Explain the various layers on the earth and its effects on human life.
plese give me a nice answer....
Answers
Answer:
Mountain ranges tower to the sky. Oceans plummet to impossible depths. Earth’s surface is an amazing place to behold. Yet even the deepest canyon is but a tiny scratch on the planet. To really understand Earth, you need to travel 6,400 kilometers (3,977 miles) beneath our feet.
370_crust.png
USGS
A cut-away of Earth’s layers reveals how thin the crust is when compared to the lower layers.
Starting at the center, Earth is composed of four distinct layers. They are, from deepest to shallowest, the inner core, the outer core, the mantle and the crust. Except for the crust, no one has ever explored these layers in person. In fact, the deepest humans have ever drilled is just over 12 kilometers (7.6 miles). And even that took 20 years!
Still, scientists know a great deal about Earth’s inner structure. They’ve plumbed it by studying how earthquake waves travel through the planet. The speed and behavior of these waves change as they encounter layers of different densities. Scientists — including Isaac Newton, three centuries ago — have also learned about the core and mantle from calculations of Earth’s total density, gravitational pull and magnetic field.
Here’s a primer on Earth’s layers, starting with a journey to the center of the planet.
The inner core
This solid metal ball has a radius of 1,220 kilometers (758 miles), or about three-quarters that of the moon. It’s located some 6,400 to 5,180 kilometers (4,000 to 3,220 miles) beneath Earth’s surface. Extremely dense, it’s made mostly of iron and nickel. The inner core spins a bit faster than the rest of the planet. It’s also intensely hot: Temperatures sizzle at 5,400° Celsius (9,800° Fahrenheit). That’s almost as hot as the surface of the sun. Pressures here are immense: well over 3 million times greater than on Earth’s surface. Some research suggests there may also be an inner, inner core. It would likely consist almost entirely of iron.
The outer core
This part of the core is also made from iron and nickel, just in liquid form. It sits some 5,180 to 2,880 kilometers (3,220 to 1,790 miles) below the surface. Heated largely by the radioactive decay of the elements uranium and thorium, this liquid churns in huge, turbulent currents. That motion generates electrical currents. They, in turn, generate Earth’s magnetic field. For reasons somehow related to the outer core, Earth’s magnetic field reverses about every 200,000 to 300,000 years. Scientists are still working to understand how that happens.
The mantle
At close to 3,000 kilometers (1,865 miles) thick, this is Earth’s thickest layer. It starts a mere 30 kilometers (18.6 miles) beneath the surface. Made mostly of iron, magnesium and silicon, it is dense, hot and semi-solid (think caramel candy). Like the layer below it, this one also circulates. It just does so far more slowly.
Answer:
here is the diagram for better understanding.
Explanation:
The cycling of oxygen at the Earth's surface is central to the life and activity that takes place at the surface, but it is equally essential in the Earth's mantle," Kelley said in a statement. "The availability of oxygen to the mantle is in part controlled by the oxygen at the surface."
