Activity 11: Understanding Plate Boundaries
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North America Other Continents
Arctic Ocean Europe North Asia America Atlantic Ocean Pacific Ocean Africa Pacific Ocean South Indian America Ocean Oceania Southern Ocean Antarctica LAND & WATER • The surface of the Earth is covered by approximately 71% water and 29% land. • It contains 7 continents and 5 oceans. Land Water EARTH’S HEMISPHERES • The planet Earth can be divided into four different sections or hemispheres. The Equator is an imaginary horizontal line (latitude) that divides the earth into the Northern and Southern hemispheres, while the Prime Meridian is the imaginary vertical line (longitude) that divides the earth into the Eastern and Western hemispheres. • North America, Earth’s 3rd largest continent, includes 23 countries. It contains Bermuda, Canada, Mexico, the United States of America, all Caribbean and Central America countries, as well as Greenland, which is the world’s largest island. North West East LOCATION South • The continent of North America is located in both the Northern and Western hemispheres. It is surrounded by the Arctic Ocean in the north, by the Atlantic Ocean in the east, and by the Pacific Ocean in the west. • It measures 24,256,000 sq. km and takes up a little more than 16% of the land on Earth. North America 16% Other Continents 84% • North America has an approximate population of almost 529 million people, which is about 8% of the World’s total population. 92% 8% North America Other Continents • The Atlantic Ocean is the second largest of Earth’s Oceans. It covers about 15% of the Earth’s total surface area and approximately 21% of its water surface area. -
The Geothermal Activity of the East African Rift
Presented at Short Course IV on Exploration for Geothermal Resources, organized by UNU-GTP, KenGen and GDC, at Lake Naivasha, Kenya, November 1-22, 2009. Kenya Electricity Generating Co., Ltd. GEOTHERMAL TRAINING PROGRAMME Geothermal Development Company THE GEOTHERMAL ACTIVITY OF THE EAST AFRICAN RIFT Peter A. Omenda Geothermal Development Company P. O. Box 100746, Nairobi 00101 KENYA [email protected] ABSTRACT The East Africa Rift System is a classical continental rift system associated with the world-wide mid ocean rift systems. The rift extends from the Red Sea – Afar triple junction through Ethiopian highlands, Kenya, Tanzania and Malawi to Mozambique in the south. The western branch passes through Uganda, DRC and Rwanda while the nascent south-western branch runs through Luangwa and Kariba rifts in Zambia into Botswana. The volcanic and tectonic activity in the rift started about 30 million years ago and in the eastern branch the activity involved faulting and eruption of large volumes of mafic and silicic lavas and pyroclastics. The western branch, typified by paucity of volcanism, is younger and dominated by faulting that has created deep basins currently filled with lakes and sediments. Geothermal activity in the rift is manifested by the occurrences of Quaternary volcanoes, hotsprings, fumaroles, boiling pools, hot and steaming grounds, geysers and sulphur deposits. The manifestations are abundant and stronger in the eastern branch that encompasses Afar, Ethiopian and Kenya rifts while in the western branch, the activity is subdued and occurs largely as hotsprings and fumaroles. Detailed and reconnaissance studies of geothermal potential in Eastern Africa indicates that the region has potential of 2,500MWe to 6,500MWe. -
The East African Rift System in the Light of KRISP 90
ELSEVIER Tectonophysics 236 (1994) 465-483 The East African rift system in the light of KRISP 90 G.R. Keller a, C. Prodehl b, J. Mechie b,l, K. Fuchs b, M.A. Khan ‘, P.K.H. Maguire ‘, W.D. Mooney d, U. Achauer e, P.M. Davis f, R.P. Meyer g, L.W. Braile h, 1.0. Nyambok i, G.A. Thompson J a Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968-0555, USA b Geophysikalisches Institut, Universitdt Karlwuhe, Hertzstrasse 16, D-76187Karlsruhe, Germany ’ Department of Geology, University of Leicester, University Road, Leicester LEl 7RH, UK d U.S. Geological Survey, Office of Earthquake Research, 345 Middlefield Road, Menlo Park, CA 94025, USA ’ Institut de Physique du Globe, Universite’ de Strasbourg, 5 Rue Ret& Descartes, F-67084 Strasbourg, France ‘Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90024, USA ’ Department of Geology and Geophysics, University of Wuconsin at Madison, Madison, WI 53706, USA h Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN 47907, USA i Department of Geology, University of Nairobi, P.O. Box 14576, Nairobi, Kenya ’ Department of Geophysics, Stanford University, Stanford, CA 94305, USA Received 21 September 1992; accepted 8 November 1993 Abstract On the basis of a test experiment in 1985 (KRISP 85) an integrated seismic-refraction/ teleseismic survey (KRISP 90) was undertaken to study the deep structure beneath the Kenya rift down to depths of NO-150 km. This paper summarizes the highlights of KRISP 90 as reported in this volume and discusses their broad implications as well as the structure of the Kenya rift in the general framework of other continental rifts. -
