Beneath the Surface
Unraveling Earth’s Hidden Plumbing with Volcanologist Meredith Townsend
While many associate volcanology with the dramatic spectacle of erupting lava and rugged fieldwork, geoscientist Meredith Townsend is approaching volcanoes from another perspective—one that is focused, methodical, and deeply analytical. Specializing in the internal processes that govern volcanic activity, Townsend’s research centers not on eruptions as they happen, but on the underlying systems that drive them — the movement of magma beneath the surface and the ways in which these dynamics interact with broader planetary forces.
Part of Townsend’s research begins far from the drama of live eruptions. Instead, she often works in regions where volcanoes have long gone quiet—extinct giants whose subterranean "plumbing systems" are now visible thanks to erosion. Townsend, an assistant professor of Earth and environmental sciences, studies regions where mountains have been worn down over millennia, revealing the hardened pathways once carved by ascending magma.
Central to her research are geological structures known as dikes—fractures in the Earth's crust filled with once-molten rock. Her work investigates the forces that control the direction of dike propagation and whether dikes ultimately reach the surface or stall underground. These questions are critical not only for understanding how volcanoes form but also for improving the accuracy of eruption forecasting.
Combining geological mapping with petrographic analysis, Townsend’s team examines the alignment of crystals within ancient magma flows—microscopic, time-stamped records of how and where the molten rock once moved. This approach enables Townsend’s team to reconstruct the pathways of magmatic ascent and, importantly, to identify the factors that determine whether a magma flow breaches the surface.
Many seismic events that signal potential eruptions ultimately result in "failed eruptions," where magma remains trapped beneath the surface. A better understanding of magma transport processes could help reduce false alarms and more reliably identify genuine eruption threats.
“One of the big questions at any potentially active volcano is where will the next eruptive vent form? This is an especially important question for the large stratovolcanoes we have in the western U.S., such as Mount St. Helens and Mount Rainier. We tend to think of eruptions as coming out the top of the volcano, but oftentimes volcanoes erupt at lower elevations, sometimes near the base or even not at the main center of the volcano at all. And a lot more people live at these lower elevations, so it's definitely of interest to figure out why magma would go to the top versus out the sides. I'm trying to understand what controls whether a dike is going to make it to the top or come out the side or just stall underground completely and be a failed eruption.”
From Ancient Rocks to Climate Feedback
Although Townsend began her career studying long-extinct volcanoes, her current research spans both deep geological time and urgent contemporary issues. In an ongoing project in southern Chile, she and a multidisciplinary team are investigating a potential feedback loop between volcanic activity and climate change.
It is well established that volcanoes can influence climate by emitting gases such as carbon dioxide and sulfur dioxide, which can drive global warming or cooling. But Townsend is exploring the reverse relationship: Can climate change influence volcanic activity?
To address this question, Townsend and her collaborators are analyzing the geologic record of eruptions from six volcanoes. Specifically, they are studying how glaciers and ice sheets affect volcanic behavior—an increasingly important inquiry as global ice loss accelerates due to climate change. When thick ice sheets expand and contract, they apply and then release pressure on the Earth's crust. Townsend's team aims to determine whether the removal of ice (decompression) leads to increased volcanic eruptions and whether the cycles of ice growth and sudden melting alter how magma accumulates and moves beneath the surface.
“There are over a hundred volcanoes under the West Antarctic ice sheet. What happens when the ice is gone?”
To explore these questions, Townsend and her collaborators are looking at the Southern Volcanic Zone of the Andes, where glaciers from the Patagonian Ice Sheet once covered many volcanoes with up to 2 kilometers of ice during the last ice age (about 35,000 to 18,000 years ago). Afterward, the glaciers melted quickly between 18,000 and 15,000 years ago.
The team’s work involves both field sampling and sophisticated modeling. While geologists collect and date volcanic rocks to track eruption frequency, climate scientists on the project reconstruct the history of glaciation by locating and dating glacial deposits. Townsend’s contribution lies in building dynamic computer models that simulate how changes in surface pressure from glacial melting might accelerate or delay eruptions.
In an era of accelerating climate change, this question is more than academic. “There are over a hundred volcanoes under the West Antarctic ice sheet,” she points out. “What happens when the ice is gone?”
Townsend’s research is increasingly driven by large-scale questions that demand cross-disciplinary collaboration. The deeper she delves into the mechanics of magma movement, the more she finds herself at the intersection of tectonics, climate, and planetary evolution. Rather than narrowing her scope, her research is expanding into more integrated models of Earth systems. From how magma generation relates to tectonic plate motion, to the crustal evolution that underpins continental growth, Townsend’s work is steadily contributing to a broader understanding of Earth as a dynamic, interconnected whole.
Building Toward Bigger Questions
At its heart, Townsend’s work remains focused on one deceptively simple question: what allows some magma to erupt, while the rest cools unseen beneath our feet? The implications of this question reach far beyond geology, touching everything from hazard mitigation to the story of Earth’s evolving atmosphere.
“Earth science is such a broad field that it’s inherently interdisciplinary,” Townsend says. “To study something like volcanoes, we pull data from every direction—from the chemistry of erupted rocks to geophysical imaging and real-time monitoring. I need to speak the language of both geochemists and geophysicists. My goal is to build models that bring all these different kinds of data together.”
But the deeper Townsend digs into the role of ice forcing, the more she sees how volcanoes are woven into the Earth’s larger systems. “They affect climate—and climate affects them. Magmatism influences plate tectonics, which in turn drives volcanism. These connections are really fascinating. And we still don’t understand some fundamental things about our planet, like why some magma erupts while some freezes underground. That has huge implications for how the Earth’s crust and climate evolve over time. All of this work ties into the big picture, which is why it's so exciting to be working on more integrated projects.”