When talking about the Earth, we discuss about the outer parts, the surface, and the inner parts. In this article, the talking is the definition of Asthenosphere.
Asthenosphere is defined as a region of the earth’s upper mantle at a depth of approximately 75 to 100 kilometers, characterized by low mechanical strength, attenuation of seismic shear waves, and partial melting. The term was firstly coined in the 1910 by Joseph Barrell, a geologist, to describe the zone in which isostatic adjustment occurs and basaltic magmas are generated. With the development of plate tectonics in the 1960s, the asthenosphere is now understood as the plastic zone over which the rigid plates move.
With the confirmation of the earth’s core, it became clear that the earth had a three-layer structure which are crust, mantle and core. But, in the depth of the mantle was not known. In the 1950s, Anglophone scientists realized it had already been identified by Croatian seismologist Andrija Mohorovicic, who in 1909 discovered the discontinuity in seismic waves under the continents at a depth of about 45 kilometers that now bears his name. However, the core-mantle distinction was confounded by Gutenberg’s discovery of the attenuation of S-waves in a region below the crust; at a depth of about 80 kilometers. Gutenberg suggested this was a of partial melting, which he called the asthenosphere. He was borrowing the term coined by geologist Joseph Barrell to describe the weak zone in which isostatic compensation occurred. It was not until the 1960s that this idea was generally accepted, when the distinction between the lithosphere and asthenosphere became a foundation of plate tectonics.
Reference: Encyclopedia of Physical Science and Technology – Earth Sciences, 2001, Naomi Oreskes.
Asthenosphere is defined as a region of the earth’s upper mantle at a depth of approximately 75 to 100 kilometers, characterized by low mechanical strength, attenuation of seismic shear waves, and partial melting. The term was firstly coined in the 1910 by Joseph Barrell, a geologist, to describe the zone in which isostatic adjustment occurs and basaltic magmas are generated. With the development of plate tectonics in the 1960s, the asthenosphere is now understood as the plastic zone over which the rigid plates move.
With the confirmation of the earth’s core, it became clear that the earth had a three-layer structure which are crust, mantle and core. But, in the depth of the mantle was not known. In the 1950s, Anglophone scientists realized it had already been identified by Croatian seismologist Andrija Mohorovicic, who in 1909 discovered the discontinuity in seismic waves under the continents at a depth of about 45 kilometers that now bears his name. However, the core-mantle distinction was confounded by Gutenberg’s discovery of the attenuation of S-waves in a region below the crust; at a depth of about 80 kilometers. Gutenberg suggested this was a of partial melting, which he called the asthenosphere. He was borrowing the term coined by geologist Joseph Barrell to describe the weak zone in which isostatic compensation occurred. It was not until the 1960s that this idea was generally accepted, when the distinction between the lithosphere and asthenosphere became a foundation of plate tectonics.
Reference: Encyclopedia of Physical Science and Technology – Earth Sciences, 2001, Naomi Oreskes.