In 2020, the COVID-19 pandemic put a hold on Liz Miller’s triathlon plans but not on her competitive nature. So, instead of swimming, cycling, and running her way to a medal, the Los Alamos National Laboratory geologist decided to “Everest”—to climb the elevation (29,032 feet) of Mount Everest—during a single bike ride.
On August 8, 2020, Miller, together with friend Lani Seaman of the Lab’s Surveillance Oversight group, completed the challenge virtually, which allowed them to undertake the effort using stationary bike trainers inside their own homes. Miller started at 4:30 a.m. and wrapped up just under 12 hours and 6,000 burnt-calories later. “You’ve got to be prepared for some very dark moments,” she says. “There were definitely some tears, and definitely some questions of ‘Why am I doing this?’”
Back at work
Meanwhile, in her job at the Laboratory, Miller never asks herself, “Why am I doing this?” As part of the Lab’s Earth Systems Observations group, she is involved in monitoring the globe for underground nuclear explosions.
“As you can imagine, a bad actor who wants to hide a nuclear test isn’t going to volunteer a lot of information regarding its size or whereabouts,” she says. However, by studying the seismic, acoustic, and chemical signatures generated by an explosion, scientists can learn more about it. As a geologist, Miller is most interested in understanding how rocks and subsurface features, such as faults, affect the signatures generated by an explosion, since the presence and magnitude of these signatures depends on the types of rocks they move through.
“Seismic monitoring stations are often positioned great distances from where a blast occurs. Gathering and integrating geologic information helps us figure out how far and how fast the signal traveled to determine where the blast originated,” Miller explains. “My job is to help build computer models of geographical areas of interest so that when seismic monitoring stations detect an event, we can use the seismic data and the geologic model to estimate an event location.”
Miller starts by asking what is known about the rocks in the area. Are they porous? How hard are they? How much water do they contain? What is the fracture network like? With that knowledge, she builds a framework model of the subsurface structure. “I like to equate my work to going grocery shopping,” Miller explains. “You start with an empty shopping cart and then, as you walk through the store, you pick different items off the shelf to fill it, which you then combine when you get home to make a recipe. Similarly, in building these computer models, I’m using a variety of ‘ingredients’ such as geologic maps and drilling data to best feed the computer model.”
Seismic waves will create very different signals depending on whether they’re moving through hard rock (such as granite) or softer rock (such as sandstone). “So when we create a model for a certain region of the world, we look at the topography of the location and use publicly available maps, GPS satellite data, and other open-source information to determine what type of rock lies underneath,” Miller explains. “We also look at clues such as nearby water sources, past earthquake data, and other seemingly minor details that can make a big difference in the accuracy of a model.”
Scientists then use these models to help pinpoint the location of the blast. The better the models are, the better the analyses of explosions can be, and the better informed leaders will be on what’s happening in remote locations around the world. All of this helps researchers monitor global nuclear weapon activities, thus giving them the information to make the world safer.
Hall of fame
Miller’s Everest ride was formally verified by the Hells 500 organization, which maintains an Everesting Hall of Fame. Miller is one of nearly 6,000 people who have completed the challenge. Will she ever try to do it again? No, she says, but then seems to reconsider. “You always forget the bad part,” she says. “You’re always like, ‘That was horrible.’ But then the next day you’re like, ‘Where do I sign up?’”