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Geology of Hawaii Reefs
11 Geology of Hawaii Reefs Charles H. Fletcher, Chris Bochicchio, Chris L. Conger, Mary S. Engels, Eden J. Feirstein, Neil Frazer, Craig R. Glenn, Richard W. Grigg, Eric E. Grossman, Jodi N. Harney, Ebitari Isoun, Colin V. Murray-Wallace, John J. Rooney, Ken H. Rubin, Clark E. Sherman, and Sean Vitousek 11.1 Geologic Framework The eight main islands in the state: Hawaii, Maui, Kahoolawe , Lanai , Molokai , Oahu , Kauai , of the Hawaii Islands and Niihau , make up 99% of the land area of the Hawaii Archipelago. The remainder comprises 11.1.1 Introduction 124 small volcanic and carbonate islets offshore The Hawaii hot spot lies in the mantle under, or of the main islands, and to the northwest. Each just to the south of, the Big Island of Hawaii. Two main island is the top of one or more massive active subaerial volcanoes and one active submarine shield volcanoes (named after their long low pro- volcano reveal its productivity. Centrally located on file like a warriors shield) extending thousands of the Pacific Plate, the hot spot is the source of the meters to the seafloor below. Mauna Kea , on the Hawaii Island Archipelago and its northern arm, the island of Hawaii, stands 4,200 m above sea level Emperor Seamount Chain (Fig. 11.1). and 9,450 m from seafloor to summit, taller than This system of high volcanic islands and asso- any other mountain on Earth from base to peak. ciated reefs, banks, atolls, sandy shoals, and Mauna Loa , the “long” mountain, is the most seamounts spans over 30° of latitude across the massive single topographic feature on the planet. -
Appendix D Soil Series Descriptions
Appendix D Soil Series Descriptions Soil Series Descriptions Soil Orders Mollisols — This order covers a considerable land area of western and southern Minnesota and is the basis for the state's productive agricultural base. The formative syllable, oll, is derived from the Latin word mollis, or soft. Its most distinguishing feature is a thick, dark-colored surface layer that is high in nutrients. It occurs throughout the former prairie areas of Minnesota. The Latin term for soft in its name is descriptive in that most of these soils usually have a rather loose, low-density surface. Three suborders of mollisols occur in Minnesota: Aquolls, Udolls, and Ustolls. Alfisols — This order covers a large land area in Minnesota, part of which is now cultivated and part forested. Alf is the formative element and is coined from a soil term, pedalfer. Pedalfers were identified in the 1930s as soils of the eastern part of the United States with an accumulation of aluminum and iron. The alf refers to the chemical symbols for aluminum (Al) and iron (Fe). Alfisols are primarily fertile soils of the forest, formed in loamy or clayey material. The surface layer of soil, usually light gray or brown, has less clay in it than does the subsoil. These soils are usually moist during the summer, although they may dry during occasional droughts. Two suborders of alfisols occur in Minnesota: Aqualfs and Udalfs. Histosols — The formative element in the name is ist and comes from the Greek word histos, which means tissue. This is an appropriate association because these soils are formed from plant remains in wet environments like marshes and bogs. -
25. PELAGIC Sedimentsi
^ 25. PELAGIC SEDIMENTSi G. Arrhenius 1. Concept of Pelagic Sedimentation The term pelagic sediment is often rather loosely defined. It is generally applied to marine sediments in which the fraction derived from the continents indicates deposition from a dilute mineral suspension distributed throughout deep-ocean water. It appears logical to base a precise definition of pelagic sediments on some limiting property of this suspension, such as concentration or rate of removal. Further, the property chosen should, if possible, be reflected in the ensuing deposit, so that the criterion in question can be applied to ancient sediments. Extensive measurements of the concentration of particulate matter in sea- water have been carried out by Jerlov (1953); however, these measurements reflect the sum of both the terrigenous mineral sol and particles of organic (biotic) origin. Aluminosilicates form a major part