Shawna Vogel is a popular science author and associate director of the Office of Sponsored Programs at Massachusetts Institute of Technology (MIT). Her previous occupations include principal at Lantana Consulting, executive director of the Center for Regenerative Medicine at Massachusetts General Hospital, technology licensing officer and Knight Science Journalism Fellow at MIT, and associate editor of Discover Magazine. She has also written for Scientific American and Earth magazines.
Naked Earth: the New Geophysics (1995)Edit
- Don Anderson... realized that since heat conducts only half as quickly through continental crust as through oceanic crust, the former acts like an insulating blanket. A mass as large as a supercontinent would cause the mantle to grow hotter, which would affect circulation. ...To Anderson's eye, the cluster of hotspots and the bulge in the earth exactly beneath the former site of Pangaea not only broke up the supercontinent but were formed precisely because it was preventing heat from getting out.
- The crust and mantle churn together on both the yearly scale of incremental plate motions and the epochs of supercontinental cycling.
- Early in the last century, the most powerful earthquakes ever to strike the stable heart of the continent rattled the Reelfoot Rift.
- As James Lal Penick has documented in his The New Madrid Earthquakes... These "sand blows" erupted with a loud bang and then a roaring whistle like the shrill of a desert sandstorm.
- Paleoseismology... is science by backhoe. Researchers dig deep, straight-walled ditches and search up and down for signs of shaking.
- Because these earthquakes strike in the strong, unfractured rock of plate interiors, their tremors travel faster than those of border quakes before petering out. ...The possibility of such a mid-plate quake thus carries a much higher risk than one on a plate boundary.
- Like a cracked china cup, the continental crust is still fragile where it has been damaged in the past.
- Oceanographer Edward Baker and his colleagues... came across a startling anomaly. ...something peculiar: a football-shaped mass of warm water some twelve miles across and nearly half a mile from top to bottom. ...a half a degree warmer than the surrounding sea water. ...18 billion kilowatt-hours of energy ...The researchers dubbed this feature a megaplume.
- According to Woese's evolutionary tree, the most primary of the present-day bacteria lie within a group called the archaebacteria. All archaebacteria thrive in intense heat... Woese believes that that these modern species evolved from a similar type of ancient bacteria that... may have drawn its energy from the sulfurous compounds spewing out of hydrothermal vents. If that's true, the bacteria seen at vents today could be the closest descendents we know of the original forms of life on earth.
- In geophysical circles, the question is not so much why the sea is salty, but why it remains just as salty as it is, no more, no less.
- The ocean crust serves as a global water-treatment plant. Salts are removed, PH is balanced, and various minerals are added as the water continuously flushes through the crust and out the vent stacks. According to one estimate, the entire ocean passes through this filter once every ten million years.
- Through the burps of megaplumes and the steady puffing of hot, chemically altered water through the ocean crust, the earth concentrates its stores of precious metals. ...Such a store exists within the Troodos Massif, a...phalanx of mountains on the island of Cyprus. ...This heap of rock eventually became one of mankind's earliest sources of copper, the metal that took its name from Cyprus. ...Out of the ocean rose precious metals, out of the Stone Age rose civilization.
- The dynamic earth has been spewing out the constituents of evolution and progress throughout its history, nurturing all species from the very first forms of life to our own.
- Researchers believed that sulfur dioxide emitted by volcanoes would turn into sulfuric acid in the stratosphere, creating a haze of acid droplets that would block the sun's rays and keep them from warming the air below.
- This nagging dilemma has come to be known as the excess sulfur problem... Just as atmospheric scientists were beginning to grasp the importance of a volcano's sulfur emmisions, solid earth scientists were finding that they had no idea where all this sulfur was coming from.
- The one known fingerprint of a sulfurous volcano is a compound called anhydrite, which dissolves in groundwater. Just a few years after an eruption... all traces of anhydrite are gone. This explains why the substance had pretty much eluded scientists before it was discovered at El Chichón.
- Even in comparison to out sister world [Venus], our home planet is exceptional.
- As instruments of global climatic change, we humans now rival such cataclysmic events as supercontinent breakups and asteroid impacts.
- Our tenancy on this planet is not guaranteed.