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Download 6. Crustal Compression
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WHAT HAPPENS WHEN PIECES OF THE CRUST ARE FORCED TOGETHER ? Extension and injection of mantle material into crust Extension and injection of mantle material into crust Extension and injection of mantle material into crust Crustal Compression Extension and injection of mantle material into crust Extension and injection of mantle material into crust Crustal Compression Extension and injection of mantle material into crust ? Mass leaving Mantle Injected to Crust. Mass leaving Mantle Injected to Crust. Unless Crustal material is returned Consideration of mantle in equal volume the Earth will Conservation of Mass: grow larger and larger, but also “hollower” and “hollower”. CRUSTAL COMPRESSION CRUSTAL COMPRESSION Crustal Thickening CRUSTAL COMPRESSION Crustal Thickening CRUSTAL COMPRESSION Crustal Thickening Crustal Faulting Crustal Convergence and Compression. Heat Denser Crust to Mantle. CRUSTAL ROCKS Two Origins of Crustal Rocks: 1) Continental Crust – Lower density as “floated” to outside of Earth. 2) Oceanic Crust – Higher density as origin deeper in the mantle. Block 2 Block 1 Continental Crust Oceanic Crust Continental Crust CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America 2. Oceanic vs. Oceanic: e.g. Japanese Islands CONVERGENT BOUNDARIES Two types of crustal rocks, thus three possible types of convergence: 1. Oceanic vs. Continental: e.g. Western South America 2. Oceanic vs. Oceanic: e.g. Japanese Islands 3. Continental vs. Continental: e.g. Himalayas 1. GENERAL SETTING WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean MidAtlantic Ridge WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean MidAtlantic Ridge WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America East Pacific Rise Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America East Pacific Rise Pacific Plate Nazca Plate Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America East Pacific Rise Pacific Plate Nazca Plate Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate South America CONVERGENCE AND CRUSTAL COMPRESSION Atlantic Ocean MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Crustal Thickening East Pacific Rise Pacific Plate Nazca Plate MidAtlantic Ridge South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Compressional Faulting East Pacific Rise Pacific Plate Nazca Plate Mato Grosso Brazilian Highlands Guiana Highlands South American Plate MidAtlantic Ridge African Plate WESTERN SOUTH AMERICA Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate South America More dense oceanic crust Sub-ducted beneath South America Mato Grosso Brazilian Highlands Guiana Highlands South American Plate Atlantic Ocean MidAtlantic Ridge African Plate WESTERN SOUTH AMERICA Pacific Ocean Deep ocean trench East Pacific Rise Pacific Plate Nazca Plate South America Mato Grosso Brazilian Highlands Guiana Highlands South American Plate Atlantic Ocean MidAtlantic Ridge African Plate WESTERN SOUTH AMERICA Pacific Ocean Shallow Earthquakes East Pacific Rise South America Deep Earthquakes Mato Grosso Brazilian Highlands Guiana Highlands Atlantic Ocean MidAtlantic Ridge Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean South America Atlantic Ocean Ocean sediments East Pacific Rise Andes Mato Grosso Brazilian Highlands Guiana Highlands MidAtlantic Ridge Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate WESTERN SOUTH AMERICA Pacific Ocean East Pacific Rise South America Andes Active Volcanoes Mato Grosso Brazilian Highlands Guiana Highlands Atlantic Ocean MidAtlantic Ridge Heat and pressure cause melting Pacific Plate Nazca Plate South American Plate African Plate 03.05.b1 03.09.a1 2. JAPANESE ISLANDS GENERAL SETTING JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Eurasian Plate Pacific Plate Nazca Plate Eurasia Moved from North Atlantic Mid-ocean Ridge JAPANESE ISLANDS Asia Sea of Japan Eurasian Plate Pacific Ocean CONVERGENCE AND CRUSTAL COMPRESSION East Pacific Rise Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Eurasian Plate Pacific Ocean The Pacific Plate composed entirely of denser oceanic crust, is subducted beneath the oceanic fringe of the dominantly continental Eurasian Plate. Pacific Plate East Pacific