Hot dry rock geothermal energy makes use of hot fluids found naturally in basement rock; but such HWR conditions are rare. By far the bulk of the world’s geothermal resource base (over 98%) is in the form of basement rock that is hot but dry—with no naturally available water. This means that HDR technology is applicable almost everywhere on earth (hence the claim that HDR geothermal energy is ubiquitous). Typically, the temperature in those vast regions of the accessible crystalline basement rock increases with depth. This geothermal gradient, which is the principal HDR resource variable, ranges from less than 20 °C/km to over 60 °C/km,
Songs from the Underground Songs from the Underground Songs from the Underground is the second extended play released to the public by American rock band Linkin Park. It features songs previously released through the Linkin Park Underground fan club, as well as two previously unreleased live tracks from Projekt Revolution. "Songs from the Underground" features numerous songs released through Linkin Park Underground, the band's official fan club, as well as two live tracks from Projekt Revolution 2008. "And One" and "Part of Me" were included in the "Hybrid Theory (EP)" (the band's first extended play), "Dedicated" was a demo originally released on "LP Underground