Take this Quiz: A-Level Geography: Hazards and Tectonics | Zestly

Question 1

In the region of Oakhaven, seismologists record frequent shallow earthquakes along a linear fault line. There is no volcanic activity, and GPS data shows two crustal plates sliding laterally past each other. Which statement correctly identifies the margin and the reason for the lack of volcanoes?

Accepted Answer

This is a conservative margin where the lack of subduction means no crust is destroyed or melted to create magma.

Answer

This is a destructive margin where the absence of subduction prevents the formation of a volcanic arc.

Answer

This is a collision margin where the intense pressure seals the crust, preventing any volcanic eruptions.

Answer

This is a constructive margin where plates pull apart, but the crust is too thick for magma to reach the surface.

Question 2

At the coastal boundary of the Veridian Plate and the Aethelgard Plate, sensors detect both shallow and deep earthquakes. A deep-sea trench is present, and inland, a chain of explosive volcanoes has formed. Which process best explains these observations?

Accepted Answer

Subduction of the denser oceanic plate leads to partial melting of the mantle, creating rising magma.

Answer

Divergence of the plates allows mantle material to rise and melt due to decompression.

Answer

The collision of two continental plates creates massive friction and heat, leading to volcanic activity.

Answer

Transform movement creates enough heat through friction to melt the crust and trigger eruptions.

Question 3

Volcano A has high-viscosity lava and high gas content, resulting in violent eruptions. Volcano B has low-viscosity lava and low gas content, resulting in steady lava flows. What primarily determines this difference in eruptive style?

Accepted Answer

The silica content of the magma, which dictates viscosity and the ability of gases to escape.

Answer

The elevation of the vent, which dictates the pressure exerted on the magma chamber.

Answer

The age of the volcano, where older volcanoes always erupt more explosively.

Answer

The proximity to the ocean, which cools the lava and increases its viscosity.

Question 4

An earthquake of magnitude 6.5 strikes near the town of Stonebridge. Residents on solid granite bedrock report minor rattling, while residents on soft, water-saturated river sediment report significant structural damage. What does this demonstrate?

Answer

The earthquake had two different magnitudes because the energy was absorbed differently by the ground.

Answer

Intensity is a scientific constant, and the damage difference is solely due to poor building quality in the sediment zone.

Answer

Magnitude is a measure of local damage, while intensity is a measure of total energy released.

Answer

Magnitude measures total energy released, while intensity measures the local impact, which is amplified by ground conditions.

Question 5

On a standard logarithmic earthquake magnitude scale, what is the effect of an increase of one whole magnitude step?

Answer

The energy released doubles, and the amplitude of ground shaking remains the same.

Answer

The amplitude of ground shaking increases by a factor of two, and energy release increases by ten.

Answer

The amplitude of ground shaking increases by about ten times, and the energy release increases by a much larger factor.

Answer

Both the amplitude of ground shaking and the energy release increase by exactly ten times.