Core–mantle boundary Core–mantle boundary The core–mantle boundary (CMB in the parlance of solid earth geophysicists) of the Earth lies between the planet's silicate mantle and its liquid iron-nickel outer core. This boundary is located at approximately 2891 km (1796 mi) depth beneath the Earth's surface. The boundary is observed via the discontinuity in seismic wave velocities at that depth due to the differences between the acoustic impedances of the solid mantle and the molten outer core. P-wave velocities are much slower in the outer core than in the deep mantle while S-waves do not exist at all in the liquid portion of
We Do What We Want decision to write a heavier and more hardcore album than they had done in the past. Commenting on the band's evolved sound, bassist/vocalist Toby Morrell said, "I don't think we ever thought we'd get as heavy as we are now, but I'm glad we have." Though Shelton was not an active member of Emery during the writing process for "We Do What We Want", he wrote the final track on the standard edition titled "Fix Me," and the song "Crumbling" from the deluxe edition. Regarding the album's lyrical themes, vocalist Toby Morrell stated: In the month of March 2011, an