Schematic figure showing the relationship between seismicity and temperature. In the shallower region, the temperature is low and ordinary earthquakes occur (stick–slip behavior). At depths where temperature reaches 350°C (orange line), some minerals start to deform in a ductile manner, and seismic coupling weakens. Below the depth where temperature exceeds 600°C (red line), the entire rock deforms in a ductile manner (stable slip), and neither earthquakes nor tectonic tremors occur. Tectonic tremors occur at locations where temperatures are around 600°C, just before stable slip takes over with depth.