of the inorganic mineral suspension; aluminum is useful as an indicator of these, since this element forms 7 to 9% of the total inorganic component, 2 and can be quantitatively determined at concentration levels down to 3 x lO^i^ (Sackett and Arrhenius, 1962). Measurements of the amount of particulate aluminum in North Pacific deep water indicate an average concentration of 23 [xg/1. of mineral suspensoid, or 10 mg in a vertical sea-water column with a 1 cm^ cross-section at oceanic depth. The mass of mineral particles larger than 0.5 [x constitutes 60%, or less, of the total. From the concentration of the suspensoid and the rate of fallout of terrigenous minerals on the ocean floor, an average passage time (Barth, 1952) of less than 100 years is obtained for the fraction of particles larger than 0.5 [i. -
Information on Natural Disasters Part- I Introduction
Information on Natural Disasters Part- I Introduction Astrology is the one that gave us the word ‘disaster’. Many believe that when the stars and planets are in malevolent position in our natal charts bad events or bad things would happen. Everyone one of us loves to avoid such bad things or disasters. The disaster is the impact of both natural and man-made events that influence our life and environment that surrounds us. Now as a general concept in academic circles, the disaster is a consequence of vulnerability and risk. The time often demands for appropriate reaction to face vulnerability and risk. The vulnerability is more in densely populated areas where if, a bad event strikes leads to greater damage, loss of life and is called as disaster. In other sparely populated area the bad event may only be a risk or hazard. Developing countries suffer the greatest costs when a disaster hits – more than 95 percent of all deaths caused by disasters occur in developing countries, and losses due to natural disasters are 20 times greater as a percentage of GDP in developing countries than in industrialized countries. A disaster can leads to financial, environmental, or human losses. The resulting loss depends on the capacity of the population to support or resist the disaster. The term natural has consequently been disputed because the events simply are not hazards or disasters without human involvement. Types of disasters Any disaster can be classified either as ‘Natural’ or ‘man-made’. The most common natural disasters that are known to the man kind are hailstorms, thunderstorm, very heavy snowfall, very heavy rainfalls, squalls, gale force winds, cyclones, heat and cold waves, earthquakes, volcanic eruptions, floods, and droughts which cause loss to property and life. -
Volcanic Gases
ManuscriptView metadata, citation and similar papers at core.ac.uk brought to you by CORE Click here to download Manuscript: Edmonds_Revised_final.docx provided by Apollo Click here to view linked References 1 Volcanic gases: silent killers 1 2 3 2 Marie Edmonds1, John Grattan2, Sabina Michnowicz3 4 5 6 3 1 University of Cambridge; 2 Aberystwyth University; 3 University College London 7 8 9 4 Abstract 10 11 5 Volcanic gases are insidious and often overlooked hazards. The effects of volcanic gases on life 12 13 6 may be direct, such as asphyxiation, respiratory diseases and skin burns; or indirect, e.g. regional 14 7 famine caused by the cooling that results from the presence of sulfate aerosols injected into the 15 16 8 stratosphere during explosive eruptions. Although accounting for fewer fatalities overall than some 17 18 9 other forms of volcanic hazards, history has shown that volcanic gases are implicated frequently in 1910 small-scale fatal events in diverse volcanic and geothermal regions. In order to mitigate risks due 20 2111 to volcanic gases, we must identify the challenges. The first relates to the difficulty of monitoring 22 2312 and hazard communication: gas concentrations may be elevated over large areas and may change 2413 rapidly with time. Developing alert and early warning systems that will be communicated in a timely 25 2614 fashion to the population is logistically difficult. The second challenge focuses on education and 27 2815 understanding risk. An effective response to warnings requires an educated population and a 2916 balanced weighing of conflicting cultural beliefs or economic interests with risk. -
