Zach Wang, Eric Wang, Tom Siitari, & Nick Navarro

 How does gravity play a role in erosion?  What would the advantages and disadvantages be of not having gravitational erosion?

 Steep slopes made from road construction exposes rocks that can eventually fall in a rock fall.  Rocks can go from small sand fragments to large boulders.  Exposed rocks fall due to weathering and gravity.

LLandslides are usually caused by heavy rain, melting snow and earthquakes. AA slump, the most common type of landslide, happens when a mass of material moves downslope on a curved surface. HHeavy rains, deforestation, construction of unstable slopes, and earthquakes increase the chance of landslides.

 Slopes look very firm, but are actually slowly moving in large masses. This slow movement is called creep.  Burrowing animals and water loosen rock and soil particles, so that it slowly slides downhill.

AA large mass of rapid mud is called a mudflow. These are created by water mixing with soil and rock in large amounts. MMudflows are common around volcanoes, because volcano’s give off ash the mudflows are made of. Mudflows can have much power; it can carry cars, trees, houses, and others objects in its way. SSometimes, when the Earth has a vertical drop a sinkhole forms in the ground. Sinkholes can vary greatly in diameter; from several feet to several miles. They can attain depths of 100 feet, or more.

Lahars SSome of the most dangerous mudflows are created by volcanic ash and heavy rain. Lahars are mudflows that have a volcano as an origin. LLahars are classified as hot or cold depending on temperature. There are two things about lahars that make them very dangerous. The fact that they have great velocity and they have great volume. DDebris of old lahars makes future lahars more likely. Some lahars are able to be detected, but most of them catch people completely off guard.  Volcanoes that have snowy peaks, when they erupt they make the snow fall down. When that happens the ice is liquefied and it makes the soil moist; which causes a hot mudflow down the volcano.

HHow does gravity play a role in erosion? IIt causes rocks to move, because they are on mountains/hills, which is considered erosion. WWhat would the advantages and disadvantages be of not having gravitational erosion? AAn advantage is that we would not have these dangerous disasters.  A disadvantage would be that we would have many steep hills.

Credits Nick Navarro: Rock Falls Tom Siitari: Mudflows, Lahars Eric Wang: Creep Zach Wang: Title Page, Landslides, Credits Page Animations Eric Wang(Slides 3-9) Zach Wang(Slides 1-9) Sound Nick Navarro(Slides 1-8) Zach Wang(Slide 9) Q&A Tom Siitari The End