Question

The boundary where crust gives way to mantle is called the _______. A. Asthenosphere b. Mesosphere c. Mohorovicic discontinuity d. Vernian divide please select the best answer from the choices provided a b c d.

Answer 1

The boundary where the crust gives way to the mantle is called the c. Mohorovicic discontinuity or Moho.

Step-by-step explanation:

The boundary where the crust gives way to the mantle is called the Mohorovicic discontinuity, also known as the Moho. It is named after Croatian seismologist Andrija Mohorovicic, who discovered the boundary in 1909. The Mohorovičić Discontinuity, or Moho, is a seismic boundary between the Earth's crust and mantle. Named after seismologist Andrija Mohorovičić, it marks a transition from the solid crust to the denser mantle, typically occurring at depths around 5 to 10 kilometers beneath ocean floors and 20 to 70 kilometers beneath continents.

Seismic waves change velocity at this boundary, revealing variations in Earth's composition and providing valuable insights into the planet's internal structure and dynamics. The Moho is a seismic boundary that marks the change in composition and density between the crust and the upper mantle.

Answer 2

The boundary between Earth's crust and mantle is the Mohorovicic discontinuity, the correct answer being c. Mohorovicic discontinuity. It signifies the transition from the crust's seismic wave velocities to those in the mantle.

Step-by-step explanation:

The boundary where the crust transitions to the mantle is known as the Mohorovicic discontinuity. This discontinuity is recognized by a change in seismic wave velocities as they travel from the crust into the mantle. Considering the choices provided, the best answer is c. Mohorovicic discontinuity.

The lithosphere and the asthenosphere are different divisions based on mechanical properties. The lithosphere includes both the crust and the upper mantle and behaves as a brittle, rigid solid, while the asthenosphere, located just below the lithosphere, is partially molten and behaves plastically, allowing it to flow.

Earth's tectonic plates, which are part of the lithosphere, move above the asthenosphere due to the convection currents within the mantle. These tectonic plates can converge at subduction zones, where one plate moves beneath another, leading to mountain building, earthquakes, and volcanism.