The Emergence of Magnetic Skyrmions
The emergence of magnetic skyrmions During the past decade, axisymmetric two-dimensional solitons (so-called magnetic skyrmions) have been discovered in several materials. These nanometer-scale chiral objects are being proposed as candidates for novel technological applications, including high-density memory, logic circuits and neuro-inspired computing. Alexei N. Bogdanov and Christos Panagopoulos Research on magnetic skyrmions benefited from a cascade of breakthroughs in magnetism and nonlinear physics. These magnetic objects are believed to be nanometers-size whirling cylinders, embedded into a magnetically saturated state and magnetized antiparallel along their axis (Fig. 1). They are topologically stable, in the sense that they can’t be continuously transformed into homogeneous state. Being highly mobile and the smallest magnetic configurations, skyrmions are promising for applications in the emerging field of spintronics, wherein information is carried by the electron spin further to, or instead of the electron charge. Expectedly, their scientific and technological relevance is fueling inventive research in novel classes of bulk magnetic materials and synthetic architectures [1, 2]. The unconventional and useful features of magnetic skyrmions have become focus of attention in the science and technology Figure 1. Magnetic skyrmions are nanoscale spinning magnetic circles, sometimes teasingly called “magic knots” or “mysterious cylinders (a), embedded into the saturated state of ferromagnets (b). particles”. Interestingly, for a long time it remained widely In the skyrmion core, magnetization gradually rotates along radial unknown that the key “mystery” surrounding skyrmions is in the directions with a fixed rotation sense namely, from antiparallel very fact of their existence. Indeed, mathematically the majority of direction at the axis to a parallel direction at large distances from the physical systems with localized structures similar to skyrmions are center. -
Recent Achievements in Archaeomagnetic Dating in the Iberian Peninsula: Application to Roman and Mediaeval Spanish Structures
Journal of Archaeological Science 35 (2008) 1389e1398 http://www.elsevier.com/locate/jas Recent achievements in archaeomagnetic dating in the Iberian Peninsula: application to Roman and Mediaeval Spanish structures M. Go´mez-Paccard a,*, E. Beamud b a Research Group of Geodynamics and Basin Analysis, Department of Stratigraphy, Paleontology and Marine Geosciences, Universitat de Barcelona, Campus de Pedralbes, E-08028 Barcelona, Spain b Research Group of Geodynamics and Basin Analysis, Paleomagnetic Laboratory (UB-CSIC), Institute of Earth Sciences ‘‘Jaume Almera’’, Sole´ i Sabarı´s, E-08028 Barcelona, Spain Received 18 May 2007; received in revised form 25 September 2007; accepted 8 October 2007 Abstract Archaeomagnetic studies in Spain have undergone a significant progress during the last few years and a reference curve of the directional variation of the geomagnetic field over the past two millennia is now available for the Iberian Peninsula. These recent developments have made archaeomagnetism a straightforward dating tool for Spain and Portugal. The aim of this work is to illustrate how this secular variation curve can be used to date the last use of several burnt structures from Spain. Four combustion structures from three archaeological sites with ages ranging from Roman to Mediaeval times have been studied and archaeomagnetically dated. The directions of the characteristic remanent magnetization of each structure have been obtained from classical thermal and alternating field (AF) demagnetization procedures, and a mean direction for each combustion structure has been obtained. These directional results have been compared with the new reference curve for Iberia, providing archae- omagnetic dates for the last use of the kilns. -
Reconstructing Quaternary Environments
