The Japanese archipelago is in a subduction zone with great tectonic plate movement. The Philippine Sea Plate moves beneath the continental Amurian Plate and Okinawa Plate to the south. The oceanic Pacific Plate moves under the continental Okhotsk Plate to the north. These subduction plates have pulled Japan eastward and opened the Sea of Japan by back-arc spreading around 15 million years ago. It has uplifted the Japanese islands and created three oceanic trenches: the Kuril–Kamchatka Trench, Japan Trench and Izu-Ogasawara Trench. This has produced a wide variety of mineral resources, though not in large quantities on-shore. Most resources are in the seabed.