Geography Notes.Pdf
THE GLOBE What is a globe? a small model of the Earth Parts of a globe: equator - the line on the globe halfway between the North Pole and the South Pole poles - the northern-most and southern-most points on the Earth 1. North Pole 2. South Pole hemispheres - half of the earth, divided by the equator (North & South) and the prime meridian (East and West) 1. Northern Hemisphere 2. Southern Hemisphere 3. Eastern Hemisphere 4. Western Hemisphere continents - the largest land areas on Earth 1. North America 2. South America 3. Europe 4. Asia 5. Africa 6. Australia 7. Antarctica oceans - the largest water areas on Earth 1. Atlantic Ocean 2. Pacific Ocean 3. Indian Ocean 4. Arctic Ocean 5. Antarctic Ocean WORLD MAP ** NOTE: Our textbooks call the “Southern Ocean” the “Antarctic Ocean” ** North America The three major countries of North America are: 1. Canada 2. United States 3. Mexico Where Do We Live? We live in the Western & Northern Hemispheres. We live on the continent of North America. The other 2 large countries on this continent are Canada and Mexico. The name of our country is the United States. There are 50 states in it, but when it first became a country, there were only 13 states. The name of our state is New York. Its capital city is Albany. GEOGRAPHY STUDY GUIDE You will need to know: VOCABULARY: equator globe hemisphere continent ocean compass WORLD MAP - be able to label 7 continents and 5 oceans 3 Large Countries of North America 1. United States 2. Canada 3. -
Africa-Arabia-Eurasia Plate Interactions and Implications for the Dynamics of Mediterranean Subduction and Red Sea Rifting
This page added by the GeoPRISMS office. Africa-Arabia-Eurasia plate interactions and implications for the dynamics of Mediterranean subduction and Red Sea rifting Authors: R. Reilinger, B. Hager, L. Royden, C. Burchfiel, R. Van der Hilst Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA USA, [email protected], Tel: (617)253 -7860 This page added by the GeoPRISMS office. Our proposed GeoPRISMS Initiative is based on the premise that understanding the mechanics of plate motions (i.e., the force balance on the plates) is necessary to develop realistic models for plate interactions, including processes at subduction and extensional (rifting) plate boundaries. Important advances are being made with new geologic and geophysical techniques and observations that are providing fundamental insights into the dynamics of these plate tectonic processes. Our proposed research addresses directly the following questions identified in the GeoPRISMS SCD Draft Science Plan: 4.2 (How does deformation across the subduction plate boundary evolve in space and time, through the seismic cycle and beyond?), 4.6 (What are the physical and chemical conditions that control subduction zone initiation and the development of mature arc systems?), and 4.7 (What are the critical feedbacks between surface processes and subduction zone mechanics and dynamics?). It has long been recognized that the Greater Mediterranean region provides a natural laboratory to study a wide range of geodynamic processes (Figure 1) including ocean subduction and continent- continent collision (Hellenic arc, Arabia-Eurasia collision), lithospheric delamination (E Turkey High Plateau, Alboran Sea/High Atlas), back-arc extension (Mediterranean basins, including Alboran, Central Mediterranean, Aegean), “escape” tectonics and associated continental transform faulting (Anatolia, North and East Anatolian faults), and active continental and ocean rifting (East African and northern Red Sea rifting, central Red Sea and Gulf of Aden young ocean rifting). -
Atlas of Rare Endemic Vascular Plants of the Arctic
Atlas of Rare Endemic Vascular Plants of the Arctic Technical Report No. 3 About CAFF Theprogram for the Conservation of Arctic Flora and Fauna (CAFF) of the Arctic Council was established lo address the special needs of Arctic ecosystems, species and thcir habitats in the rapid ly developing Arctic region. Itwas initiated as one of'four programs of the Arctic Environmental Protcction Strategy (AEPS) which was adopted by Canada, Denmark/Greenland, Finland, lceland, Norway, Russia, Swcdcn and the United States through a Ministeria! Declaration at Rovaniemi, Finland in 1991. Other programs initi ated under the AEPS and overlaken hy the Are.tie Council are the ArcticMonitoring and assessment Programme (AMAP), the program for Emergency Prevention, Preparcd ness and Response (EPPR) and the program for Protection of the Arctic Marine Envi ronment (PAME). Sinceits inaugural mccti.ng in Ottawa, Canada in 1992, the CAFF program has provided scientists, conscrvation managers and groups, and indigenous people of the north with