Reconstructing Quaternary Environments Third Edition John Lowe arid Mike Walker 13 Routledge jjj % Taylor & Francis Croup LONDON AND NEW YORK Contents List offigures and tables xv Preface to the third edition xxvn Acknowledgements xxix Cover image details xxx 1 The Quaternary record 1 1 1 Introduction 1 1 2 Interpreting the Quaternary record 2 1 3 The status of the Quaternary in the geological timescale 2 1 4 The duration of the Quaternary 3 1 5 The development of Quaternary studies 5 151 Historical developments 5 152 Recent developments 7 1 6 The framework of the Quaternary 9 17 The causes of climatic change 13 1 8 The scope of this book 16 Notes 17 2 Geomorphological evidence 19 2 1 Introduction 19 2 2 Methods 19 22 1 Field methods 19 22 11 Field mapping 19 2 2 12 Instrumental levelling 20 222 Remote sensing 22 2 2 2 1 Aerial photography 22 2 2 2 2 Satellite imagery 22 2 2 2 3 Radar 23 2 2 2 4 Sonar and seismic sensing 24 2 2 2 5 Digital elevation/terrain modelling 24 2 3 Glacial landforms 26 23 1 Extent of ice cover 27 2 3 2 Geomorphological evidence and the extent of ice sheets and glaciers during the last cold stage 30 2 3 2 1 Northern Europe 30 2 3 2 2 Britain and Ireland 33 vi CONTENTS 2 3 2 3 North America 35 2 3 3 Direction of ice movement 39 2 3 3 1 Striations 40 2 3 3 2 Friction cracks 40 2 3 3 3 Ice moulded (streamlined) bedrock 40 2 3 3 4 Streamlined glacial deposits 42 2 34 Reconstruction offormer tee masses 43 2 3 4 1 Ice sheet modelling 43 2 3 4 2 Ice caps and glaciers 47 23 5 Palaeochmatic inferences using former glacier -
Archaeological Tree-Ring Dating at the Millennium
P1: IAS Journal of Archaeological Research [jar] pp469-jare-369967 June 17, 2002 12:45 Style file version June 4th, 2002 Journal of Archaeological Research, Vol. 10, No. 3, September 2002 (C 2002) Archaeological Tree-Ring Dating at the Millennium Stephen E. Nash1 Tree-ring analysis provides chronological, environmental, and behavioral data to a wide variety of disciplines related to archaeology including architectural analysis, climatology, ecology, history, hydrology, resource economics, volcanology, and others. The pace of worldwide archaeological tree-ring research has accelerated in the last two decades, and significant contributions have recently been made in archaeological chronology and chronometry, paleoenvironmental reconstruction, and the study of human behavior in both the Old and New Worlds. This paper reviews a sample of recent contributions to tree-ring method, theory, and data, and makes some suggestions for future lines of research. KEY WORDS: dendrochronology; dendroclimatology; crossdating; tree-ring dating. INTRODUCTION Archaeology is a multidisciplinary social science that routinely adopts an- alytical techniques from disparate fields of inquiry to answer questions about human behavior and material culture in the prehistoric, historic, and recent past. Dendrochronology, literally “the study of tree time,” is a multidisciplinary sci- ence that provides chronological and environmental data to an astonishing vari- ety of archaeologically relevant fields of inquiry, including architectural analysis, biology, climatology, economics, -
Scale and Structure of Time-Averaging (Age Mixing) in Terrestrial Gastropod Assemblages from Quaternary Eolian Deposits of the E
Palaeogeography, Palaeoclimatology, Palaeoecology 251 (2007) 283–299 www.elsevier.com/locate/palaeo Scale and structure of time-averaging (age mixing) in terrestrial gastropod assemblages from Quaternary eolian deposits of the eastern Canary Islands ⁎ Yurena Yanes a, , Michał Kowalewski a, José Eugenio Ortiz b, Carolina Castillo c, Trinidad de Torres b, Julio de la Nuez d a Department of Geosciences, Virginia Polytechnic Institute and State University, 4044 Derring Hall, Blacksburg, VA, 24061, US b Biomolecular Stratigraphy Laboratory, Escuela Técnica Superior de Ingenieros de Minas de Madrid, C/ Ríos Rosas 21, 28003, Madrid, Spain c Departamento de Biología Animal, Facultad de Biología, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, s/n. 38206, La Laguna, Tenerife, Canary Islands, Spain d Departamento de Edafología y Geología, Facultad de Biología, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, s/n. 38206, La Laguna, Tenerife, Canary Islands, Spain Received 13 November 2006; received in revised form 10 March 2007; accepted 9 April 2007 Abstract Quantitative estimates of time-averaging (age mixing) in gastropod shell accumulations from Quaternary (the late Pleistocene and Holocene) eolian deposits of Canary Islands were obtained by direct dating of individual gastropods obtained from exceptionally well-preserved dune and paleosol shell assemblages. A total of 203 shells of the gastropods Theba geminata and T. arinagae, representing 44 samples (=stratigraphic horizons) from 14 sections, were dated using amino acid (isoleucine) epimerization ratios calibrated with 12 radiocarbon dates. Most samples reveal a substantial variation in shell age that exceeds the error that could be generated by dating imprecision, with the mean within-sample shell age range of 6670 years and the mean standard deviation of 2920 years. -
