the Pacific earthquake and volcano 'ring of fire' made obvious

This detail from a topographic map of the world showing under-ocean ridges and trenches makes the 'ring of fire' around the Pacific Ocean basin quite apparent.  It can be seen that New Zealand straddles two continental plates, while by Japan the ridges and troughs are deep - this was the location of yesterday's massive earthquake. 

Every country in the Pacific near this ring is subject to earthquakes, and there are numerous volcanoes to be found on it.