How do the lithosphere and asthenosphere differ?
Asthenosphere is more yielding to perristent stress and softer than the lithosphere. It is a low-viscosity shell
Asthenosphere is in-between lithosphere and a part of the upper mantle.
It extends. from about 100 km, to nearly 700 km.
The broad classification for the Earth's interior, based on mechanical properties, is lithosphere, asthenosphere,mesosphere, outer core and the spherical inner core.
As the natural seismic-wave propagation provides data for analysis, the furthering of research is ever dependent on seismographs made during/before/after the occurrence of earthquakes.