Agriculture
Where Have All the Bees Gone?
Middle school science adventures
Growing Healthier Tomato Plants
Amphibians
Poison Dart Frogs
Toads
Tree Frogs
Animals
Monkey Math
Fishy Cleaners
Big Squid
Behavior
Swedish Rhapsody
The Colorful World of Synesthesia
Storing Memories before Bedtime
Birds
Cardinals
Robins
Swifts
Chemistry and Materials
Makeup Science
Music of the Future
A Light Delay
Computers
A Classroom of the Mind
Look into My Eyes
Supersonic Splash
Dinosaurs and Fossils
Dino Flesh from Fossil Bone
Ancient Critter Caught Shedding Its Skin
Battling Mastodons
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
Earth
Weird, new ant
Ice Age Melting and Rising Seas
Bugs with Gas
Environment
The Wolf and the Cow
An Ocean View's Downside
Sea Otters, Kelp, and Killer Whales
Finding the Past
Words of the Distant Past
Watching deep-space fireworks
Of Lice and Old Clothes
Fish
A Jellyfish's Blurry View
Sting Ray
Marlin
Food and Nutrition
Turning to Sweets, Fats to Calm the Brain
Chocolate Rules
Packing Fat
GSAT English Rules
Order of Adjectives
Pronouns
Whoever vs. Whomever
GSAT Exam Preparation Jamaica
Scotiabank Jamaica Foundation Grade Six Achievement Test (GSAT) Scholarships
GSAT stars reap scholarship glory
Ministry of Education Announces 82 GSAT Scholarships for 2010
GSAT Exams Jamaica Scholarships
GSAT stars reap scholarship glory
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Exam Preparation
GSAT Mathematics
A Sweet Advance in Candy Packing
Math and our number sense: PassGSAT.com
Secrets of an Ancient Computer
Human Body
Music in the Brain
Hey batter, wake up!
Spit Power
Invertebrates
Horseshoe Crabs
Black Widow spiders
Giant Clam
Mammals
Rats
Hoofed Mammals
Aquatic Animals
Parents
What Not to Say to Emerging Readers
The Surprising Meaning and Benefits of Nursery Rhymes
Children and Media
Physics
Einstein's Skateboard
Thinner Air, Less Splatter
Spin, Splat, and Scramble
Plants
Fungus Hunt
Fast-flying fungal spores
A Giant Flower's New Family
Reptiles
Iguanas
Lizards
Sea Turtles
Space and Astronomy
Supernovas Shed Light on Dark Energy
A Dead Star's Dusty Ring
A Moon's Icy Spray
Technology and Engineering
Switchable Lenses Improve Vision
Musclebots Take Some Steps
Shape Shifting
The Parts of Speech
Pronouns
What is a Preposition?
Adjectives and Adverbs
Transportation
Morphing a Wing to Save Fuel
Ready, unplug, drive
Charged cars that would charge
Weather
The Best Defense Is a Good Snow Fence
A Change in Climate
In Antarctica watch the heat (and your step)
Add your Article

Earth Rocks On

Most of the time, the ground feels solid beneath our feet. That's comforting. But it's also misleading because there's actually a lot going on underground. Masses of land (called plates) slip, slide, and bump against each other, slowly changing the shape of continents and oceans over millions and billions of years. Scientists know that Earth formed about 4.5 billion years ago. They also know that our planet was hot at first. As it cooled, its outermost layer, called the crust, eventually formed moving plates. Exactly when this shift happened, however, is an open question. Now, an international group of researchers has an answer. They've found new evidence suggesting that Earth's crust started shifting at least 3.8 billion years ago. The new estimate is 1.3 billion years earlier than previous ones. Not long before 3.8 billion years ago, lots of asteroids were pummeling Earth, keeping its crust in a hot, molten state. After the hard crust formed, much of it sank at various times into the planet's hot insides. There, it melted before returning to the surface as lava. In some places, however, the crust never sank. One of the oldest such places is in Greenland, in an area called the Isua supracrustal belt. The rocky crust there is between 3.7 and 3.8 billion years old. The belt was once part of the seafloor, but now it is exposed to air. The researchers recently took a close look at the Isua supracrustal belt. They noticed long, parallel cracks in the rock that have been filled in with a type of volcanic rock. To explain this structure, the scientists propose that tension in the crust caused the seafloor to crack open long ago. Hot, liquid rock, called magma, oozed up from deep inside Earth to fill the cracks. Finally, the whole area cooled, forming what we see today. That explanation, plus chemical clues inside the rock, suggests that the Isua supracrustal belt was once part of a plate under the ocean, beginning around 3.8 billion years ago. "It's a marvelous case of solving a jigsaw puzzle," says one of the researchers, Gustaf Arrhenius of the Scripps Institution of Oceanography in La Jolla, Calif. He notes that the puzzle was "a very difficult one because these rocks are all very old and have been badly mangled."E. Sohn

Earth Rocks On
Earth Rocks On








Designed and Powered by HBJamaica.com™