ANSWER

• INTRODUCTION – WHAT IS CIRCUM- PACIFIC ZONE
• BODY - GEOPHYSICAL CHARACTERISTICS
• A BRIEF CONCLUSION

Circum-Pacific zone is the

• Path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes
• Region encompassing the coast of Asia, Australia, and Americas
• Stretches from Bering strait in Siberia to New Zealand and coast of Chile to Alaska
• Geophysical characteristics of Circum-Pacific Zone

FEATURES

Formation

• This Circum-Pacific chain of volcanoes (often called the Ring of Fire) and the mountain ranges associated with it owe their formation to the repeated subduction of the oceanic lithosphere beneath the continents and the islands that surround the Pacific Ocean.
• The Ring of Fire is the result of plate tectonics (Convergent, Divergent Plate Boundary, Transform Plate Boundary).

Harbors Majority of Volcano & Earthquakes

• Seventy-five percent of Earth’s volcanoes—more than 450 volcanoes—are located along the Ring of Fire.
• Ninety percent of Earth’s earthquakes occur along its path, including the planet’s most violent and dramatic seismic events.

Archipelago clusters

• Archipelago is a group of many islands in a large body of water
• It is basically oceanic islands which are a chain, cluster or collection of scattered islands
• The Circum-Pacific zone consists of clusters of archipelago such as Japan, Philippines, Indonesia, Polynesia, Chile etc.

Trenches

• Oceanic trenches are topographic depressions of the seafloor, relatively narrow in width, but very long. These oceanographic features are the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year.
• A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc.
• The edges of plates are destructive boundaries and as a result large trenches are found. They include Mariana trench, Guam trench etc.

Hot Spots

• The Ring of Fire is also home to hot spots, areas deep within the Earth’s mantle from which heat rises.
• This heat facilitates the melting of rock in the brittle, upper portion of the mantle. The melted rock, known as magma, often pushes through cracks in the crust to form volcanoes.