Thermophysical properties of a volcanic rock material
Hans-Peter Ebert, Frank Hemberger, Jochen Fricke, Ralf Büttner, Steffen Bez, Bernd Zimanowski
To simulate and predict the behaviour of a lava flow, it is essential to have a thorough knowledge of its thermophysical properties. Therefore, thermal conductivity, specific heat, and viscosity of volcanic rock material were determined in a wide temperature range. Especially, the properties of the molten material were investigated in detail. The material was taken from the Pietre-Cotte lava flow located on the isle of Vulcano, north of Sicily. The thermal conductivity of the material was determined in the temperature range 293 – 1623 K by the hot-wire method. Melting occurs above 1100 K. The specific heat was measured by differential scanning calorimetry between 347 and 1671 K. The viscosity of the lava melt was determined with a rotational viscometer HAAKE M5. The viscometer was enclosed in a high-temperature furnace optimised for the temperature range 1373 – 1598 K.