Transcript Earth
01_Part_Opener.jpg Geology 107 - Physical Geology Fall 2006 Schedule: Lecture: MWF 11 AM, Room 112, Chem Annex Laboratory: Mon or Tues, Room 259 Natural History Bldg (Mon labs today!) Text: Marshak, S. (2004) Earth: Portrait of a Planet 2nd Edition + lab manual Instructor Information: Craig Lundstrom Office: 255 Natural History Building Phone: 244-6293 E-mail: [email protected] Office hours: M, W noon-1:30 pm, by appt. Laboratory Instructors Eileen Herrstrom, 106 NHB, [email protected], 333-7732 David Robison, 208 NHB, [email protected], 244-6048 Melissa Farmer, 265 Morrill. [email protected], 244-9871 field trip to Southeast Missouri on the weekend of October 13-15. This trip is required for geology majors and encouraged for others-- Grading: Lecture Exams (54%) - There will be two one-hour lecture exams (13% each) given during regular class hours and one cumulative final exam (28%) during exam week. EXAM I - Friday, Sept 29 --> Chapters 1-8 EXAM II - Friday, November 3--> Chapters 9-13 Final EXAM - Monday, December 11, 8-11 AM --> cumulative but will slightly emphasize the material covered after EXAM II Laboratory exercises and exams (40%) Field trip notes or web based assignment (4%) Take home problems (2%) Why study geology? Resources Hazards Environment/Climate Basic knowledge about formation of the Earth, other planets How the Earth works Origin of life 01_00.jpg Why am I interested?1. Issue of scale-both time and space 2. Still major questions to be answered“Why does the Earth have continental crust?” (the reason for complex life!) we are still experiencing the revolution of plate tectonics today General course content I. Plate Tectonic context II. Earth Materials/properties-formation III. Interior processes/hazards/deep time IV. Earths surface/hazards/human impact V. Resources and Global Change A Brief Intro to Plate Tectonics… Plate: a rigid, uppermost section of the solid Earth ~10 major plates moving slowly (~cm/yr rates) -interaction along edges controls much of the tectonic/volcanic activity on Earth. Exception is hot spot track like Hawaii Types of Plate Boundaries: 1. Convergent margins- plates move toward each other: subduction zones, continental collisions 2. Divergent margins- plates move away from each other: mid-ocean ridges, rift zones 3. Transform boundaries- plates slide past each other: strike slip fault, oceanic transforms The Universe Geocentric view did not disappear until late 1500s Observe that spectra of distant galaxies/stars are all red shifted (doppler effect) means that everything is moving away from us--so entire universe is expanding. Leads to the Big Bang hypothesis that expansion began at specific time from a giant explosion--13.6 Ga Since then, things have been clumping together The Solar system Formation from the solar nebula-rotating disk of gas and dust around proto-sun Planetessimals form and these clumps combine to eventually form planets 4 inner planets -”terrestrial;” small and rocky 4 outer planets-” jovian;” gas and ice Pluto no longer a planet!!! Our moon probably formed by collision with a mars-sized protoplanet (early-oldest moon rocks 4.44Ga while Earth/meteorite age is 4.56) Solar System Formation This animation shows the collapse of a rotating dust cloud to form a solar system with a central star and orbiting planets. The angular velocity vector is yellow. Escape of light elements to the outer regions occurs immediately after the collapse phase. PC version Mac version 01_10.jpg Comparison of the rocky planets Similar bulk materials-but very different in process Mercury-too hot Venus-also hot (green house) Earth-PT, Cont Crust Mars (cold-no greenhouse) 01_13and15.jpg Sun pumps out, atoms, radiation (solar wind) Earth has magnetic field that deflects much the solar wind 01_17a.jpg 01_17b.jpg Earth rotates on axis causing day and night How do we know? Earth’s circumference calculated in 200 BC! Within 2% of true value!! 24,865 miles 40,008 km