Subduction Zones

Alan Feuerbacher

Subduction zones are areas where one tectonic plate plunges beneath another. Earthquakes cluster at the edge of the plunging plate, and its path into the mantle can be traced by the location of the earthquakes. The "ring of fire" around the Pacific is a giant earthquake zone, and coincides with a ring of subduction zones that produces the world's deepest trenches, such as the 36,000 foot deep Marianas Trench. It is striking evidence for the existence of these zones. So also is the fact that great chains of explosive volcanoes that form some island arcs, such as the one including Krakatau, occur along the edge of trenches. ".... the plate-edge volcanoes lie above great rising curtains of magma that parallel the trench marking the interface between two colliding plates."128

Seismic images, made by bouncing sound waves off rock layers under the sea floor and recording the reflections with an array of detectors, show the existence of subduction zones directly. The smooth sediment layers lying well out into the ocean, the pile-up of sediments at the edge of a continental plate where the oceanic plate plunges beneath it, and the descent of the edge of the oceanic plate beneath the continental plate can be clearly seen in such images.129 Deep drilling into these layers confirms the rock structure inferred from the seismic images. Since the descent of one plate under another can be clearly seen from seismic images, and the rock layering is still intact, the ocean basins could not sink within the one year allotted by the Society's Flood chronology. The rocks would be so broken up that seismic images would show only a blur.

The above information shows how the great trenches are produced -- they are simply the result of the plunging plate of necessity being deeper than the one under which it plunges. The trenches do not suddenly open, but take a long time to form.

All the information I've presented on plate tectonics shows that the ocean basins did not form by sinking in place. They formed by the process of seafloor spreading, which takes a great deal of time. The statement in the God's Word or Man's book on page 113 that it "is quite likely that -- perhaps triggered by the Flood itself -- the plates moved, the sea bottom sank, and the great trenches opened, allowing the water to drain off the land," demonstrates the writer's ignorance of the geological processes involved. The sea bottom did not suddenly sink. The trenches did not suddenly "open" -- they have existed for as long as oceanic plates have subducted under other plates.

It is difficult to conceive how all the geological phenomena so clearly explained by plate tectonics can alternatively be explained by a universal Flood, especially within the 48,000 year creative week chronology given by the Society. I presume the Society would not accept an explanation as in an anecdote where a little old lady, upon visiting Dinosaur Monument in Utah and being asked how she thought the buried dinosaur skeletons got there, replied that "the Lord put them there to fool you."

The Society has been strangely silent on the matter of plate tectonics. Except for one excellent summary of the subject, which appeared in the June 22, 1977 Awake!, I've not found any other significant references. Is the Society just ignoring the evidence, hoping no one will notice?


128 David G. Howell, "Terranes," Scientific American, p. 118, New York, November, 1985.

129 John C. Mutter, "Seismic Images of Plate Boundaries," Scientific American, New York, February, 1986.