GEOG 101 1st Edition Lecture 18Outline of Last Lecture I. The Tectonic Cyclei. Key TermsOutline of Current LectureI. Natural Hazardsi. Earthquakesii. TsunamisII. The Rock Cyclei. Igneous ii. Sedimentary iii. MetamorphicLectureI. Natural Hazards - Natural Hazards exist in broadly predictable locations.- Natural Disasters can occur when humans interact directly with natural hazards.i. Earthquakes-Earthquake hazards are greatest along plate boundaries. The greatest amount of activity is in southern Asia. Some locations face high risk of secondary effects of earthquakes, such as tsunamis. ii. Tsunamis-Tsunamis form usually as a result of changes in ocean-floor topography. The sizeof a tsunami depends upon the amount and location of seafloor displacement, and seafloor topography. Tsunamis are rapid, ocean-wide waves and people onlyhave limited warning systems. Some societies have more resources than others to assess and respond to risk.iii. Volcanoes- There are different types of volcanoes that pose different hazards to people.Felsic- explosive lavaThese 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.Mafic- effusive lavaII. The Rock Cycle-The Rock Cycle is continuous transition through geological time among three rock types. The rock cycle connects to the tectonic cycle and the water cycle. -Different types of rock produce distinct landforms.-Different phases of the rock cycle occur in different locations along the surface and subsurface. i. Igneous -Igneous Rock: 3 types; lava, granite, basalt. The rate at which igneous rock cools determines crystal size.-Intrusive igneous rock is called crystalline because it is formed of crystallized minerals.-Extrusive igneous rock is non-crystalline, or very small crystals.ii. Sedimentary -Sedimentary Rock: 3 types; limestone, sandstone, shale. Fossil fuels are types of sedimentary rock, made of dead plants and animals. Sedimentary rocks can form from any type of deposit, but most form from seafloor deposits.iii. Metamorphic-Metamorphic Rock: 3 types; marble, slate, gneiss. Forms along the edge of igneous rock; called contact