A team of American scientists from the State University of New York at Buffalo has advanced the study of lava properties by developing and field testing an innovative device called a penetrometer. This tool is designed to assess the viscosity of molten rock, a crucial factor in understanding how lava flows during eruptions. The researchers reported their findings in the peer reviewed journal Review of Scientific Instruments (RSI).
To validate the instrument in real-world conditions, the team undertook a field expedition to an active volcanic site, Litli Hrutur in Iceland. Working at the source of lava provided essential data that laboratory simulations alone could not reproduce, enabling a closer look at how this material behaves under actual eruption conditions.
Determining lava viscosity is key to predicting flow rates and eruption dynamics. Yet obtaining reliable measurements is exceptionally challenging because igneous rock develops at scorching temperatures that can exceed 1000°C deep within a volcano. Traditional laboratory studies, while informative, often simplify the environment and cannot capture all the variables present during a true volcanic event.
In response, the investigators designed a device with a form reminiscent of a long lawn mower, optimized for use in harsh volcanic settings. Its rugged build allows it to be deployed on rough terrain and to survive the heat and ash that accompany active eruptions. The design emphasizes portability, durability, and straightforward operation, ensuring researchers can collect data even under demanding field conditions.
The core principle behind the lava penetrometer is straightforward: it measures the force required to push the tool into the lava and the time taken to reach a prescribed depth. By combining these two measurements, scientists can infer the viscosity of the surrounding molten material. Viscosity, a measure of a liquid’s resistance to flow, provides insight into how easily lava will move through volcanic conduits and landscapes once an eruption begins.
Field measurements conducted in Iceland revealed a broad spectrum of lava viscosities, ranging from roughly 300 pascal seconds up to about 34,000 pascal seconds as temperatures spanned from 1148°C to 1165°C. This wide variation underscores how temperature, composition, and crystallization influence lava behavior and highlights the importance of in situ observations for accurate modeling of volcanic activity.
The authors of the project emphasize that the penetrometer will enable the capture of new, location specific data on volcanic activity across diverse regions. Such data can improve risk assessment, hazard forecasting, and our general understanding of how magmatic systems evolve over time. The ability to compare viscosity measurements from different volcanoes helps scientists build more robust models of eruption dynamics and lava emplacement.
As a note on broader progress, earlier researchers explored the use of artificial intelligence to enhance eruption forecasting. These efforts aim to integrate diverse datasets, from seismic signals to gas emissions, to predict imminent activity and inform mitigation strategies. The integration of AI with physical measurement tools like the lava penetrometer represents a complementary approach, combining direct material properties with predictive analytics to better anticipate volcanic behavior.