Amazing Earth Facts - V

25. What's the driest place on Earth?

A place called Arica, in Chile, gets just 0.03 inches (0.76 millimeters) of rain per year. At that rate, it would take a century to fill a coffee cup.

26. What causes a landslide?

Intense rainfall over a short period of time can trigger shallow, fast-moving mud and debris flows. Slow, steady rainfall over a long period of time may trigger deeper, slow-moving landslides. Different materials behave differently, too. Every year as much as $2 billion in landslide damage occurs in the United States. In a record-breaking storm in the San Francisco area in January 1982, some 18,000 debris flows were triggered during a single night! Property damage was over $66 million, and 25 people died.

27. How fast can mud flow?

Debris flows are like mud avalanches that can move at speeds in excess of 100 mph (160 kph).

28. Do things inside Earth flow?
You bet. In fact, scientists found in 1999 that molten material in and around Earth's core moves in vortices, swirling pockets whose dynamics are similar to tornadoes and hurricanes. And as you'll learn later in this list, the planet's core moves in other strange ways, too.

29. What is the wettest place on Earth?

Lloro, Colombia averages 523.6 inches of rainfall a year, or more than 40 feet (13 meters). That's about 10 times more than fairly wet major cities in Europe or the United States.

30. Does Earth go through phases, like the Moon?

From Mars, Earth would be seen to go through distinct phases (just as we see Venus change phases). Earth is inside the orbit of Mars, and as the two planets travel around the Sun, sunlight would strike our home planet from different angles during the year. Earth phases can be seen in recent photographs taken by Mars Global Surveyor and the European Mars Express