Presentation on theme: "Volcanoes Tungerahua Volcano, Ecuador Picture by Alcinoe Calahorrano"— Presentation transcript:
1 Volcanoes Tungerahua Volcano, Ecuador Picture by Alcinoe Calahorrano Talk about this volcano when it erupted and what it is doing right now.Tungerahua Volcano, EcuadorPicture by Alcinoe CalahorranoVolcanoes
2 Volcanoes form around vents that release magma onto the Earth’s surface. LavaMagma chamber
3 Nonexplosive Eruptions Volcanic EruptionsLava flowLava fountainNonexplosive EruptionsExplosive EruptionsWhat is Lava?-magma that flows onto the Earth’s surface
4 The Composition of Magma Determines whether it is explosive or not! waterHigh water contentMore likely to be !!!High contentMore likely to be !!!Why?Silica has a thick, stiff consistencyFlows slowlyTends to Harden in the volcano’s ventEXPLOSIVEsilicaEXPLOSIVEThe Earth is made of many different and distinct layers. The deeper layers are composed of heavier materials; they are hotter, denser and under much greater pressure than the outer layers. Core: The Earth has a iron-nickel core that is about 2,100 miles in radius. The inner core may have a temperature up to about 13,000°F (7,200°C = 7,500 K), which is hotter than the surface of the Sun. The inner core (which has a radius of about 750 miles (1,228 km) is solid. The outer core is in a liquid state and is about 1,400 miles (2,260 km) thick.
5 What Erupts from a Volcano? Blocky lavaLava can bethick or thin.PahoehoeAaPillow lava
6 What Erupts from a Volcano? Pyroclastic materialRock fragments created by eruptionsmagma explodes from volcano and solidifies in the airexisting rock is shattered by powerful eruptionsEXPLOSIVELapilliVolcanic bombsVolcanic blocksVolcanic ash
7 How do volcanoes affect the Earth? Flows and Falloutshot ash can flow really quicklyKnock down buildingsDam rivers (flooding/drought)Kill crops and livestockClimatic ChangesAsh & Gases can block sunlightDrop average global temperature noticeably
9 Craters, Calderas, and Lava Plateau From explosions of material out of the vent and the collapse of material back into ventCalderaMuch larger depression that forms when magma chamber empties and its roof collapsesLava PlateauForms when lava erupts from long cracks, or fissures, and spreads out evenly (thousands of km)
10 What causes volcanoes? The Formation of Magma Mantle rock melts when the temperature increasesor the pressure decreases.There are lots of uncertainties about why volcanoes form, because scientists have to rely on models based on rock samples and other data.
11 What causes volcanoes? Where Volcanoes Form Tectonic Plate Boundaries!!!There are lots of uncertainties about why volcanoes form, because scientists have to rely on models based on rock samples and other data.~75% world’s active volcanoes in Ring of Fire
14 How do volcanologists predict eruptions? Measuring Small QuakesBefore eruption, increase in number & intensityMeasuring SlopeBulges may form with magma (tiltmeter)Measuring Volcanic GasesOutflow of volcanic gasesSulfur dioxide, carbon dioxideMeasuring Temperature from OrbitMeasure changes in temperature over time
15 You should not be a Volcanologist if…. You don’t like hiking, backbacking, rockclimbing, etc.You are not interested in experiencing extreme temperatures and heights.If you don’t like to travel to incredible places and see breathtaking views of the world.Robert McGimseyUSGSA. Ozerov