chapter 14: geology and earth resources
DESCRIPTION
Chapter 14: Geology and Earth Resources. 14.1 Earth Processes Shape Our Resources. Earth is a dynamic planet Tectonic processes reshape continents and cause earthquakes and volcanoes. The Solid Earth. Global Earthquakes. Global Volcanoes. The Earth’s Plates. The Plate Tectonics Model. - PowerPoint PPT PresentationTRANSCRIPT
14.1 Earth Processes Shape Our Resources
• Earth is a dynamic planet • Tectonic processes reshape continents and
cause earthquakes and volcanoes
14.2 Rocks And Minerals
• The Rock Cycle Creates And Recycles Rocks • Weathering And Erosion Wear Down Rocks
14.3 Economic Geology And Mineralogy
• Metals are essential to our economy • What Do You Think? Should We Revise Mining
Laws? – The Mining Law of 1872
• Nommetallic minerals include gravel, clay, sand, and salts
14.4 Environmental Effects of Resource Extraction
• Mining can have serious environmental impacts– Acid runoff– Toxic metals
• Processing ores also has negative effects– Sulfur Emissions– Waste Disposal
14.5 Conserving Geological Resources
• Recycling saves energy as well as materials– About 50% of Iron and Steel is Recycled– Recycling Electronics
• New materials can replace mined resources– New Methods of Mining Low-Grade Ores– Synthesizing Minerals (Quartz, Diamonds)– Alternatives (Plastics for Metals)
Three Emerging Resource Problems• Lithium (Batteries)– Evaporites (Bolivia): Far Easier to Extract– Pegmatites (Lepidolite, Spodumene)
• Rare Earths (Electronics)– Col-Tan and Congo Civil War– Chinese Monopoly– California mine to reopen
• Phosphorus (Fertilizer)– Morocco, China, South Africa, Jordan, U.S. = 90%
14.6 Geological Hazards
• Earthquakes can be very destructive– “Earthquakes Don’t Kill People, Buildings Kill
People”• Volcanoes eject gas and ash, as well as lava– Lava is the Least Dangerous Product of Volcanoes
• Landslides are examples of mass wasting
Products of Eruptions
Lava Flows Pyroclastic Debris • Bombs • Lapilli • Ash MudflowsLandslides
Gases • Steam • Carbon Dioxide • H2S
• SO2 • HCl • HF
Environmental Hazards of Volcanoes
Pollution • SO2, HCl in Water Lava Flows Falling Ejecta Ash Falls • Building Collapse • Crop Destruction
Mudflows • Direct Damage (Colombia,
1985) • Floods (Several Types)Blast (Mt. St. Helens, 1980) Pyroclastic Flow (St. Pierre,
1902) Gas (Lake Nyos, Cameroon,
1986)
Volcanic Explosivity IndexVEI Classification Description Plume Ejecta
volume Frequency Example
0 Hawaiian non-explosive < 100 m < 104m³ daily Mauna Loa
1 HawaiianStrombolian gentle 100-1000 m > 104 m³ daily Stromboli
2 StrombolianVulcanian explosive 1-5 km > 106 m³ weekly Galeras 1993
3 Vulcanian /Pelean severe 3-15 km > 107 m³ yearly Lassen 1915
4 Pelean/Plinian cataclysmic 10-25 km > 0.1 km³ ≥ 10 yrs Soufrière Hills 1995
5 Plinian paroxysmal > 25 km > 1 km³ ≥ 50 yrs St. Helens 1980
6 Plinian/Ultra-Plinian colossal > 25 km > 10 km³ ≥ 100 yrs Pinatubo 1991
7 Plinian/Ultra-Plinian super-colossal > 25 km > 100 km³ ≥ 1000 yrs Tambora 1815
8 Ultra-Plinian mega-colossal > 25 km > 1,000 km³ ≥ 10,000 yrs Toba (73,000 BP)
Safest & Most Dangerous Buildings
• Small, Wood-frame House - Safest • Steel-Frame • Reinforced Concrete • Unreinforced Masonry • Adobe - Most Dangerous • Loose Concrete Blocks (Haiti, 2010)