Sedimentary Rocks
OCN 201 Coastal Sediments Lab Sediment Particle Size Distribution and Turbidity Flows Although this laboratory will pertain to oceanic sediments, similar processes can also be observed on land and in other aquatic systems (i.e., lakes, wetlands). This reading should supplement your understanding of the processes that affect particle size distribution across a marine system (i.e., barrier reef). Next week’s laboratory exercises will focus on demonstrating some of these principles, and give you experience in quantifying particle size distributions across a barrier reef. Sediments Sediment, by definition, is any loose or fragmented material. Hence, loose sand, shells and their fragments, dead leaves, and mud can all be categorized as sediment. All sediments have a source from which they originate. Pelagic sediments are those found in the open ocean, and whose origin cannot be traced to a specific landmass. They include red clay, radiolarian ooze, diatom ooze, and calcareous (nanofossil or foraminefera) ooze (see images of selected biogenic tests – see page 8 of Laboratory#5). Terrigenous sediments are those whose origin is traceable to a specific land (terra) area. They include a series of variously colored muds, volcanic debris, coral muds, and turbidity flow deposits. Lithogenous sediments are derived from weathering of rock (lithos) material, but their source cannot be readily identified. Red clay in the abyssal ocean is lithogenous. Much of the sediment on the sea floor of the open ocean is lithogenous clay that was transported thousands of miles from its origin. Calcareous sediments are found over oceanic rises and platforms, whereas red clays are typically distributed in the deep ocean basins. -
Chapter 10. a First Look at Nunatsiavut Kangidualuk ('Fjord') Ecosystems
Chapter 10. A first look at Nunatsiavut Kangidualuk (‘fjord’) ecosystems Lead author Tanya Brown1,2,3, Ken Reimer3, Tom Sheldon4, Trevor Bell5 1Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC; 2Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC; 3Environmental Sciences Group, Royal Military College of Canada, Kingston, ON; 4Nunatsiavut Government, Nain, NF; 5Memorial University of Newfoundland, St. John’s, NF Contributing authors S. Bentley, R. Pienitz, M. Gosselin, M. Blais, M. Carpenter, E. Estrada, T. Richerol, E. Kahlmeyer, S. Luque, B. Sjare, A. Fisk, S. Iverson Abstract Long marine inlets that are classified as either fjords or fjards indent the Labrador coast. Along the moun- tainous north coast a classic fjord landscape dominates, with deep (up to ~300 m) muddy basins separated by rocky sills and flanked by high (up to 1,000 m), steep sidewalls. In contrast, the fjards of the central and southern coast are generally shallow (150 m), irregularly shaped inlets with gently sloping sidewalls and large intertidal zones. These fjords and fjards are important feeding grounds for marine mammals and seabirds and are commonly used by Inuit for hunting and travel. Despite their ecological and socio-cultural importance, these marine ecosystems are largely understudied. The Nunatsiavut Nuluak project has, as a primary goal, to undertake baseline inventories and comparative assessments of representative marine ecosystems in Labrador, including benthic and pelagic community composition, distribution and abun- dance, fjord processes, and oceanographic conditions. A case study demonstrating ecosystem resilience to anthropogenic disturbance is examined. This information provides a foundation for further research and monitoring as climate change and anthropogenic pressures alter recent baselines.