which sits at the leading edge of the giant Indo-Australian
Plate, moves in a northeasterly [right] direction.
In so doing it collides with the western edge of the
Philippine Plate. This collision pushes up the ocean
floor above sea level, creating island chains, island
arcs, and a twisted, tumultuous sea floor .
The Pacific Plate, moving northwest,
subducts under the eastern edge of the Philippine
Plate. This area of subduction is a hotbed of volcanic
and earthquake activity and part of the infamous "Ring
of Fire." You can see a mid-ocean ridge to the
south of Australia, the site of sea-floor spreading.
New Zealand, to the southeast, exists along this complex
Thanks to Bruce Heezen and Marie Tharpe.