1. The earth has “plates” and when two plates hit each other, one goes under and becomes “molten” which means it gets so hot, the g ground turns into liquid. The molten stuff finds a hole in the ground and comes out the top.

2. Volcanoes are notorious for their devastating effects, not only on human life but also on the global environment. Lava, emission of toxic gases, ash fall, lahars and landslides are some of the most dangerous hazards of volcanic eruptions Effects of volcanoes

3. The short answer is that earthquakes are caused by faulting, a sudden lateral or vertical movement of rock along a rupture (break) surface. Here's the longer answer: The surface of the Earth is in continuous slow motion. This is plate tectonics--the motion of immense rigid plates at the surface of the Earth in response to flow of rock within the Earth. The plates cover the entire surface of the globe. Since they are all moving they rub against each other in some places (like the San Andreas Fault in California), sink beneath each other in others (like the Peru-Chile Trench along the western border of South America), or spread apart from each other (like the Mid- Atlantic Ridge). Causes of earthquakes

4. Earthquakes have many ways to leave their mark on the land, and most of them are bad. The energy released from an earthquake is 10,000 more powerful than the first atomic bomb. One of the most dangerous effects of an earthquake is a Tsunami. Tsunamis are giant waves that can cause floods and are up to 100 feet tall. They often strike a long way away from the quake, and are very deadly. Another side effect of quakes is fire. The shaking causes broken gas lines. Then all it takes is a spark to start a giant fire. Fire was a big problem in the 1906 San Francisco quake. Effects of earthquak e

5. We know gravity is the ultimate force behind any landslide and that weathering plays a part. But what pulls the trigger to set a slide in motion?gravity Land surfaces are held together by multiple forces. The most important of these is friction. Some soil particles, like clay, cling to each other tightly, while others, like sand, are only loosely joined. All landscapes are held together by friction between the sediment cover and the underlying bedrock, some more tightly than others. If something is introduced to disrupt the friction on an incline, a landslide slips into action. Landslides occur when gravity overcomes the force of friction. Courses of landslides

6. Landslides impeded traffic flow that was diverted onto secondary highways as a result of the collapsed interchange at I-5 and California State Highway 14. Rock falls and rock slides closed many of the alternate routes across the San Gabriel Mountains from the Lancaster/Palmdale and Santa Clarita Valley areas (plate 1) to Los Angeles, and it was several days before some of these routes were cleared of rock debris and made available to commuters. Effects of landslides