Lithosphere-Asthenosphere boundary 100 km deep. Lithosphere-Asthenosphere boundary The Lithosphere-Asthenosphere boundary (LAB) represents a mechanical difference between layers in Earth’s inner structure. Earth’s inner structure can be described both chemically (crust, mantle, core) and mechanically. The Lithosphere-Asthenosphere boundary (referred to as the LAB by geophysicists) lies between Earth's cooler, rigid lithosphere and the warmer, ductile asthenosphere. The actual depth of the boundary is still a topic of debate and study, although it is known to vary according to the environment. The LAB is determined from the differences in the lithosphere and asthenosphere including, but not limited to, differences in grain size, chemical composition,
This Is What the Truth Feels Like few weeks before its release. The seventh track, "Send Me a Picture", has dancehall elements, and was described as a sexting ode by several publications; furthermore, Mapes stated the song has a "Bieber-hits-the-islands vibe", while Annie Zaleski of "The A.V. Club" summarized its meaning as "captur[ing] the delicious anticipation of a crush potentially texting a snap". "Red Flag" begins with "an intro that sounds like a melting violin", followed by Stefani scorning her ex: "This is what happens when you don't listen to what your mother say." Amanda Dykan of AltWire found it reminiscent of 2000's "Ex-Girlfriend" and compared Stefani's