Plate Tectonics

See ancient Earth from space

Publication:   Date: April 21, 2011   View Article

Over the past 750 million years, our blue marble has gone through remarkable changes— continents have shifted, ice ages have come and gone, sea levels have risen and fallen, and one-time deserts have turned green, allowing creatures to crawl out of the oceans and live off the land.

These changes are now being made visible by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. The first set of the Visible Paleo Earth visualizations are being released today, on Earth DAy, and more will be available in coming weeks.

8.7 ideas in earthquake prediction

Publication:   Date: April 6, 2009   View Article

Earthquakes are notoriously difficult, if not impossible, to predict. “You are dealing with a very complex physical system that behaves very differently in many places,” says David Schwartz, a geologist with the U.S. Geological Survey’s San Francisco Bay Area Earthquake Hazards Project. Nevertheless, researchers are trying to improve earthquake probability forecasts and working toward, maybe one day, prediction and prevention. Learn about eight of their ideas.

Andes Mountains Jumped Like a Cork

Publication: National Geographic News   Date: June 5, 2008   View Article

After millions of years of slowly being squeezed, warped, and folded higher, the central Andes suddenly shot toward the stars in a geological blink of the eye, according to a new study.

The growth spurt came after chunks of dense, deep rock that anchored the South American mountain range suddenly plopped deeper into the mantle, freeing the buoyant crust to pop up like a cork unleashed from a lead weight.

Nine killer earthquakes

Publication:   Date: April 25, 2008   View Article

Thousands of earthquakes happen every day around the world. Most are hardly felt, if at all. But sometimes pieces of Earth’s crust suddenly slip past each other in a massive release of pent-up stress. The jolted Earth rumbles, buildings collapse, streets buckle, and thousands of people die. These movements are nature’s most violent act and take a grim toll on human life and infrastructure. Learn about nine of the deadliest.

Sea Levels to Plunge Long Term, Study of Dino-Era Says

Publication: National Geographic News   Date: March 6, 2008   View Article

About 80 million years ago—a time when dinosaurs ruled the Earth—global sea levels were roughly 560 feet (170 meters) higher than they are today, according to a new study.

Bay of Bengal Faces Major Tsunami Threat, Study Says

Publication: National Geographic News   Date: September 5, 2007   View Article

Millions of people along the coasts of Myanmar (Burma), Bangladesh, and India may be at risk of suffering a catastrophic tsunami-generating earthquake, according to a new study.

The northern Bay of Bengal could be pummeled by a temblor as massive as the one that sent devastating tsunamis into Indonesia and other Indian Ocean countries in December 2004, the research suggests.

Deep-Sea “Smoker” Vent’s Rumble Reveals Ocean Clues

Publication: National Geographic News   Date: February 8, 2007   View Article

Looks alone suggest that deep-sea vents called black smokers emit a low rumble as they spew scalding, metal-rich fluids from the bowels of the Earth.

And in fact they do, according to the first-ever recordings of the phenomena.

© 2008-2010 Collected Writings By John Roach