Final answer:
Deep earthquakes at convergent margins occur at depths ranging from 70 km to 700 km below the surface, increasing in depth from the coastline inward, corresponding to the angle of subduction.
Step-by-step explanation:
Deep earthquakes at convergent margins typically occur within the range of 70 km to 700 km below the Earth's surface. In subduction zones, where one tectonic plate is forced down into the mantle beneath another plate, the descending slab can generate deep earthquakes.
The depth of these earthquakes generally increases from the coastline towards the interior following the angle of subduction. The exact depth can vary based on the subduction angle; steeper angles often lead to deeper earthquakes. Volcanoes at convergent margins can also be closely related to the depth of the subducting slab, often forming where the slab reaches sufficient depth to induce partial melting of the asthenosphere.