Several world-leading scientists believe they have discovered what triggered the Magnitude 9 Great East Japan Earthquake of 2011. After drilling into the Japan Trench, they surmised that the slippery clay in the ultra-thin fault zone caused the earthquake that devastated the region and caused a massive tsunami as well, killing 16,000 and injuring 6,150 in 20 prefectures.
27 scientists from 10 different countries conducted the research in the Japan Trench plate boundary megathrust fault by drilling three holes in the ocean floor and looking at the rupture zone where the tectonic plates from the Pacific and North America meet. The clay is “the slipperiest clay you can imagine” according to geologist Professor Christie Rowe from Canada, comparing it to lubricant. It was because of this substance that it was able to slip through the tectonic plates and travel at faster speeds than that of the normal earthquakes.
But what’s more worrying is that this “deadly clay” can actually cause other similar earthquakes. For example, a similar type is seen in other weak spots in the northwest Pacific crust, from Russia’s Kamchatka peninsula to the Aleutian islands. Another area that contains similar sediments is the Hikurangi Trench in New Zealand up towards Tonga. Kotaro Ujiie, an associate professor at Tsukuba University said that the layer they discovered in that area is about one to five meters thin and is 90% made of low friction clay called smectite. It was originally volcanic ash that was on the surface until it slipped under the plate over a long period of time. Dr Virginia Toy of the University of Otago said that the rock they found in the Japan trench was made of 78% smectite.
[ via International Business Times ]