a distinct forum in which lo tackle a wide range of Arctic conservation issues at the cir cumpolar level. CAFF's main goals, which are achieved in keeping with the concepts of sustainable developrnertt and utilisation, are: • to conserve Arctic Jlora and fauna, thcir diversity and thcir habitats; • to protect the Arctic ecosystems from threats; • to improve conservation management laws, reg ulations and practices for the Arclic; • to integrale Arctic interests into global conservation fora. CAFF operates rhrough a system of Designated Agencies and National Representatives responsible for CAFF in thcir rcspcctivc countries. CAFF also has an International Work ing Group wh.ith has met annually to assess progrcss and to develop Annual WorkPlans. -
The Science Behind Volcanoes
The Science Behind Volcanoes A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from the magma chamber below the surface. Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so- called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. Volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere. -
Atlantos D9.5. European Strategy for All Atlantic Ocean Observing System
European Strategy for All-Atlantic Ocean Observing System This report is a European contribution to the implementation of the All-Atlantic Ocean Observing System (AtlantOS). This report presents a forward look at the European capability in the Atlantic ocean observing and proposes goals and actions to be achieved by 2025 and 2030. Editors: Erik Buch, Sandra Ketelhake, Kate Larkin and Michael Ott Contributors: Michele Barbier, Angelika Brandt, Peter Brandt, Brad DeYoung, Dina Eparkhina, Vicente Fernandez, Rafael González-Quirós, Jose Joaquin Hernandez Brito, Pierre-Yves Le Traon, Glenn Nolan, Artur Palacz, Nadia Pinardi, Sylvie Pouliquen, Isabel Sousa Pinto, Toste Tanhua, Victor Turpin, Martin Visbeck, Anne-Cathrin Wölfl Design coordination: Dina Eparkhina The AtlantOS project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 633211. This out- put reflects the views only of the authors, and the European Union cannot be held responsible for any use which may be made of this information contained therein. 2 3 Contents Executive Summary 4 1. European strategy for the All-Atlantic Ocean Observing System (AtlantOS) 6 1.1 Why do we need a European strategy for Atlantic ocean observing? 7 1.2 Structure of this strategy 8 2. Meeting user needs: from requirement setting to product delivery 9 2.1 Recurring process of multi-stakeholder consultation for user requirements and co-design 9 2.2 The ‘blue’ value chain – products driven by user needs 10 2.3 European policy drivers 12 3. Existing and evolving observing networks and systems 13 3.1 Present capabilities and future targets 13 3.2 Role of observing networks and observing systems in the blue value chain 15 3.3 Advancing the observing system through new technology 17 4. -
Himalaya - Southern-Tibet: the Typical Continent-Continent Collision Orogen
237 Himalaya - Southern-Tibet: the typical continent-continent collision orogen When an oceanic plate is subducted beneath a continental lithosphere, an Andean mountain range develops on the edge of the continent. If the subducting plate also contains some continental lithosphere, plate convergence eventually brings both continents into juxtaposition. While the oceanic lithosphere is relatively dense and sinks into the asthenosphere, the greater sialic content of the continental lithosphere ascribes positive buoyancy in the asthenosphere, which hinders the continental lithosphere to be subducted any great distance. Consequently, a continental lithosphere arriving at a trench will confront the overriding continent. Rapid relative convergence is halted and crustal shortening forms a collision mountain range. The plane marking the locus of collision is a suture, which usually preserves slivers of the oceanic lithosphere that formerly separated the continents, known as ophiolites. The collision between the Indian subcontinent and what is now Tibet began in the Eocene. It involved and still involves north-south convergence throughout southern Tibet and the Himalayas. This youthful mountain area is the type example for studies of continental collision processes. The Himalayas Location The Himalayas form a nearly 3000 km long, 250-350 km wide range between India to the south and the huge Tibetan plateau, with a mean elevation of 5000 m, to the north. The Himalayan mountain belt has a relatively simple, arcuate, and cylindrical geometry over most of its length and terminates at both ends in nearly transverse syntaxes, i.e. areas where orogenic structures turn sharply about a vertical axis. Both syntaxes are named after the main peaks that tower above them, the Namche Barwa (7756 m) to the east and the Nanga Parbat (8138 m) to the west, in Pakistan. -
6.5 Climate Change Projections in the Upper Danube (European Alps) and the Upper Brahmaputra (Himalayas)
