Much like a culmination of three enormous mounds, the culmination of years of research plateaued into Dr. William Sager’s most recent discovery. Until recently, Will Sager (Professor of Geophysics, University of Houston) and his team did not have data to prove that Tamu Massif was a volcano. On seismic ship, R/V Marcus G. Langseth, with reflected sound waves, they were able to collect data verifying that the Tamu Massif was not only a volcano, but the largest submerged volcano in the world. Dr. Sager’s study can be found in the online journal, Nature Geoscience.
Tamu Massif lies a few kilometers under the sea at a plateau known as Shatsky Rise. This is about 1,600 kilometers east of Japan near the northwest Pacific Ocean. As the largest underwater volcano, it reads at 120,000 square miles in area. This implies it could fit almost 2 ¼ times inside the great state of Texas! Despite its sizeable proportions, the volcano is inactive. The largest active volcano on Earth is Hawaii’s Mauna Loa. By comparison, Tamu Massif altogether dwarfs Mauna Loa (only 2,000 square miles). Although the submerged Tamu Massif is big, it is no match for the massive Texas pride that results from the naming of the volcano. The name “Tamu” comes from Texas A&M University, where Dr. Sager previously taught. Tamu Massif distinguishes itself not only in size, but in shape. Its shape could indicate how volcanoes are formed and give insight to the Earth’s interior. Because of its gradual slope, the Tamu Massif resembles a single, continuous shield volcano. In light of this finding, scientists and surfers alike seem only to have more questions. There is still a great deal they have yet to realize.
Scientists now have a whole new class of volcano to factor into their suppositions. Dr. Sager posits how this could influence future knowledge of the ocean: “ […]We knew that oceanic plateaus were large undersea volcanic constructs but did not know how they form. At Tamu Massif, at least, we see one big volcano. This means that scientists who study volcanoes, who study oceanic plateaus, and who study how the Earth's mantle convects, - all must incorporate this type of volcano into their hypotheses. Whatever mechanism they propose must be able to produce a single massive volcano through the outpouring of massive amounts of magma at one spot.” Scientists speculate that the volcano formed closer to the equator. They would be hard pressed to determine if the volcano had bearing on the environment when it was an active underwater volcano. Sager stresses the dampening effect: “Water has a dampening effect on volcanic eruptions deep underwater because it keeps gas in solution in the lava. When the lava gets shallow and the pressure is reduced, it can become explosive. We know of no indication that this volcano had widespread climatic effects. Maybe scientists just haven't spotted those effects yet or maybe they didn't exist. Hard to tell.”
Surfers are curious about how this discovery could guide surf predictions and knowledge of wave generation. Surfers do know that seamounts are largely responsible for some major surf spots around the world (e.g., Hawaii). Significant underwater irregularities like seamounts can be instrumental in how a wave comes into a surf spot. This may cause the surf to be extremely large in one area while nearly nonexistent at a nearby break. For example, Cortes Bank produces a seamount 105 miles off the California coast which yields epic, big waves near Half Moon Bay at Mackericks. Japan has both seamounts and good surf. Located near the “Ring of Fire,” and also across from Tamu Massif, Japan has endured its fair share of disturbing swell generated weather (Typhoons and Tsunamis included). It is hard to shake the coincidence that Shatsky Rise is across from some of the best surfing beaches in Japan. It is possible that there could be surf located near or brought on by Tamu Massif. Again, it is difficult to determine if Tamu Massif could be a direct cause of or link to surf. Notwithstanding its size, Tamu Massif may also be too far from the coastline, too shield-like, and too enveloped with water (wave dampening) to make a significant impact on swell generation (either close by at Shatsky Rise or further towards Japan). On the other hand, reefs and river mouths may be solely responsible for Japan’s world class surfing beaches (e.g., Okinawa).
Scientists do know, however, that Tamu Massif is utterly different from just any old seamount. Dr. Will purports: “There are tens of thousands of common seamounts scattered across the ocean floors. Most are up to 4 km high with basal widths of tens of km and flank slopes averaging 5 deg. Tamu Massif by comparison is much wider (about 450 x 650 km) and has very gentle flank slopes (<1 deg). We think that this has to do with the style of eruption. Normal seamounts erupt pillow basalts, which are like toothpaste coming out in blobs. This occurs at low effusion rates and builds steeper slopes. Tamu Massif seems to have erupted massive lava flows at high effusion rates and these flows traveled long distances at low slopes (<1 deg). We decided to name these volcanoes "massif" which is a term that means an isolated mountain mass. At the time, we did not know that Tamu is one volcano.”
The realization of the largest, secretly submerged volcano will have a massive determination on how scientists proceed with research and how surfers study wave production.
Related info:
Nature Geoscience
Sager, Dr. William. Personal interview. 10 Sept. 2013.
