Where are the largest volumes of andesite lava usually extruded?

The largest volumes of andesite lava are typically extruded in regions where oceanic lithosphere is subducting beneath continental crust. This geological process occurs at convergent plate boundaries, where an oceanic plate is forced down into the mantle beneath a continental plate. As the oceanic plate descends, it undergoes partial melting due to increasing temperatures and pressure, which generates magma that is richer in silica compared to the basaltic magma primarily produced at mid-ocean ridges.

Andesite, characterized by its intermediate composition, forms as a result of this melting process and is commonly associated with explosive volcanic eruptions. These eruptions often create composite volcanoes, also known as stratovolcanoes, which are prevalent in volcanic arcs that form along subduction zones, such as the Andes mountains in South America.

In contrast, locations such as oceanic ridges are primarily sites of basaltic lava extrusion, while regions where continental crust is breaking apart tend to produce more basalt and rhyolite. Volcanic hotspots can produce a range of magma compositions but predominantly generate basaltic lava, as seen in shield volcanoes like those of Hawaii. Thus, subduction zones are specifically designed to produce the significant volumes of andesite lava, making this the correct answer.