Japan's Maruyama Shigenori, one of the world's leading geophysicists, is working on a global formula for a new field of study that would include dozens of disciplines collaborating to produce an overall picture of the Earth. As he connects the links from astronomy to life sciences, an outline emerges of an all-encompassing image of entire planets which appear as living super-organisms.
Shigenori believes that expanding the study of life sciences to the core of our world and the depths of outer space will help us find distant relatives of our own Earth -- planets that could also sustain life.
Maruyama is creating a new institute called the Center for Bio-Earth Planetology will be launched in 2009 and fully dedicated to creating a new conception of life in space.He wants to find out if the continents will merge again in 250 million years to form a single super-continent; how meteorites change the chemical composition of the Earth; and what the connection is between the temperature of a planet and its magnetic field, which protects plants and animals from being bombarded with cosmic radiation, which in turn influences the rate of mutations and thus the development of new forms of life.
Maruyama is also provoking controversy in the with his new theory on the lifecycle of the Earth's crust.
To explain why contintental plates drift on the surface of the Earth's molten mantle, Maruyama argues that continents actually have life cycles. Old, cold plates on continental fringes sink to “plate graveyards” deep in the Earth’s mantle, and then rise again, creating volcanoes fueled by three-dimensional convection movements deep below the surface.
Maruyama is taking the ideas of continental-drift pioneer Alfred Wegener to a new level. Wegener was a German explorer and meteorologist who believed back in 1912 that the continents roamed about on the surface of the Earth -- an idea that was ridiculed by even his most supportive research colleagues as a "delirious vision" and "the wonderful dream of a great poet." It wasn't until the 1960s that studies of the ocean floor finally provided irrefutable proof that Wegener had been right after all.
Today, we all know that the continents are enormous plates that drift on the Earth's red-hot mantle like icebergs on the ocean. Yet to this day, the hypothesis still lacks a logical and convincing foundation. Nobody has been able to explain the actual mechanics behind the motor that drives the drifting and breaking-up of the continental plates.
The inner reaches of the Earth remain shrouded in mystery. Even the surface of has been explored more extensively. Because deep drilling comes to a halt after a maximum of 12 kilometers, the remaining 6,300 kilometers to the center of the Earth remain inaccessible.
In an interview with Der Spiegel, Maruyama gave the answer: "The continental drift that we observe on the surface of the Earth has its counterpart in the Earth's mantle. Old, cold plates are pushed down into the Earth's mantle on the continental edges," he explains. "At this point they collect large amounts of iron. You can imagine it as something similar to water condensation."
Weighted down by the iron, the plates sink farther and farther into the hot, molten rock until they reach the inner sanctum of the Earth's mantle. There, at a depth of 2,900 kilometers, they finally halt their decent and settle into "plate graveyards." This is presumably the outer edge of the earth's heavy core, where the temperature is 4,000 degrees Celsius (7,200 degrees Fahrenheit).
Maruyama continues: "But the capsized continents don't simply rest in their plate graveyards forever." Rather, they are about to experience a sudden resurrection. Heat and pressure in the depths trigger chemical processes, causing the plates to deposit their load of heavy elements. Once liberated of this burden, they become lighter than their surroundings, causing them to rise like corks in water. The result: Above the old plate graves, on the floor of the Earth's molten mantle, a mushroom-shaped upwelling of abnormally hot magma called a mantle plume makes its way toward the surface.
Eventually, the rising flow of molten rock reaches the crystallized crust and cuts through it like a welding torch. Volcanoes form, such as those on the Big Island of Hawaii.
Maruyama says the red hot lava that erupts on the volcanic island comes directly from an old plate cemetery 2,900 kilometers below the surface, where the remains of an ancient continent that broke up some 750 million years ago simmer to the surface. Maruyama's theory postulates the amazing comeback story of this ancient rock from the deep.
The key ingredient for the chemistry of the Earth's interior is the same one that determines the weather on the surface: water. The sunken ocean plates have old seawater locked in their mineral structure -- only a few parts per thousand, but enough to drastically change the characteristics of the rock.
Even minute quantities of water in the ex-floor of the ocean can significantly lower its melting point -- and this speeds up its eventual return to the surface. The water helps the rock to lose its load of heavy iron, thereby increasing the buoyancy of this old plate material.
The geophysicist thus paints a three-dimensional picture of the planet Earth where, in addition to the continents drifting on the surface, there is room for "anti-plate tectonics" at the base of the Earth's mantle. An "anti-crust" deep below reflects to a certain degree events on the surface, with "lakes" and "mountains" and "rivers" of viscous molten rock.
Earthquakes and computing power are the main requirements for researchers looking to piece together an x-ray-like image of the Earth's interior. The principle is simple enough: When an earthquake strikes, the seismic waves race clear across the Earth's mantle. It takes a full quarter of an hour for the shockwave to travel from Indonesia to Germany. The duration of this journey reveals a great deal to researchers. The waves are slowed down by viscous and hot regions, like mantle plumes, and accelerated by solid or cold objects.
Earthquakes similar to the one that hit Kobe in 1995 and killed nearly 5,100 Japanese -- are Maruyama's main source of data. The island nation lies directly on the West Pacific crossroads of three huge plates that ram into each other like cars in a highway pile-up: the Pacific, Australian and Eurasian tectonic plates.
Posted by Casey Kazan.