Answer: The Pacific ‘Ring of Fire, or Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes. This is home to more than 450 active and dormant volcanoes (75% of Earth’s total volcanoes). However, there are other significant areas, such as the Mid Atlantic Belt, Alpide Belt, East African Rift, where volcanoes are also concentrated. 

Volcanism across major plate boundaries - A comparison: 

Reasons for disproportionately large number of volcanoes in Pacific Ring of Fire: 

• Plate movements: Pacific Plate exhibits ocean-ocean, ocean-continental convergence which involves major subductions, and formation of transform boundaries results in intense volcanic activity. On the other hand, other major plate movements, such as continental-continental collisions or divergent boundaries, do not involve extensive subduction, leading to fewer volcanoes.
• Tectonic Plates: The Pacific Ring of Fire is located at the junction of several tectonic plates, including the Pacific, North American, Eurasian, Philippine, and Australian plates. The movement of these plates causes frequent earthquakes and volcanic eruptions. 
• Subduction Zones: The region is also characterized by subduction zones, where one tectonic plate is forced beneath another. This process generates magma, which can lead to volcanic eruptions.

• Nazca Plate subducts beneath the South American Plate- Andes Mountains include the world’s highest active volcano, Nevados Ojos del Salado.

• Volcanic Arcs: The subduction of oceanic plates beneath continental plates can create volcanic arcs, where magma rises to the surface and forms a chain of volcanoes. 

• For example, the Aleutian Islands in Alaska run parallel to the Aleutian Trench. 

• Plate Speed: The relatively fast speed of the Pacific Plate (faster subduction -> higher intensity and frequency of volcanoes) contributes to the concentration of volcanoes in the Pacific Ring of Fire, as compared to other regions where plate movements may be slower.
• Hotspots: The Pacific Ring of Fire also includes several volcanic hotspots, such as Hawaii and Yellowstone. These areas are characterized by high heat flow and magma production, which can lead to volcanic activity.
• For example, Mount Erebus, the most southern active volcano on Earth, sits over the eruptive zone of the Erebus hot spot in Antarctica. 

The Ring of Fire has been responsible for many of the world’s most catastrophic volcanic eruptions and earthquakes and has affected many densely populated areas around the Pacific region. However, on the other side, the volcanic activities have provided many valuable resources, such as rich farmland and the possibility of tapping geothermal activities for heating and electricity.