What two plates crashed together to cause the eruption of nevado del ruiz?

Where were the workers from who built the canal? Where are London Docklands in relation to the river Thames? What are the major differences between eastern boundary currents in gyres and the western boundary currents in gyres? How was the structural stability of the CN Tower tested against the forces of wind? Which ocean lies west of Europe? Where is the Nemaha Valley Museum in Auburn Nebraska located? What is the ocean floor part of? What special problems might an animal face if it lives under sand or mud? What is on top of a lighthouse? What continent is bordered by the Atlantic and the pacific ocean? What are the disadvantages of octopus park ride? Munich, Germany? What are rivers in Africa used for? What happened to African captives at the factories along the Atlantic coast? How does the Mississippi change in size from its origin as a small stream at Lake Itasca? Countries in the Mediterranean which do not have the euro? Is the great sphinx the biggest statue in the world? How do wetlands affect water quality in an area? How many buildings are on Alcatraz island? The ocean is an interconnected body of salt water that covers about percent of our planet?