What is adiabatic decompression?

(ad-ee-ă-bat -ik) A process that takes place in a system with no heat transfer to or from the system. In general, a temperature change usually occurs in an adiabatic process.

What is upwelling in plate tectonics?

Upwelling mantle melts beneath mid-ocean ridges. The melt ascends and freezes to form the basaltic oceanic crust. Both the basaltic crust and the depleted residual mantle are less dense than the melt source region from which they differentiated. These density changes are large enough to affect plate dynamics.

What is mantle Adiabat?

The Mantle Adiabat Suppose that we take a package of hot, high pressure mantle from deep in the mantle (1) and bring it to a shallower level (2) without letting it exchange any heat with the surrounding rocks.

What does mantle upwelling cause?

More in general, mantle upwelling, following detachment of continental lithosphere, is a likely cause for elevated topography, magmatism and extension in post-collisional belts.

Is there decompression melting at mid-ocean ridges?

Mid-ocean ridge basalts (MORBs) are generated by adiabatic decompression melting of asthenospheric mantle during upwelling as a consequence of passive spreading of the overlying lithosphere.

Does decompression melting only occur at mid-ocean ridges?

Decompression melting commonly occurs at divergent plate boundaries, where two tectonic plates are moving away from each other. Mid-ocean ridges are the classic example, but adiabatic melting also occurs during continental lithospheric extension and in some mantle plumes.

What are upwellings and Downwellings?

Upwelling is a process in which deep, cold water rises toward the surface. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.

What is adiabatic gradient?

Definition of adiabatic gradient : the rate at which the temperature of an ascending or descending body of air is changed by adiabatic expansion or compression, being about 1.6° F for each 300 feet of change of height also : a curve representing this.

What do tectonic plates move due to?

The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another. The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other.

What underlying force drives plate tectonics?

The driving force behind plate tectonics is convection in the mantle. Hot material near the Earth’s core rises, and colder mantle rock sinks.

What is ocean upwelling?

Upwelling is a process in which current s bring deep, cold water to the surface of the ocean. Upwelling is a result of winds and the rotation of the Earth. The Earth rotates on its axis from west to east.

What is artificial upwelling in geography?

Artificial upwelling involves complex technology using the motion of waves to bring cold, nutrient-rich water from the deep ocean to the surface. Experiments in artificial upwelling have been tried in the Pacific Ocean near the Hawaiian Islands. process of bringing cold water from the deep ocean to the surface.

What is upwelling and why does it matter?

Upwelling is a process in which deep, cold water rises toward the surface. This graphic shows how displaced surface waters are replaced by cold, nutrient-rich water that “wells up” from below. Conditions are optimal for upwelling along the coast when winds blow along the shore. Winds blowing across the ocean surface push water away.

What causes coastal upwelling and downwelling?

In any coastal upwelling location, if the winds reverse, surface water moves towards the shore and downwelling is the result. Upwelling can also occur due to geological features of the ocean floor. For example, as deep water currents encounter or other raised features, the water is forced upwards, bringing nutrient-rich water to the surface.