
Terry Miller is a Subsurface Modeling Research Technologist for the Computational Earth Science group at Los Alamos National Laboratory. She commands — and develops — special tools that allow her to peel back and render the hidden layers of geology for subsurface simulations. Her work benefits research into environmental health, cleaner energy and national security. Photo Courtesy LANL
LANL NEWS – SPECIAL EARTH DAY FEATURE
Terry Miller lives near a park that boasts a waterfall, a jaw-dropping gorge and the remains of ancient lava flows. Down steep switchbacks to the Rio Grande and through grassy fields with mountain views, she trains search-and-rescue dogs.
She’s often drilling dogs or responding to wilderness rescues when she’s not shaking up earth science at Los Alamos National Laboratory.
Miller is a Subsurface Modeling Research Technologist for the Computational Earth Science group. She commands — and develops — special tools that allow her to peel back and render the hidden layers of geology for subsurface simulations. Her work benefits research into environmental health, cleaner energy and national security.
At her favorite park, she could watch the Rio Grande meandering through White Rock Canyon and imagine how this popular scenic overlook might break down into area and volume. Hypothetically speaking, with her laptop and some choice slices of data, she could capture volcanic scenes such as this in mind-blowing geologic renderings.
Miller can create a 2-dimensional mesh that looks like a net. Or a 3-dimensional mesh that looks like Legos. These meshes capture vital information about physical processes.
“Nearly all the projects in our group count on her support in one way or another,” says Carl Gable, her supervisor and mentor in mesh-generation. “Miller deserves the Oscar for best supporting actor on a science team. Her responsibilities and capabilities have continued to smoothly evolve to meet the changing needs of the staff she supports.”
An expert in mesh generation and model setup for geologic applications, Miller is literally on the edge of new advancements in this field, pushing boundaries in ways that help scientists to do their best work, to dig deeper.
“Mesh generation subdivides geometric spaces into shapes or cells whose areas and volumes are used in the physics represented,” Miller says. “These cells and volumes are arranged based on the criteria required by the physics and the modeling software.”
Miller’s computer-generated renderings help scientists model multi-material complex geometries to understand and solve subsurface flow and transport problems, that is, how water and other liquids move beneath the earth’s surface.
“Geologic modeling of subsurface flow and transport are simulations of complex underground systems we want to explore, Miller explains. “For instance, if we want to understand contamination moving through rocks in relation to a deep aquifer, we cannot try to represent each rock and its type deep under the earth. Through drill hole examinations and geologist expertise, we can simplify rock types into layers. We then define areas to represent the aquifer and a contamination source. The physics we run can then simulate the behavior of contamination as it moves relative to wet or dry rock.

Miller can create a 2-dimensional mesh that looks like a net. Or a 3-dimensional mesh that looks like Legos. These meshes capture vital information about physical processes .Photo Courtesy LANL
The beauty of unstructured meshes:
In 2020, Miller received an R&D 100 Award as part of a team that developed Amanzi-ATS, open-source software that models complex environmental systems across multiple scales. This innovation includes the most complete suite of surface/subsurface processes, built on a flexible infrastructure.
Amanzi–ATS has been used to analyze pristine local watersheds, wildfire impact on watersheds, subsurface contaminant transport, the effect of a warming climate on the Arctic tundra and groundwater in fractured porous media.
David Moulton of Applied Mathematics and Plasma Physics, who leads the multi-lab Amanzi-ATS development team across several projects, explains why Miller’s meshes are so vital. “To simulate flow of water on the surface and underground, we need to accurately represent both the topography and underground features such as clay layers and faults. But nature doesn’t fit nicely in a box, and these features don’t follow straight lines on a grid. Instead, we need to leverage the flexibility of unstructured grids to represent these features in our Amanzi-ATS simulations.”
A 2017 R&D 100 Award to Discrete Fracture Network Modeling Suite, which transforms simulations of flow and transport through fractured rock, uses LaGriT to generate 3-dimensional discrete networks for modeling flow and transport through fractured media.

Terry Miller works outside. Photo Courtesy LANL
The secret foundation of close-knit teams:
Influenced by her interests, Miller finds fresh ways to peer inside the strata below the Earth’s surface, while inspiring teams to excel.
“I like that the area of mesh generation is still growing. There is more to learn and more to figure out,” she says.
Last year, in a presentation Miller made about an R&D project’s “hard challenges” such as complex geometry and a complicated workflow, she added a slide picturing “hard challenges” carried out by New Mexico Search and Rescue responders.
“Sharing your passion with others is a good foundation for team building,” she says. “I know my love for the dogs and search work inspires others, and hope my excitement for new meshing technologies enhance the work experience for those I work with.”
Miller draws inspiration from everywhere.
“Something that has impressed me working on searches is the value of every team member,” she explains. “The success of the search depends less on the individual, but rather on the efforts of all responders and how well they are deployed relative to their skills. It is this aspect of search teams that gave me the idea of a Software Committee made up of experts in different tools working across all the major projects. These advisors have helped shape Software QA policy and provide help and tools to improve efficiency and quality of our work.”
Career moves:
Beneath the surface of Miller’s career are some unexpected layers. In high school, she took up photography as a hobby and aspired to be a physicist.
But then, as a college freshman, she backed down. “The department counselors talked me out of that choice as they felt I would not be able to find employment as a woman. The field was dominated by men at the time,” Miller says. “I quit school to start a business with a friend doing private detective and process-serving work.”
Eventually Miller found her way back to photography, working for a company with photo processing labs. She rose to VP of marketing, with an office in downtown Denver, but didn’t enjoy it. “It was more about luncheons and smiling for corporate executives and not much to do about photography,” she says.
This is when Miller, in her early 40s, began looking for a career change. “I wanted to work in the sciences and learned that CU Boulder offered degrees in Computer Applications in Math. I had already satisfied most the electives and all the math requirements. This was the late 1990s, the age of the internet and the development of object-oriented languages like Pascal.”
While earning her degree, Miller had a position with the National Geophysical Data Center (NGDC), which led to a graduate research assistant position at Los Alamos with the Earth and Environmental Science group.
“As I drove to Los Alamos to start my job, I was stunned by the beauty and open skies of this land. And what a treat to live within minutes of uncrowded outdoor hiking in diverse lands from high desert to our mountain forests,” Miller says. “I was lucky to end up in a challenging and interesting position with people I enjoy and admire and to live in a place so suited to my enjoyment of the outdoors.
In 2020, Terry Miller received an R&D 100 Award as part of a team at Los Alamos National Laboratory that developed Amanzi-ATS, open-source software that models complex environmental systems across multiple scales. Since then, the software has been used to analyze pristine local watersheds, wildfire impact in New Mexico, and the effect of a warming climate on the Arctic tundra and groundwater in fractured porous media, among other things.
Miller’s computer-generated renderings help scientists model multi-material complex geometries to understand and solve subsurface flow and transport problems, that is, how water and other liquids move beneath the earth’s surface. Photo Courtesy LANL
The Discrete Fracture Network Modeling Suite, also an R&D 100 award winner, transforms simulations of flow and transport through fractured rock and uses LaGriT to generate 3-dimensional discrete networks for modeling flow and transport through fractured media. Image Courtesy LANL