![]() ![]() ![]() Both our graphic and the BBC’s “Journey to the Center of the Earth” note the Mohorovicic discontinuity and the Gutenberg discontinuity.Divers often incorporate helium into their tanks of breathing gas in mixtures known as trimix (which mixes oxygen, helium, and nitrogen) and heliox (which mixes oxygen and helium). Although nitrogen and oxygen have narcotic effects at high pressure, helium doesn’t.effects on the brain, collectively known as nitrogen narcosis.” All that extra nitrogen rushing round in the bloodstream has. When you dive deep underwater, the increase in pressure exerted on your body by the surrounding water causes more of these gases to dissolve into your blood through your lungs when you breathe from the gas tank (because going deep-sea diving without a gas tank would be an even less recommendable thing to do). Several gases, including nitrogen, carbon dioxide, and oxygen are normally dissolved in our bloodstream. However, a problem arises when we breathe it in under high pressure-such as when diving. Here’s a great explanation: “Above sea level, nitrogen is a pretty boring gas-it makes up about 80% of the air around us and doesn’t normally do us any harm. Nitrogen narcosis is the result of breathing gases under high pressure.People living and working at the same depth in solid ground don’t experience this phenomenon. At about 10 meters (33 feet), the graphic starts to note how divers may experience “nitrogen narcosis,” a phenomenon similar to alcohol intoxication. The BBC graphic drills deep into the earth and dives deep into the ocean to show “what lies beneath” the surface. ![]() At this scale, you can move through the entire core in one swipe! Toward the center of the Earth, one pixel represents 2,500 meters (2.5 kilometers).At the deepest place yet reached by people ( hi, James Cameron!), one pixel represents one meter.That leaves a lot of room for information about drilling, diving, and metal detectors. Near the surface of the Earth, one pixel represents about.As you scroll down, you can see the scale going from large-scale to small-scale. Take a look at the bottom of the “Journey to the Center of the Earth” interactive graphic.(Just remember: large-scale map=small details.) ( Learn more about scale with this activity.) Large-scale mapping allows much greater detail than small-scale mapping. Scale is the relationship between distances shown on a map and actual distances in the real world. Scale! Scale is one of the most important concepts in mapping.Just the opposite is true in our own illustration of Earth’s interior, which shows the upper and lower mantle-not the crust-as the thickest layer in Earth’s interior. Scrolling through the fantastic BBC interactive graphic of Earth’s interior, it seems like the crust takes up a lot more room than the mantle or core.Illustration by Mary Crooks, National Geographic The Earth is divided into three main layers: the dense, hot inner core (yellow), the molten outer core (orange), the mantle (red), and the thin crust (brown), which supports all life in the known universe. Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit. (BBC)ĭownload our own high-resolution illustration of Earth’s interior. How far would you have to travel to reach the Earth’s core? And what would you see along the way? Use this interactive to dig into the truth. ![]()
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