Question

Where is the top of the asthenosphere is closest to earth's surface ________?

Answer 1

The top of the asthenosphere is closest to Earth's surface at subduction zones, where one tectonic plate is forced beneath another. This process leads to partial melting of the asthenosphere and the formation of volcanoes, which are often closer to coastlines where subduction occurs, as exemplified by the Andes on the western coast of South America.

Step-by-step explanation:

The asthenosphere is closest to Earth's surface at tectonic plate boundaries, specifically at areas where plates are being forced together, such as subduction zones. These are typically located off the coastlines of continents, where an oceanic plate is forced beneath a continental plate or another oceanic plate. As the subducting slab descends, it encounters increasing temperatures and pressures, leading to partial melting of the asthenosphere above it.

Volcanoes are generally closer to the coastline at subduction zones because the process of subduction provides a mechanism for partial melting of the mantle material, which then rises through the overlying crust to form volcanoes. An example of this is the western coast of South America, where the Nazca Plate subducts beneath the South American Plate, creating the Andean volcanoes close to the coast.

Answer 2

The top of the asthenosphere is closest to the earth's surface underneath OCEANIC CRUST. The asthenosphere is the area of the mantle beneath the lithosphere that is solid, but hotter than the rock above it. This layer can low under pressure and function as a soft , weak zone over which the lithosphere may move.

of the two types of crust, continental and oceanic; the latter is the thinnest. oceanic crust can be as little as 5km thick while continental crust can be up to 90km thick at the mountain ranges.