EOSC 114 Notes for Exam - Volcanoes

3 Pages
380 Views
Unlock Document

Department
Earth and Ocean Sciences
Course
EOSC 114
Professor
Leah May Ver
Semester
Fall

Description
EOSC 114: Volcanoes Learning Goals 1. Explain what magma density and magma Density: less mass/volume so magma (melted viscosity are. rock) rises above solid rock. Viscosity: how runny, fluid magma is; low viscosity (runny, flowing) will rise through crust; dependant on SiO c2ntent and temperature more SiO , higher viscosity 2 (stronger bond = more solid) - For magma to rise through crust, it must have lower density than crust, low viscosity, and hot enough to stay liquid 2. List the different categories of volcanic - Intrusive rocksmagma that cools slowly rocks and explain the differences between the underground, crystals visible magmas they came from. - Extrusive rocks  magma cools quickly on surface, crystals too small to see -Mafic magma: low SiO co2tent, low viscosity, less explosive (ex. form basalt rocks) -Felsic magma: high SiO content, high 2 viscosity, more explosive (ex. form rhyolite rocks) BasaltAndesiteRhyolite 3. Explain why some magmas erupt Depends on gas content and viscosity explosively (as pyroclastic material) and some Lava: low gas content, low viscosity, flows as magmas erupt effusively (as lava). pahoehoe or a’a (see 4) Volcanic glass: magma cools quickly before crystallizationobsidian if solid or pumice if bubbles Pyroclastic material: high gas content, high viscosity more explosive 4. Explain the differences between pahoehoe Pahoehoe: smooth, rope-like texture and a'a lavas A’a: rough, painful surface 5. Describe the different types of volcanic eruptions and how they are related to magma properties. 6. Describe the morphology, dominant rock Mafic volcanoes: type and typical eruption style of the different -Shield volcano flat, broad (100s of km wide) types of volcanoes. basalt lava flows; low explosivity -Scoria/Cinder conessmall, volcanic vent made of pyroclastic material, found around other volcanoes (ie. shield) or on own; medium-high volatility Intermediate to Felsic volcanoes: -Composite/Stratovolcanoesconical shape with steep slope, made of layers of lava and pyroclastic material; medium-high volatility (bigger than cinder cones so more dangerous) -Lava domelava flow collection over vent, keeps expanding with explosions; medium volatility when erupts EOSC 114: Volcanoes Learning Goals Felsic volcanoes: - Calderasdepressions in crust formed when explosion causes collapse Don’t confuse with crater, which is just a depression when eruption occurs without collapse 7. Explain what lava flows, fire fountains, lava -Lava flow: melted magma rises through crust bombs, and volcanic ash are and how they and flows out of volcano slowly form. -Fire fountain: basaltic lava with lots of gas erupts (small) and as it falls, cools as lava -Lava bombs: large chunks of pyroclastic material -Volcanic ash 8. Describe the particular hazards associated -Lava flow: destroy infrastructure with lava flows, fire fountaining, lava bombs, -Fire fountain: very hot and ash fall. -Lava bomb:can kill people, damage things -Ash fall:can suffocate people, bury cities, stop planes/car engines, block solar
More Less

Related notes for EOSC 114

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit