Examine the map above and answer the following questions: (i) What is the name given to the region from X1, along the shaded line, to X2? (ii) Name the ridge running north from Y - Leaving Cert Geography - Question Question 1 - 2011

The ridge running north from Y is called the Mid Atlantic Ridge. This underwater mountain range is a divergent boundary between tectonic plates.

1. Mount St. Helens (Located in Washington, USA)

2. Krakatoa (Located in Indonesia)

Both of these volcanoes are well-known for their significant eruptions in history.

1. Pacific Plate

2. North American Plate

These plates play a major role in the tectonic activity in the Pacific region.

Subduction is the geological process where one tectonic plate moves under another and sinks into the mantle. This often occurs at convergent boundaries and can lead to the formation of deep ocean trenches and volcanic arcs. It involves two primary processes:

1. Oceanic Crust Subduction: The denser oceanic plate is forced under a less dense continental plate, leading to volcanic activity.
2. Plate Movement: As the subducting plate descends into the mantle, it melts and causes magma to rise, resulting in volcanic eruptions.