ENV-SCI 110R 1st EditionExam # 2 Study Guide 2/16Average test score was 75% Highest score was a 96%Zone of subduction: where a continental plate and a oceanic plate meet, and the continental plate pushes the oceanic plate down into the mantle. The melting point in the bottom plate lowers so more rock becomes liquid in the mantle. Cracks beging to develop in the continental plate. Creates a lot of pressure and mantle is pushed through the cracks creating volcanoes. Likethe Andes, the Rocky mountain range all the way from Canada through the united states and the Ilushian islands that are a part of Alaska, and the ring of fire. They are a huge line of mountainous volcanoes. Himalayas are NOT the subduction. They are crushed together and pushed upwards. Crusts can be recycled by erosion. It is carried by rushing water down The plate that Australia and India are on is drifting north west and also turning. So this plate is pushing up against the Eurasia plate. This causes the Himalayas to grow taller. Sometimes, two continential plates will drift together and stop moving. They do not move after that and somewhat become formed together. This is called suture. This is on the western side ofRussia by Europe. The Appalachian mountains are in the middle of the north American plate, but they are from previous plates pushing against each other.Fault: sliding (transverse fault) or movement of plates. San Andreas fault: somewhere in California. Lots of earthquakes. Not crazy, but just a little bit ofmovement for a release of pressure. Tsunami: pacific plate moves towards the north west. Being subducted under the northern plateof japan. The edge of the continential plate is being pulled down into oceanic plate because of all the friction. It is not being subducted like the oceanic plate, but is being pulled down. Finally, the continential plate flips back up and creates an earthquake. The sudden impact forces the water away from the coast and creates a huuuuge wave away from the coast. The water is pulled away from the shore and then rushes back in and smashes against the coast in a Tsunami.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Most earthquakes are in the zones of subduction. They keep track of these earthquakes with the Richter scale. This scale is not a arithmetic scale. For example, an earthquake of 6 is 32 times more powerful than an earthquake of a 5. The midatlantic ridge goes around the souther tip of Africa and then goes up into the Indian ocean and splits around Saudi arabia. The Red sea is expanding from crustal divergence.2/18San Andreas fault: 6 plates and some of the smaller plates might disappear. The big plates move about 2-4 inches per year. Some are moving up to 8 inches a year.Hot spots or radioactively generated pockets of magma under the mantle that include uranium or other radioactive things. They have to steadily give off heat that will melt rather large pockets. They melt all the way up through the mantle and the crust and form a volcano. This is how the Hawaiian islands were formed.Sea mountains: mountains under the water. This hot spot can reform another volcano. Hawaii is in a hot spot. Al-Hajjar and Tibesti in the the top of Africa are formed from the formation of volcanoes a long time ago. This might not be a hot spot anymore. The number and intensity of hotspots have gone down. They have somewhat burned themselves out over time. They come and go over time. At some point in history, there were many hotspots. In the southern pacific, there was A LOT of hot spots. The whole bottom of the sea was kind of lifted up due to the heat underneath the crust. When the crust is lifted up, the water has to be displaced somewhere and it goes onto the other continents. Short wave radiation: energy that is vibrating very quickly that comes from the sun. It extends out into the whole solar system and also hits the earth. It penetrates through the atmosphere very easily (unless there are clouds, they they are reflected back out). The light strikes the earth and heats it up. The surface has more energy in it taken from the sun light. The heat of the surface wants to share the heat with the not as hot surroundings. Re-radiation: effort by the earth to give off the warmth it has taken in by radiation.Some of the energy from the sun gets trapped in the layers of atmosphere. The radiation hits atoms and bounces back and then hits another atom and bounces back again. Carbon dioxide is very good at trapping heat. This explains why there is global warming. The amount of carbon dioxide that is given off has been going up tremendously over time so it is trapping more and more heat in the atmosphere. Methane is also a gas that traps heat. Mountains grow and get rid of carbon dioxide. The movement of tectonic plates reduces the amount of green house gas.2/20Two kinds of volcanoes: 1. Spewer that builds up. Makes a cone volcano. Steep sided. 2. More viscous lava, like smoking water. Makes a shield volcano. Very wide because the lava can travel farther. Steam from volcanos can create a lot of water and then when it comes down the volcano it picks up dirt and what not. Creates a mudslide and kills a lot of people. Mt. Vesuvius, 2000 years ago in Pompeii (Roman period) by what is now Naples, when it erupted, some kind of poisonous gas was spewing from it. It was heavier than air so it would sink and stay towards the ground. Ended up choking people. Also spewed a bunch of ash and when that accumulated, it buried cities and turned into rock. The cities around the volcano that were under the ash were entombed in the hardened ash. Many many years later, the cities wereexcavated to find what was there. On the sides of many volcanos are some very rich soils. That is why so many people die from volcano eruptions. They are farming up the sides of volcanoes and then they blow and they can’t get away fast enough. Geomorphology: study of the changing shapes of the earth. As soon as you lift a rock surface up, it creates more erosion. The higher it is lifted, the more water runs down it. The more that there is erosion, that side of the plate starts to lift up because it is not as heavy asit used to be since it lost all the sediments. Kind of like a see-saw. Endomorphic: changing of shapes from within the earth (creation of volcanoes).Exomorphic: changing of shapes from without