1+intro - Fig. Int-E. 02 b Stephen Marshak Blue Mountains,...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Fig. Int-E. 02 b Stephen Marshak Blue Mountains, Eastern Margin, Australia Eroded Upli8ed Highlands Engineering geology and historic monuments Great Wall of China, UNESCO World Heritage site Bet Yuvrin, Israel UNESCO World Heritage site Masada Mountain, Israel, UNESCO World Heritage site Mogou Grotto, Dunhuang, China, UNESCO World Heritage site work with nature... or against nature... Glen Canyon dam, Arizona Dams: earth engineering on a giant scale Like it or Another, more not, if it expensive source of aggregates: isn't grown, Quarrying and it's mined blasting Hydraulic mining for gold Hydraulic fill Man-made natural disaster Road cut, Tennessee Landslides, Panama Canal construction Vaiont Dam, Dolomite Alps, Italy There is a reason we study engioneering geology Study of engineering geology leads to sustainable water supply Sustainable Energy Sources Geothermal tradi@onal hydrothermal systems Natural water source meets near-surface hot rock The Geysers near Santa Rosa Enhanced Geothermal Systems hot dry rock Near surface hot rock but no water Dixie Valley, CA Comparing Operating Fluids for EGS: CO2 vs. Water monitor mass flow, heat extraction rates From conversations with Mark Zoback and Karsten Pruess for the Mayor's Special Panel on Geothermal Energy, City of San Francisco, Wanted: a safe and inexpensive source of heat near San Francisco and the City's properties to the east. Obvious hot spots in near-fault zones but after the seismic event at 5 km below Basel (CH), this is too risky near a major metropolitan area. Solution: shallow (~ 2km) warm sedimentary formations where the coastal range formations meet the Sacramento Valley Heat Flow ~50 (mW/m2) Rock Temp ~150C Heat Flow and Crustal Structure Central California Coast Ranges Very High Heat Flow Continental Crust Great Valley Very Low Heat Flow Oceanic Crust at Depth? @ 2 km, sandstone, 5 ~ 10 m fracture spacing Oh, small heat gradient; can we improve system efficiency? Super Critical Carbon Dioxide! The Idea: Substitute H2O with super critical CO2 as the heat transfer medium. Quantitative assessment of the potential for operating EGS with supercritical CO2 is at an early stage. Studies to date suggest that supercritical CO2 may have significant advantages over water. CO2 circulation fluid is de facto Carbon Sequestration CO2 mass flow of approximately 20 kg/s is required per MW electric power capacity. From experience with long-term circula@on tests with water-based systems, expect a fluid loss rate of order 5%, or 1 kg/s of CO2 per MW electric power. For 1,000 MWe of installed EGS capacity, the amount of fluid lost in circulation and stored underground is estimated as 1 tonne of CO2 per second. This rate of fluid storage is equivalent to CO2 emissions from 3,000 MWe of coal-fired power generation. Science The systema@c analysis of natural phenomenon. Has evolved as the most significant human development for understanding the natural world. Ra@onally explains cosmological evolu@on. Scien@fic understanding can evolve and change. Imaging represen=ng a physical state through means not available to the 5 human senses every moment of our lives we are imaging "The world is too remote from ordinary experience to be merely imagined." - E.O. Wilson All our problems end up being inverse problems How do we reduce "non-uniqueness"? Combine measurements of a variety of physical behaviors Ac=ve and passive seismics km to pm scales Electro-resis=vity and self-poten=al Passive electromagne=cs Seismic tomography Mul=-source inversion and machine learning data integra=on Geology is an Observa@onal Science There is no "absolute" truth we strive for a theory that best matches our knowledge at that @me Theories, "models" of the world, are always being tested and refined as new data, or insight, becomes available An Evolving Image of Earth The ancients thought the Universe was geocentric. Heavenly bodies circle around a mo@onless central Earth. Proven by Ptolemy (100-170 C.E.), the idea was s@ll wrong. Yet it held as doctrine for 1,400 years during the dark ages. It became religious dogma suppor@ng the importance of Earth in the scheme of heaven. A rebirth of ra@onal thinking in 15th- century Europe. Copernicus Published evidence for heliocentricity. Kepler His ellip@cal planetary orbits refuted Ptolemy. Galileo Observed moons orbi@ng Jupiter. The Renaissance