6.5 CLIMATE CHANGE PROJECTIONS IN THE UPPER DANUBE (EUROPEAN ALPS) AND THE UPPER BRAHMAPUTRA (HIMALAYAS) Bodo Ahrens∗ and Andreas Dobler IAU, Goethe-University, Frankfurt am Main, Germany 1 INTRODUCTION tion (for further details see Dobler and Ahrens, 2008). In the following sections, statistically Coarse-grid global circulation models (GCMs) downscaled ECHAM5 precipitation fields are do not allow for regional estimates of water bal- named ECHAM5-Γ. They have a grid resolution ◦ ance or trends of extreme precipitation. This is of 0.5 . especially true in complex terrain. Therefore, Trends of daily precipitation statistics are cal- downscaling of the global simulations to gen- culated for all four seasons of the years during erate regional precipitation is necessary. This the simulation period 1960-2080. An overview paper discusses dynamical and statistical down- on the precipitation statistics is provided in Ta- scaling in two major river basins (RBs): (1) the ble 1. The wet day threshold is set to be 1 upper Danube river basin (UDRB) covering an mm/d. Beside the two major RBs, 5 sub-areas area of 76’653 km2 in the European Alps and (2) of interest (see Figs. 1 and 2) are considered. the upper Brahmaputra river basin (UBRB) with The sizes of the single areas (in number of grid ◦ about 500’000 km2 in the Himalayas. The dis- points on the 0.44 simulation grids) are: UDRB cussion focuses on simulated changes of daily 51, Lech RB 5, Salzach RB 7, UBRB 275, As- precipitation statistics in the two RBs. sam 47, Lhasa RB 22 and Wang-Chu RB 8. -
Himalayan Glaciers
Himalayan Glaciers Climate Change, Water Resources, and Water Security Scientific evidence shows that most glaciers in South Asia’s Hindu Kush Himalayan region are retreating, but the consequences for the region’s water supply are unclear, this report finds. The Hindu Kush Himalayan region is the location of several of Asia’s great river systems, which provide water for drinking, irrigation, and other uses for about 1.5 billion people. Recent studies show that at lower elevations, glacial retreat is unlikely to cause significant changes in water availability over the next several decades, but other factors, including groundwater depletion and increasing human water use, could have a greater impact. Higher elevation areas could experience altered water flow in some river basins if current rates of glacial retreat continue, but shifts in the location, intensity, and variability of rain and snow due to climate change will likely have a greater impact on regional water supplies. he Himalayan region, which Tcovers eight countries across Asia, is home to some of the world’s largest and most spectacular glaciers. The melt- water generated from these glaciers each summer supplements the rivers and streams of the region, including several of Asia’s great river systems such as the Indus, Ganges, and Brahmaputra. Rising tempera- tures due to climate change are causing glaciers worldwide to Figure 1. Extending over 2000 kilometers across the Asian continent and including all shrink in volume and or part of Afghanistan, Bangladesh, Bhutan, China, India, Nepal, and Pakistan, the mass, a phenomenon Hindu Kush Himalayan region is the source for many of Asia’s major river systems, known as glacial including the Indus, Ganges, and Brahmaputra. -
Historical Background: Early Exploration in the East African Rift--The Gregory Rift Valley
Downloaded from http://sp.lyellcollection.org/ by guest on September 26, 2021 SIR PETER KENT Historical background: Early exploration in the East African Rift--The Gregory Rift Valley In relation to modern lines of communication it seems surprising that the Gregory Rift Valley was the last part of the system to become known. Much of the earlier exploration had however been centred on the problem of the sources of the Nile, and in consequence the Western or Albertine Rift was explored by Samuel Baker as early as 1862/63 (Baker 1866). Additionally there was a strong tendency to use the convenient base at Zanzibar Island for journeys inland by the Arab slave trading routes from Pangani and Bagamoyo; these led to the Tanganyika Rift and Nyasaland rather than to the area of modern Kenya. The first penetrations into the Gregory Rift area were in I883; Joseph Thomson made an extensive journey into Central Kenya which he described in his book of 1887, 'Through Masai Land' which had as a subtitle, 'a journey of exploration among the snowclad volcanic mountains and strange tribes of Eastern Equatorial Africa--being the narrative of the Royal Geographical Society's Expedition to Mount Kenya and Lake Victoria Nyanza i883-84'. In his classic journey Thomson practically encircled the lower slopes of Mount Kilimanjaro and reached the Gregory Rift wall near the Ngong Hills. He then went north to Lake Baringo and westwards to Lake Victoria, before returning to his starting point at Mombasa. His observations on the geology were of good standard for the time.