GEOL 108Lg 1st Edition Lecture 12Outline of Last Lecture- What is mass wasting?a. Mass wasting phenomena, causes-Weathering- Efect of Water- Controls on Mass WastingOutline of Current Lecture- Hurricanesa. Mass wasting phenomena, causes- WavesCurrent Lecture-Oceans and water in general are very much capable of storing heat. The redistributon of that energy is what controls climate.-The general wind patterns, general currents in water and atmosphereLarge Scale Climate PhenomenonLost SandHurricanesYou need to be above 26 degrees centgrade to have the conditons to start a hurricane The winds in the higher levels of the atmosphere determine how the hurricane moves They start as a tropical depression, turn into storms, then becomes full scale hurricanes.I n tr o du ct i o nDynamic coastal environment: convergent zone of contnental and oceanic processesVaried topography, climate, and vegetation, more than fifty perfect of the world populaton is concentrated in coastal zonesLong shoreline - roughly 75 percent of U.S. population living in coastal statesLargest cites in coastal zones, coastal hazard problems compounded by increased human activityThe Coastline85% Tourist Industry relies on coastal areas (nation’s largest employer)75% annual U.S. disaster losses are the result of coastal stormsCoastal Hazards-Hurricanes-Tropical Cyclones-Coastal erosion-Tsunamis and tdal currents-Rip currents-Marine floods and inland floodsTake home messages from this lecture: the ocean’s shore is a dynamic balance between the sediment supply and the ocean’s energy - think....would you like to live on the bumper of a car?Earth’s OrbitLow Tides and High TidesTides are created because the Earth and the moon are attracted to each other. The moon pulls at anything on the Earth to bring it closer. The earth’s puller is stronger so everything is held onto except for water. Since the water is always moving, the Earth cannot hold onto it, and the moon is able to pull at it. Each day, there are two high tides and two low tdes. The ocean is constantly moving from high tde to low tde, and then back to high tide.Tides are the periodic rise and falling of large bodies of water. Winds and currents move the surface water causing waves. The gravitatonal attraction of the moon causes the oceans to bulge out in the directon of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Ocean levels fluctuate daily as the sun, moon and earth interact. As the moon travels around the earth and as they, together, travel around the sun, the combined gravitational forces cause the world's oceans to rise and fall. Since the earth is rotatng while this is happening, two tides occureach day.Spring TidesWhen the moon is full or new, the gravitational pull of the moon and sun are together - combined. During this time, the high tides are very high and the lows are low. This is kn o wn as a sp r i n g hi g h t i d e .Spring tides are especially strong tides, they have no relaton to the season of spring.They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon.Spinning of the EarthVelocity = rotation rate x distance from poleThe spinning motion then increases from the pole towards the equatorBeing in a rotatng reference plain leads to the coriolis forceCoriolis ForceDue to the rotation of the earth plus inertiaThere is no REAL force pushing things around - Coriolis Force, is then deemed ficttous (in the sense that there’s no energy expended)Feedback●Warm ocean water leads to evaporation●Warm, moisturized air rises●Condensaton releases latent heat●Low pressure sucks in air, increases evaporaton●Latent heat driven●Die down quickly on land●The weaker the high altitude winds, the stronger the hurricane●Hurricane centers warmer than surroundings●Air in the center of the eye sinks Hurricanesdownward Hurricanes are very expensivenatural disasters. Biggest Hazard Due to HurricanesStorm Surge: mound of water in center of hurricane gettng sucked