Rise Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Ocean trench Eurasian Plate East Pacific Rise Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean East Pacific Rise Heat and Pressure cause melting Eurasian Plate Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean Shallow and deep earthquakes East Pacific Rise Heat and Pressure cause melting Eurasian Plate Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Eurasian Plate Pacific Ocean Mountain building breaking ocean surface as a series of islands or “island arcs”. Pacific Plate East Pacific Rise Nazca Plate JAPANESE ISLANDS Asia Sea of Compressional faulting Japan permits “recycled” oceanic crust to rise to the surface, producing active volcanoes. Eurasian Plate Pacific Plate Pacific Ocean East Pacific Rise Nazca Plate Island Arcs Ocean Trenches JAPANESE ISLANDS Asia Sea of Japan Pacific Ocean As the Pacific plate is subducted it tends to “rollback” southeastwards, pulling the Japanese Islands further off of Asia. East Pacific Rise “Push” “Pull” Eurasian Plate Pacific Plate Nazca Plate JAPANESE ISLANDS Asia Sea of Japan Eurasian Plate Pacific Ocean Motion of Japanese islands away from Asia causes split of crust and “back arc spreading” beneath the sea of Japan . Pacific Plate East Pacific Rise Nazca Plate 03.00.a1e Source: R.A. Kerr., 2011 Science, 332, p.911 Displacement during Earthquake March 2011. Source: Simons et al., 2011 Science Express CREDIT: ADAPTED FROM THE EARTHQUAKE RESEARCH COMMITTEE, NATIONAL SEISMIC HAZARD MAPS FOR JAPAN (2010), HEADQUARTERS FOR EARTHQUAKE RESEARCH PROMOTION 3. HIMALAYA GENERAL SETTING Eurasia 250 million years ago Indian subcontinent HIMALAYA MOUNTAINS 250 million years ago EARLY DIVERGENCE AND CRUSTAL EXTENSION Africa India Africa and India part of the same continental mass, Gondwanaland, also comprised of present day, South Africa, Australia and Antarctica. HIMALAYA MOUNTAINS 250 million years ago Africa African Plate India Eurasia (Europe and Asia), part of northern continental landmass including present day North America. Eurasia Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Sea of Tethys Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Africa African Plate CONVERGENCE (Ocean vs Continent) AND CRUSTAL COMPRESSION Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Tethys Ocean crust subducted beneath Eurasian continent Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Ocean trench Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Melting under Heat and pressure Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Earthquakes Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Mountain building Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 250 million years ago Volcanoes Africa African Plate Eurasia India Tethys Plate Eurasian Plate HIMALAYA MOUNTAINS 150 million years ago Africa African Plate Indian Ocean India Indo-Australian Plate Sea of Tethys Tethys Plate Eurasia Eurasian Plate HIMALAYA MOUNTAINS 75 million years ago Africa African Plate Indian Ocean India Indo-Australian Plate Sea of Tethys Tethys Plate Eurasia Eurasian Plate HIMALAYA MOUNTAINS Present Himalaya Mountains Indian Ocean Africa India Eurasia Tethys Plate African Plate Indo-Australian Plate Eurasian Plate Wilhan and Gaur, 2013. Buildings as weapons of mass destruction.www.sciencemag.org SCIENCE VOL 341 9, p618-619 HIMALAYA TIBET PLATEAU CHINA PAKISTAN INDIA INDUS BANGLADESH GANGES 03.00.a1d SICHUAN EARTHQUAKE CHINA, 2008. WORLD’S 100 HIGHEST MOUNTAINS 9.0 Himalaya and Associated Ranges ELEVATION (m) 8.5 Andes 8.0 7.5 7.0 6.5 6.0 0 20 60 40 RANK 80 100 VOLCANOES 03.02.b1 WHY NO VOLCANOES? WHAT’S HAPPENING NOW? Present Himalaya Mountains Indian Ocean India Tibetan Plateau Eurasia Tethys Plate Indo-Australian Plate Eurasian Plate WHAT’S HAPPENING NOW? Present Himalaya Mountains Indian Ocean India ? Indo-Australian Plate Tibetan Plateau Eurasia Tethys Plate Eurasian Plate GLOBAL DISTRIBUTION OF EARTHQUAKES GLOBAL DISTRIBUTION OF EARTHQUAKES 1. Western South America GLOBAL DISTRIBUTION OF EARTHQUAKES 2. Japanese Islands GLOBAL DISTRIBUTION OF EARTHQUAKES 3. Himalaya GLOBAL DISTRIBUTION OF VOLCANOES GLOBAL DISTRIBUTION OF VOLCANOES 1. Western South America GLOBAL DISTRIBUTION OF VOLCANOES 2. Japanese Islands GLOBAL DISTRIBUTION OF VOLCANOES 3. Himalaya
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