Here's why:

* Subduction Zones: Convergent boundaries are where tectonic plates collide. In subduction zones, one plate (usually the denser oceanic plate) plunges beneath the other.

* Deep Focus Earthquakes: The descending plate (the subducting plate) is pulled deeper into the Earth's mantle. The immense pressure and heat cause the rocks to become brittle and break, generating earthquakes. These earthquakes can occur at depths up to 700 kilometers (435 miles), much deeper than those found at other plate boundaries.

* Wadati-Benioff Zones: The line of earthquakes associated with subduction zones is called the Wadati-Benioff zone, which slopes down from the trench at the surface to the subducting plate.

Examples:

* The Pacific Ring of Fire, a region with many volcanoes and earthquakes, is characterized by numerous subduction zones.

* The 1960 Valdivia earthquake in Chile, the most powerful earthquake ever recorded, occurred at a subduction zone and had a depth of 600 km (370 miles).

Note: Shallow earthquakes (less than 70 km deep) also occur at convergent plate boundaries, but the deepest earthquakes are uniquely found within subduction zones.