Geology Under the SeaExplore mountains, trenches, volcanoes, and other aspects of the incredible geology of the seafloor. Learn about the Ring of Fire, hotspot volcanoes, and seamounts. Learn about subduction zones (ocean trenches) and earthquakes. A Site Survey Expedition to the Indian Ocean poster In Search of Ancient Lava Flows: A Graphic Novel About a JOIDES Resolution Expedition Learn about seafloor spreading. Learn about subduction zones and mud volcanoes. Learn how ocean spreading centers create a variety of geologic features. What is plate tectonics? What is seafloor spreading? Find out the answers in the: Geology Under the Sea-Drill Down sheet Blog posts about the geology under the sea: The future of Plate Tectonics research Exploring the long lost continent of Zealandia What is a subduction zone? Deep in the Hikurangi Subduction Zone What is a hot spot volcano? Seamount motion in the ocean Volcanoes Many of the JOIDES Resolution expeditions explore the geology of the seafloor.