A new volcanic arc forms at the site of the easternmost transform, and many complications develop in SE Asia (Philippines, etc.) because of transforms turning into arcs, and various subduction-flips as thick (plateau-type) ocean crust refuses to subduct. A new subduction zone develops north of Australia.
Some of the causes of the European voyages of exploration were: 1  Alternate trade routes: Europe was dependent on Middle East countries for the import of spices and was looking for alternate trade routes to Asia and Africa to obtain spices (ginger, nutmeg, clove, cinnamon, etc.) and luxury goods (silk, gold, ivory, etc.) cheaply.
Reasons for exploration. Portugal's long shoreline, with its many harbours and rivers flowing westward to the Atlantic ocean was the ideal environment to raise generations of adventurous seamen. As a seafaring people in the south-westernmost region of Europe, the Portuguese became natural leaders of exploration during the Middle Ages.