Question

Convection occurs in two main regions of Earth’s interior: the outer core and the asthenosphere, which is part of the mantle. Describe one similarity between these two layers. Describe two significant differences.

Answer 1

Answer:

• Mantle convection is the very slow creeping motion of Earth's solid silicate mantle caused by convection currents carrying heat from the interior to the planet's surface. The Earth's surface lithosphere rides atop the asthenosphere and the two form the components of the upper mantle.
• The mantle is the mostly-solid bulk of Earth's interior. The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust.
• Convection currents in the magma drive plate tectonics. Heat generated from the radioactive decay of elements deep in the interior of the Earth creates magma (molten rock) in the aesthenosphere. The aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the Earth that extends to 2900 km.
• Heat flows in two different ways within the Earth: Conduction: Heat is transferred through rapid collisions of atoms, which can only happen if the material is solid. Heat flows from warmer to cooler places until all are the same temperature. The mantle is hot mostly because of heat conducted from the core.
• Mantle convection is the process by which the excess heat in the Earth's deep interior is transferred to its surface through the fluid-like motions of the rocks in the mantle.
• The Earth's core is cooling down very slowly over time. ... The whole core was molten back when the Earth was first formed, about 4.5 billion years ago. Since then, the Earth has gradually been cooling down, losing its heat to space. As it cooled, the solid inner core formed, and it's been growing in size ever since.