The Journal of Volcanology and Geothermal Research recently published a study regarding the relationship between spectral emissivity and the temperatures of three different crystal-bearing basalts. It’s common for scientists to use thermocouples to measure high temperatures in such cases due to their sensitivity over a wide range. 

A thermocouple is a sensor that measures temperatures, consisting of two dissimilar metal wires connected at one end and joined to the thermocouple thermometer at the other end. Let’s look at a few key concepts of this exciting research.

Defining Spectral Emissivity

A substance’s ability to emit energy in the form of thermal radiation, such as lava flow, is referred to as its spectral emissivity. Lava flow can’t keep covering ground forever; eventually, it will cool down and precipitate. This causes its radiation features to evolve continuously because magma’s crystal concentration and composition alter significantly due to temperature changes. Understanding lava’s spectral emissivity is essential for volcanologists to obtain more accurate temperature estimates when using remote sensing data. 

The Temperature of Lava Flow

You can't trust volcanoes. One significant risk associated with active basaltic volcanoes is the eruption and flow of lava. Lava flows require environmental governance so that scientists and environmentalists can gauge the extent of damage they are capable of inflicting on surrounding areas. By consistently observing the lava flow and developing a detailed ground evolutionary model, volcanologists can determine the lava flow’s potential run-out distance. The accurate measurement of one variable is critical: the lava flow’s temperature. This is because it directly relates to the rheological properties of the progressing lava flow. 

Measuring the Lava Flow’s Temperature

There are two ways of measuring lava temperatures: directly and remotely. We’ll touch upon the mechanism of both techniques.

  1. Direct Measurement

With this method, a thermocouple’s probe is slid into the magma with the temperature observed on a hand-held instrument. If a specific flow isn’t particularly active, it’s easier for an individual to close in on it and wait until the thermocouple has equilibrated in the lava. However, this is rarely the situation environmental scientists encounter, making it hard to obtain precise temperature readings. As the lava flow’s temperature increases, the volcanologist measuring this variable becomes increasingly less comfortable in their surroundings and retreats. 

  1. Remote Measurement

Remote sensing techniques use air, ground, and satellite-based technologies to monitor lava flows. They are more common than direct measurements, given the lack of advanced geographical navigation and penetration technology and the uncertain nature of volcanoes. These remote processes analyze the lava body's mission flux (radiance) at specific wavelength ranges, enabling scientists to use Planck’s law and find the temperature.

There’s no doubt that measuring the spectral emissivity of completely molten volcanic rocks is complicated and taxing. However, carrying out this intricate and dangerous research is essential for opening up new realms in studying volcanoes and geothermal energy. If you’re interested in the results collected from this particular study, you can access them on ScienceDirect.

If you’re a professional looking to research spectral emissivity and the temperature of a different volcanic material, you’re probably aware that you need to use thermocouples. Luckily, they’re easily accessible. For example, thermocouples by Pyrosales can be purchased online and delivered to your doorstep. Pyrosales offers thermocouple devices that can be used in various industries, so take your time and select one that can meet your needs.