The lithosphere-asthenosphere boundary divides the rigid lid from the weaker mantle and is fundamental in plate tectonics. However, its depth and defining mechanism are not well known. We analyzed 15 years of global seismic data using P-to-S (Ps) converted phases and imaged an interface that correlates with tectonic environment, varying from 95 +/- 4 kilometers beneath Precambrian shields and p...

Oceanic lithosphere provides an ideal location to decipher the nature of the lithosphere-asthenosphere system which is vital to our understanding of plate tectonics. It is well established that oceanic lithosphere cools, thickens, and subsides as it ages according to the conductive cooling models. Yet this simple realization fails to explain various observations. For example, old oceanic lithos...

The mobility of the lithosphere over a weaker asthenosphere constitutes the essential element of plate tectonics, and thus the understanding of the processes at the lithosphere-asthenosphere boundary (LAB) is fundamental to understand how our planet works. It is especially so for oceanic plates because their relatively simple creation and evolution should enable easy elucidation of the LAB. Dat...

The lithosphere–asthenosphere boundary and the tectonic and magmatic history of the northwestern United States a r t i c l e i n f o a b s t r a c t Keywords: scattered waves lithosphere lithosphere–asthenosphere boundary mid-lithospheric discontinuity This study explores the properties of the lithosphere–asthenosphere boundary (LAB) and other shallow mantle discontinuities across the diverse g...

a r t i c l e i n f o a b s t r a c t Keywords: lithosphere–asthenosphere boundary Northeastern margin of the Tibetan Plateau Receiver functions Whether or not the Asian lithosphere has underthrusted beneath the Tibetan Plateau is important for understanding the mechanisms of the plateau's growth. Using data from the permanent seismic stations in northeastern Tibetan Plateau, we studied seismic...

[1] S-to-P (Sp) scattered energy independently confirms the existence of a seismic velocity discontinuity at the lithosphere-asthenosphere boundary that was previously imaged using P-to-S (Ps) scattered energy in eastern North America. Exploration of the different sensitivities of Ps and Sp scattered energy suggests that the phases contain independent yet complementary high-resolution informati...

The boundary between the lithosphere and asthenosphere is associated with a platewide high-seismic velocity "lid" overlying lowered velocities, consistent with thermal models. Seismic body waves also intermittently detect a sharp velocity reduction at similar depths, the Gutenberg (G) discontinuity, which cannot be explained by temperature alone. We compared an anisotropic tomography model with...

S U M M A R Y An assumption of isothermal and static asthenosphere as the normal state of sublithospheric mantle, as commonly employed in studies of terrestrial magmatism, may be physically implausible for a system cooled from above. The growth of an unstable thermal boundary layer at the base of the lithosphere can lead to small-scale convection, so asthenosphere is expected to be usually conv...