The goddess Pele may be restless again. It seems that the legendary fire-woman, believed by early Hawaiian islanders to live under the sea and breathe lava into the throats of mountains, may be stirring. According to the ancient legends, the chain of Hawaiian islands grew from the northwest to the southeast as Pele episodically pushed through the seas, causing the series of volcanic islands to erupt. Like many myths, this one has some bits of fact – the oldest, extinct, and most eroded volcanoes are in the northwest, right where the legend says Pele began her work. Today, they say, she is busy under the world’s largest mountain, Mauna Loa, on the big island, which is also the world’s most active volcano.
Canadian geophysicist Tuzo Wilson saw things in a similar way. Back in the mid-1960s, when plate tectonics was finally taken seriously, it was apparent that volcanoes could occur at plate boundaries – the crust was fragmented and friction from the rubbing plates was heating things up, said advocates of the nascent theory. But there were too many examples of volcanic activity far from plate edges. This cast some doubt on plate tectonics, as opponents to drift quickly pointed out. Tuzo Wilson then revealed his dream (I would call it a nightmare.) of the goddess Pele on the bottom of a river, staring up, blowing bubbles from her mouth. The bubbles rose to the surface and, according to Tuzo’s vision, left a trail on the water’s surface. Professor Wilson said this image made him think of a mechanism for volcanoes that occur far from tectonic plate edges. The river is the ocean’s moving crust, Pele is a hot spot, and her exhaust is a mantle plume. Thus plume theory, an auxiliary to plate tectonics was born.
Tuzo Wilson tried, unsuccessfully, to publish his idea in “the leading American geophysics journal.” His revolutionary idea was rejected by the reviewers. Silly and daffy, they must have thought. Wilson quickly submitted his paper to a Canadian physics magazine. The Canadian Journal of Physics published “A Possible Origin of the the Hawaiian Islands” in March 1963. The paper’s editors accepted it because “they didn’t realize it was controversial” said Wilson. Perhaps. But they likely published Wilson’s work because the 55-year-old scientist (known to his friends as the cyclone) had a formidable reputation for clever insights in geology. He was a mountain climber, a travel writer, and one of the first to pilot an aircraft over the north pole. He pretty much invented aerial geology and was well-known as man who seldom got things wrong. He was not the first to support plate tectonics, but he was an early and fervent proponent – once he recognized the bulk of evidence sided with the theory. He was in his mid-50s when he abandoned stationary continents in favour of mobile ones. Very few scientists can make such a leap in ideology and embrace a new theory – and then make major contributions to the hypothesis. (In another posting, I’ll come back to Tuzo Wilson and describe his invention of transform faults and his creation of the idea of a repeatedly opening and closing Atlantic Ocean, now called Wilson Cycles. Plumes, Transform Faults, and Wilson Cycles are integral to plate tectonics.)
Mauna Loa is quite a structure. Pele has constructed a mountain that rises almost 4200 metres above the sea. From the Pacific seafloor to its snowy peak, the mammoth mountain is actually over 9200 metres – making it somewhat taller than Everest. A broad shield volcano, the mountain is 60 miles long and 30 miles wide. It is huge. And formerly, quite active – spewing lava every few years for thousands of years. However, the volcano has been quiet for the last 30 years. Until this spring. Earthquakes are waking cobwebbed seismometers, foretelling the next blast. Volcanologists believe it may be imminent.
Read the book, The Mountain Mystery.