Week 2: Volcanic Arch

Question 1

What is The relationship between Visocity and Temperature?

Answer 1

In the above graph, the temperature is plotted against viscosity. As temperature rises viscosity lowers.
For example, if honey is not runny enough you can heat it up and it will pour more easily.
Viscosity → viscosity is a measure of a fluid’s resistance to flow.

Question 2

Where is the largest amount of volcanic rock produced

Answer 2

The greatest amount of volcanic rock is produced at oceanic ridges divergent boundaries.

Question 3

What are stratovolcanoes?

Answer 3

Stratovolcanoes consist of alternating (interbedded) lava flows and layers of pyroclastic debris which reflect relatively gradual and calm and more violent and catastrophic phases of volcano development, respectively.

Question 4

How Do volcanoes Affect the Atmosphere?

Answer 4

Explosive eruptions emit huge quantities of gases and fine-grained debris (particulates) into the atmosphere which filter out and reflect a portion of incoming solar radiation. In the past, volcanic eruptions have led to a period of cooler temperature and a wetter forecast.

Question 5

Explain volcanism at Divergent Boundaries

Answer 5

The greatest amount of volcanic rock is produced at oceanic ridges divergent boundaries.
Lithosphere pulls apart and mafic magma is generated by decompression melting.
Large volumes of pillow basalt are extruded underwater (pillow shape from rapid exterior quenching of lava bodies).
Eruptions are gentle due to low viscosity. And low volatile content.

Question 6

Explain Volcanism at convergent Boundaries

Answer 6

a water-laden oceanic plate is subducted beneath another plate (which can be oceanic or continental).
As the plate descends, it is heated and releases water in the form of vapour.
Water vapour lowers the melting point of rock in the asthenosphere, allowing it to melt into magma. Silica-rich minerals melt first. Eruptions are explosive.

Question 7

Explain Island Archs

Answer 7

Oceanic island arcs are created at ocean–ocean subduction systems. Below the plate melting is triggered, the magma rises and a whole series of volcanoes rise and these are called island arcs. Japan is an example of an island arch

Question 8

Explain Continental Archs

Answer 8

Occurs when one slab of oceanic crust is subducted under the continental lithosphere, a string of volcanoes is produced near the edge of the overriding continent. . The western edge of north and south America is an example