Agriculture
Protecting Cows—and People—from a Deadly Disease
Microbes at the Gas Pump
Treating peanut allergy bit by bit
Amphibians
Toads
Frogs and Toads
Salamanders and Newts
Animals
Monkeys Count
Not Slippery When Wet
Bee Disease
Behavior
Memory by Hypnosis
Math is a real brain bender
Hitting the redo button on evolution
Birds
Hawks
Swifts
Carnivorous Birds
Chemistry and Materials
Putting the Squeeze on Toothpaste
Bandages that could bite back
Boosting Fuel Cells
Computers
Computers with Attitude
Programming with Alice
Electronic Paper Turns a Page
Dinosaurs and Fossils
An Ancient Spider's Web
Dino Bite Leaves a Tooth
Battling Mastodons
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E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
Earth
Quick Quake Alerts
A Grim Future for Some Killer Whales
Distant Quake Changes Geyser Eruptions
Environment
A 'Book' on Every Living Thing
Island Extinctions
Forests as a Tsunami Shield
Finding the Past
Ancient Art on the Rocks
Of Lice and Old Clothes
Preserving Ancient Warrior Paint
Fish
Piranha
Nurse Sharks
Basking Sharks
Food and Nutrition
Food for Life
A Taste for Cheese
Strong Bones for Life
GSAT English Rules
Who vs. That vs. Which
Problems with Prepositions
Finding Subjects and Verbs
GSAT Exam Preparation Jamaica
Results of GSAT are in schools this week
GSAT stars reap scholarship glory
The Annual GSAT Scholarships
GSAT Exams Jamaica Scholarships
2014 GSAT Results for Jamaican Kids
Access denied - Disabled boy aces GSAT
GSAT Scholarship
GSAT Mathematics
It's a Math World for Animals
How to Slice a Cake Fairly
Prime Time for Cicadas
Human Body
Teen Brains, Under Construction
Gut Microbes and Weight
Germ Zapper
Invertebrates
Camel Spiders
Grasshoppers
Crawfish
Mammals
Sheep
Bobcats
Primates
Parents
What Not to Say to Emerging Readers
How children learn
The Surprising Meaning and Benefits of Nursery Rhymes
Physics
The Particle Zoo
Gaining a Swift Lift
Spin, Splat, and Scramble
Plants
Assembling the Tree of Life
Flower family knows its roots
A Change in Leaf Color
Reptiles
Pythons
Alligators
Crocodilians
Space and Astronomy
Wrong-way planets do gymnastics
An Earthlike Planet
Asteroid Lost and Found
Technology and Engineering
Morphing a Wing to Save Fuel
A Satellite of Your Own
Shape Shifting
The Parts of Speech
What is a Verb?
Pronouns
Countable and Uncountable Nouns
Transportation
Seen on the Science Fair Scene
Where rivers run uphill
Are Propellers Fin-ished?
Weather
Catching Some Rays
Where rivers run uphill
In Antarctica watch the heat (and your step)
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Deep History

The Grand Canyon is one of nature's most majestic and impressive places. The gorge is enormous, measuring 277 miles (446 kilometers) long and up to a mile (1.6 km) deep in some places. The Colorado River runs through the middle of it. But how old is it? Now, scientists have collected new clues about the canyon's ageThe canyon's walls are full of caves that contain lumps of minerals called mammillaries. These mound-shaped lumps usually form just below the surface of pools that are full of minerals. Water levels in such pools can drop when, for example, a change in climate occurs or the Earth's crust shifts. The mammillaries remain, even when the water level drops. Scientists can analyze concentrations of metals inside the mounds to figure out when their pools went dry. Carol Hill, a geologist at the University of New Mexico in Albuquerque, and colleagues studied mammillary formations in nine caves near the Grand Canyon. Most of these caves lie within a few miles of the Colorado River, which carved the rocky gorge. All the sampled mounds were within three-quarters of a mile (1.2 km) above the river's current level. Analyses of the mounds in the western region of the Grand Canyon suggest that 17 million years ago the level of groundwater in the area was about 3,800 feet (1,160 meters) higher than it is today. By 7.6 million years ago, the water had dropped to 3,050 feet above the river's current level. About 2 million years ago, the water was only 390 feet (120 m) higher than it is today. Over that time, water levels dropped as the river carved deeper into the canyon's floor. In the eastern region of the Grand Canyon, analyses suggest that the river's carving action started much later but took place far more quickly. In that area, the groundwater level (and probably the river level) dropped almost as far as it did on the western side, 3,000 feet (920 m), but in only one-fifth the time—just the past 3.7 million years. Together, these data suggest that the Colorado River began carving the Grand Canyon at its western end. Later, the process appears to have continued upstream.—Emily Sohn

Deep History
Deep History








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