Wave velocity variation with temperature: influential properties of temperature coefficient ($$\partial {\varvec{V}}/\partial {\varvec{T}}$$) of selected rocks

The intrinsic compressional and shear wave’s velocities of rocks decrease with increasing temperature. An important parameter that quantifies the temperature effect on rocks’ wave velocities is the temperature coefficient ( $$\partial V/\partial T$$ ), which is the gradient of the linear relationship between the wave velocity and temperature. This study investigated properties affecting the temperature coefficient of selected lithology in Ogun State Southwestern Nigeria. The samples were heated and the compressional velocities were measured at a constant pressure of 0.01 GPa and 50 °C intervals from 50 to 300 °C. The result showed that both elastic modulus and density varied directly with the absolute compressional temperature coefficient, $$\partial {V}_{P}/\partial T$$ while porosity had an inverse variation. The elastic modulus, density, and porosity exhibited a notable effect on the temperature coefficient with their respective correlation coefficient as 0.98495, 0.97594 and − 0.93787. Clay content, which also exhibited an inverse variation with the temperature coefficient had a correlation coefficient of − 0.44668. For both the same and different rock types, elastic modulus is the most important property that controls the temperature coefficient.