The word "caldera" evokes images of serene lakes nestled in volcanic craters. But behind the picturesque scenery lies a complex reality—one that's increasingly relevant as we chase clean energy solutions. Recent reports highlight the dual nature of calderas, specifically focusing on lithium extraction and seismic activity. What do these opposing forces mean for the future?
The McDermitt Caldera, straddling Nevada and Oregon, is now seen as a potential lithium El Dorado. A peer-reviewed study indicates unusually high concentrations of lithium in its clays, particularly at Thacker Pass. The lithium-dense layer boasts grades high enough for industrial-scale extraction, sitting conveniently close to the surface. This is a big deal considering the U.S. still imports most of its lithium (used in batteries). A domestic source could dramatically shorten supply chains and stabilize prices. Ancient volcanic crater could turn the U.S. into the new global epicenter of clean energy
But here's where the narrative gets complicated. While McDermitt Caldera promises energy independence, another study focuses on the Campi Flegrei caldera in Italy, linking seismic activity to magmatic activity and hydrothermal fluid circulation. (Basically, underground rumblings.) The study investigates earthquake source properties, noting how rupture velocity (the speed at which earthquake ruptures propagate) is tied to stress distribution and energy partitioning. In Campi Flegrei, they've observed over 10,000 earthquakes in the past decade, most concentrated between 1 and 4 km depth.
The connection? Both calderas are active geological zones. Extracting lithium requires disturbing the earth, potentially impacting the delicate balance within these volcanic structures.
Thought leap: It's crucial to question if the environmental review for Thacker Pass (approved in 2021) adequately accounted for the potential seismic impact of large-scale lithium extraction. What models were used? What baseline seismic data was available? It's naive to assume that digging massive holes in the ground won't have any effect.
The lithium study claims Thacker Pass has lithium concentrations reaching about 1% by weight. That’s roughly twice as rich as most other clay-based lithium deposits. But how consistent is this concentration across the entire deposit? Averages can be misleading; we need to see the standard deviation to understand the variability.
Meanwhile, the Campi Flegrei study uses a "LPDT-method" (logarithm of the P-wave displacement amplitude vs time) to estimate rupture velocity and stress drop. It’s worth noting that this method, while validated in other applications, relies on parametric modeling. (That is, certain assumptions.) The study acknowledges the uncertainty associated with rupture velocity estimation, particularly for small earthquakes. Earthquake rupture velocity and stress drop interaction in the Campi Flegrei volcanic caldera
Personal aside: And this is the part of the report that I find genuinely puzzling. Why the conflicting narratives about calderas? One is presented as a clean energy solution, the other as a potential seismic hazard. Are we not connecting the dots here?
The Campi Flegrei study notes that larger-magnitude earthquakes—including the Md 4.6 of March 13, 2025—followed similar rupture trends. However, that Md 4.6 event was "a compound sequence consisting of two closely timed shocks (Mw 3.3 and Mw 4.0)." This isn’t a single large rupture, but two smaller ones in quick succession. It's a crucial distinction that affects how we interpret the overall seismic risk.
The spatial and temporal distribution of seismicity supports a model where earthquakes are primarily driven by changes in loading conditions on pre-existing faults around the caldera. If this is true, then any activity that alters loading conditions (like, say, large-scale mining) could exacerbate the problem.
We're essentially weighing the promise of clean energy against the potential for increased seismic risk. Both studies highlight the importance of understanding the complex geological processes at play within calderas. We need more data, more rigorous modeling, and a more holistic assessment of the potential consequences before we commit to large-scale lithium extraction in these sensitive environments. Otherwise, we risk solving one problem while creating another.
