation
and changes in gravity can be used to understand subsurface water movement, the mechanisms
of water and chemical weakening on rock strength and progressive rock failure, and
on various applied hydrogeologic and vadose zone projects. I have worked as an assistant
professor here at NMT since 2019.
Career path:
I completed a BS in Mathematics (UNM), followed by a MS in Hydrology (NMT) and a PhD
in Earth Sciences (emphasis in Geophysics, NMT). My PhD work was completed as a graduate
intern in the Geomechanics Department at Sandia National Labs, an incredible experience
of working on basic science in outstanding service to the country and world. I then
served as a hydrogeologist at the New Mexico Bureau of Geology for five years. At
the Bureau, I worked on hydrogeologic studies for small communities, state-wide assessments
of groundwater storage change and natural hazards, and supporting experimental work
understanding carbon capture and underground storage.
To be able to mentor young people, I became an assistant professor in 2019. I have
spent my life in New Mexico, but intellecutally have moved across disciplines within
the earth sciences.
Research:
My research crosses hydrology, geophysics and rock mechanics to understand applied
hydrologic questions, hydrogeodesy, reservoir and geothermal coupled processes, and
the role of water and fracture in landscape development.
Applied hydrology
Currently, my group is working on understanding basin-scale sources of groundwater
using environmental tracers and water chemistry (student: Ethan Williams), and on
measuring hydrologic properties of soils to understand how climate change will alter
the water balance (student: Kyle Gallant).
This work is field and lab intensive. The groundwater studies involve measurement
of groundwater levels, surface water flow, collection of water quality samples and
analysis of the water quality samples. By doing integrated surveys, we can understand
the different ways groundwater and surface water are connected.
Research in the vadose zone largely consists of opening and describing soil pits,
followed by laboratory analysis of physical, chemical and hydrologic properties. This
work is supporting ecosystem climate manipulation experiments at the Sevilleta Long-Term
Ecological Research station.
Hydrogeodesy
Normal hydrologic approaches either use direct measurements of groundwater levels
to understand aquifers usually at single points, or use water quality methods such
as stable water isotopes, groundwater age dating, or general chemistry to indirectly
understand how the larger system works.
Hydrogeodetic techniques, which link surface deformation measured by GPS or satellite,
or small changes in gravitational acceleration to changes in water storage in aquifers,
hold the promise to revolutionize how we understand water movement in the subsurface.
Because they average over large areas, single sets of measurement can tell you how
an entire portion of an aquifer or watershed behaves--even up to entire mountain ranges.
Currently, I am performing repeat gravity surveys on land to understand focused recharge
supporting Dan Cadol, and working with researchers at UA-Fairbanks on using satellite-based
deformation mesurements (InSAR) to understand groundwater changes across all of New
Mexico. I am also supporting work at NMT using tiltmeters to understand flow in karst
conduits in Florida.
This work combines data analysis, modeling, and field deployments; something for everyone.
The repeat gravity work requires someone who can do extremely careful, detailed field
work. The measurements are on the edge of the current instrumentational limits.
Environmental progressive rock failure
Recent research has shown that the water-mediated fracturing at the surface controls
the rate of mechanical weathering and water movement in bedrock regions. The previous
paradigm was that fracture occured at a critical (high) stress. Now, we believe that
fracturing happens during thermal fatigue and chemically controlled stress corrosion
fracture. This means that 'standard' rock properties may not predict the mechanical
weathering of rocks and landforms. Rather, subcritical fracture properties--mostly
mediated by salts and water--will.
This work is done in collaboration with geomorphologists, geomechanicians, hydrologists
and engineers, linking land surface ages to rock properties via measurements and models.
My group is focused on performing laboratory testing of rocks under controlled environmental
conditions, providing key observations of process and properties to inform geomorphic
interpretations.
We are currently performing tests in collaboration with UNC-Charlotte and Colombia
University focused on mechanical weathering in hyper-arid, frozen environments.
Thermo-hydraulic-mechanical-chemical processes in subsurface energy
We are answering questions of how to predict how fluids like water, CO2 and hydrogen
interact with each other and rocks. These questions are vital for current effort of
climate change mitigation. Pursued experimentally, we run extended experiments simulating
reservoir conditions with as we push different fluids through rocks and monitor changes
in chemistry, strength and permeability. This information is then used by modelers
and engineers to understand if a system is appropriate as a storage reservoir or as
a geothermal resource.
This work is laboratory intensive, with the student performing high-pressure and high
temperature experiments measuring hydraulic and mechanical properties, performing
chemical analysis, and using petrographic (thin section) observations to understand
what happened to the samples.
Current projects include supporting DOE CarbonSafe projects, the DOE Southwest Carbon
Sequestration Partnership, and DOE-funded research on rare-earth elements in coal.
We are actively seeking projects in CCUS, hydrogen storage and geothermal.
Teaching:
- GEOL 440: Hydrological Theory and Field Methods
- HYDR 514: Vadose Zone Hydrology
- HYDR 555: Rock Fracture in Geologic Settings
- HYDR 556: Natural Complexity
- HYDR 558: Environmental Tracers in Hydrology
- GEOL 482 / HYDR 572: Special Topics: Engineering Geology
- GEOP 505 / MATH 587: Time Series Analysis
Current Group Members:
Andrew Luhmann (Wheaton College, assistant professor)
Ronni Grapenthin (University of Alaska - Fairbanks, assistant professor )
Sai Wang (research associate, PRRC)
Robert Czarnota (research associate, PRRC)
Jason Simmons (research associate, PRRC)
Ethan Williams (MS, Hydrology, E&ES, NMT)
Marissa Fichera (PhD, Hydrology, E&ES, NMT, beginning Spring 2023)
Kyle Gallant (BS, Geology, E&ES, NMT)
Antonio Chavez (BS, Environmental Science, E&ES, NMT)
Emily Graves (PhD, Geophysics, UAF)
Graduated Group Members:
Samuel Otu (MS, Hydrology, E&ES/PRRC, NMT)
Jason Simmons (MS, Hydrology, E&ES/PRRC, NMT, now a research associate at PRRC)
Zhidi Wu (MS, Hydrology, E&ES/PRRC, NMT, Luhmann was advisor)