These ideas were considered to be heresy. Earth didn't center the Universe. Planetary orbits weren't circular. Not all bodies orbited Earth. The Enlightenment Sir Isaac Newton (1642-1727) devised... The Law of Universal Gravita@on. The Three Laws of Mo@on. The mathema@cs of change (calculus). He proved that natural law governs natural events. Geocentricity faded away. Earth as a Sphere A flat Earth was dispelled by ~ 250 B.C.E. Abundant evidence suggested a spherical Earth. A curved shadow crossed the Moon during eclipses. Only the tops of distant sailing ships were visible. In 1520, Magellan circumnavigated this sphere. infla@on The Modern Universe Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth A8er the Big Bang Condensed nebulae formed flaiened accre@on discs. Heat and mass from collapse ignited nuclear fusion. These 1st-genera@on stars consumed H2 fuel rapidly. As the stars became H2 starved, they ini@ated... Collapse and hea@ng. Heavy element produc@on. Catastrophic explosion (supernova). Nucleosynthesis Stars are truly "element factories." Big bang nucleosynthesis formed lighter elements. Atomic #s 1, 2, 3, 4 and 5 (H, He, Li, Be, and B). Heavier elements are from stellar nucleosynthesis. Atomic #s 6 - 26 (C to Fe). Elements with atomic #s > 26 form during supernovae. Nucleosynthesis When fuel dwindles, stars heat by inward collapse. This leads to a cataclysmic explosion (a supernova). The supernova creates heavier elements. Uranium (atomic # 92) is the heaviest natural element. Subsurface Imaging and Measurement at the Deep Underground Science and Engineering Laboratory Astronomers and astrophysicists can image deep into space to study the forma@on of the universe, the crea@on and death of stars, the collisions between stars, and the dynamics surrounding black holes; yet geologists and engineers have great difficulty imaging and studying processes even tens of meters into the Earth As the Transparent Earth team we will develop an analog to the Hubble telescope into, not away from, the Earth. Transparent Earth wants to make the whole mine and surroundings an observatory NAE Sec@on 11 - Earth Resources Engineering, chaired by Charles Fairhurst. The commiiee is developing a short list of four to six Grand Challenges in Earth Resources Engineering. One Grand Challenge was chosen unanimously, the concept of Transparent Earth Just like physicists using mul@ple frequencies and physical parameters to study the universe, the Transparent Earth project will develop and refine the measurement methodologies and science required to image the Earth at mul@ple scales The Transparent Earth Observatory will combine a number of different physical measurement methodologies to provide complementary informa@on, and strong constraints, for the necessary inversion solu@ons Old Homestake Gold Mine, Lead, South Dakota Gold rush starts in 1875 When closed in 2002, it was the largest and deepest mine in the Western Hemisphere George Hearst made his fortune at Homestake, and generously donated $$$ to UC Berkeley. My lab is in the Hearst Memorial Mining Building 620 m 1500 m 4500 m DUSEL site plans Transparent Earth 2000L Sta@on installa@on and leveling of @ltmeter 2 n-rad calibra@on Transparent Earth 2000L Sta@on Signalto-Noise Spectra DUSEL site plans The Solar System Our solar system also includes... The Sun An average star. Asteroids Rocky or metallic fragments. Comets Fragments of ice orbi@ng the Sun. Kuiper Belt and Oort Belt objects. Solar System Forma@on The Nebular Theory A 3rd, 4th or nth genera@on nebula forms 4.56 Ga. Hydrogen and helium le8 over from the big bang. Heavier elements produced by stellar fusion and supernovae. The nebula condenses into an accre@on disc. Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth Solar System Forma@on Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth The interior heats and becomes soft. Gravity shapes the Earth into a sphere. The interior differentiates into... a nickel-iron core, and a stony (silicate) mantle. Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth Solar System Forma@on Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth Earth: Portrait of a Planet, 3rd edition, by Stephen Marshak Chapter 1: Cosmology and the Birth of Earth ...
View Full Document

This note was uploaded on 02/22/2012 for the course CE 70 taught by Professor Johnson during the Fall '07 term at University of California, Berkeley.

Ask a homework question - tutors are online