GEOL 1425 1ST Edition Lecture 16 Outline of Last Lecture I. Volcanoes as geosystemsII. Lava and other volcanic depositsOutline of Current Lecture I. Geosystem interactionsII. Volcanism and human affairsIII. ReviewCurrent Lecture—Volcanoes 2I. Geosystem interactionsa. Extinct volcano in Africa thought to be dormant, but many people in area were injured from the harsh gasses it was still submitting. b. Geyser—hot-water fountain that emits water at very high forcesc. Volcanism and the atmosphere—Pinatubo Explosion, very violent and much particles and ash erupted into atmosphered. Almost all volcanism can be explained by activity of plates, and occur on boundaries where plates converge (80%), separate (15%), and within plate interiors (5%). e. Mantle plumes—ex in Hawaiian island chain. Over time the plates have moved and formed from the volcanic activity, slowly moving away from the volcanic plume. Plate movement takes older volcanoes farther from the plume, while themore active ones stay closer. Currently the plume is under Hawaii. Hawaii is mostactive hot spot on earth todayThese 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.f. Large igneous provinces (LIPs)—100s of km thick, on land or on oceans, lava eruptions can be as large as the entire mid-ocean ridge system. Much more lava involved than normal hot spots; here a “plume head” leads the way. If the head is large enough, fissure eruptions are possibleII. Volcanism and human affairsa. Hazards: lahars (muddy river), flank collapse (could potentially produce a tsunami), caldera collapse, eruption cloudsb. Mantle-plume hypothesis—predicting of eruptions is difficult, there are often seismic clues but not always. There is no way to control eruptions, one could try to divert lava flow heading toward a settlement but not control the eruption. c. Natural resources—volcanic soils are often very mineral-rich. We can use volcanic products for various materials like building roads. Ore formation- precious metals and rare earth metals in demand for high technologies. Heat energy is a somewhat renewable resource from geothermal energy, unlike fossil fuels which are extracted and then done. d. Many fatalities associated with eruptions. e. Geothermal energy—very useful and a good side of volcanic activityIII. Concepts and keywords:a. Andesiteb. Basaltic magmac. Gas content of lavad. Rhyolitee. Dioritef. Volcanic domesg. Lava viscosityh. Vesiclesi. Volcano forms and examplesj. Volcano collapsek. Lithified pyroclastic depositsl. Leharsm. Fumerolesn. Diatremeso. Pyroclastic flowp. Fissure eruptionsq. Location of most active volcanoesr. Flood basaltss. Age of the basaltic sea floort. Emperor seamountsu. Distribution of large igneous provincesv. Types of volcanic