To Reconcile Historical Geology with Isostasy: Continental Drift

1999 ◽  
Author(s):  
Naomi Oreskes
Keyword(s):  
Royal Society ◽  
Large Scale ◽  
English Language ◽  
Continental Drift ◽  
The United States ◽  
Island Arcs ◽  
Geological Time ◽  
The Earth ◽  
Geological Features ◽  
Historical Geology

Alfred Wegener (1880–1930) first presented his theory of continental displacement in 1912, at a meeting of the Geological Association of Frankfurt. In a paper entitled “The geophysical basis of the evolution of the large-scale features of the earth’s crust (continents and oceans),” Wegener proposed that the continents of the earth slowly drift through the ocean basins, from time to time crashing into one another and then breaking apart again. In 1915, he developed this idea into the first edition of his now-famous monograph, Die Entstehung der Kontinente und Ozeane, and a second edition was published in 1920. The work came to the attention of American geologists when a third edition, published in 1922, was translated into English, with a foreword, by John W. Evans, the president of the Geological Society of London and a fellow of the Royal Society, in 1924 asThe Origin of Continents and Oceans. A fourth and final edition appeared in 1929, the year before Wegener died on an expedition across Greenland. In addition to the various editions of his book, Wegener published his ideas in the leading German geological journal, Geologische Rundschau, and he had an abstract read on his behalf in the United States at a conference dedicated to the topic, sponsored by the American Association of Petroleum Geologists, in 1926. The Origin of Continents and Oceans was widely reviewed in English-language journals, including Nature, Science, and the Geological Magazine. Although a number of other geologists had proposed ideas of continental mobility, including the Americans Frank Bursey Taylor, Howard Baker, and W. H. Pickering, Wegener’s treatment was by far the best developed and most extensively researched. Wegener argued that the continents are composed of less dense material than the ocean basins, arid that the density difference between them permitted the continents to float in hydrostatic equilibrium within the denser oceanic substrate. These floatin continents can move through the substrate because it behaves over geological time as a highly viscous fluid. The major geological features of the earth, he suggested — mountain chains, rift valleys, oceanic island arcs—were caused by the horizontal motions and interactions of the continents.

Uniformitarianism and Unity

1999 ◽  
Author(s):  
Naomi Oreskes
Keyword(s):  
Steady State ◽  
Large Scale ◽  
Scientific Practice ◽  
Continental Drift ◽  
Jigsaw Puzzle ◽  
Theoretical Position ◽  
Primary Means ◽  
Historical Geology ◽  
The One

William Bowie settled on a theoretical position that accounted for isostasy and the jigsaw-puzzle fit of the continents but ignored the facts of historical geology. And yet, as we have seen, he interacted and corresponded with historical geologists, particularly with Charles Schuchert (1858–1942). Of all the American geologists who ultimately rejected the theory of drift, Schuchert was perhaps the one who engaged the problem the most seriously. As America’s foremost historical geologist, Schuchert was well placed to argue the case for or against drift, and he grappled with the question of continental connections for at least fifteen years. In the end, however, Schuchert, like Bowie, rejected continental drift. Just as Bowie argued against drift because of beliefs grounded in the exigencies of geodetic practice, Schuchert ultimately argued against drift because of beliefs grounded in the exigencies of geological practice. For Bowie, the practice was Pratt isostasy, for Schuchert, it was Uniformitarianism. Charles Schuchert rejected continental drift because he interpreted it to be incompatible with Uniformitarianism. However, he did not reject it because he could not see drift taking place, as might be supposed. Uniformitarianism has meant many things to many people, and to Charles Schuchert in the late 1920s, it meant—rightly or wrongly—an essentially steady-state earth, whose details were forever changing but whose large-scale patterns and relationships remained the same. And this seemed to him to deny the possibility of major changes in the configuration of the continents. Moreover—and perhaps more importantly—for Schuchert, as for most historical geologists, Uniformitarianism was a form of scientific practice, a means of doing historical geology. It was, in fact, the primary means of doing historical geology. For Schuchert, abandoning Uniformitarianism was nearly tantamount to abandoning historical geology altogether. Not surprisingly, he declined to do this. Like William Bowie, Charles Schuchert settled on a theoretical position that preserved his scientific practice. But whereas Bowie’s theoretical ideas had little staying power, the alternative that Schuchert embraced influenced a generation of geologists to believe that drift was not so much impossible as unnecessary.

Standards-based classroom assessments of English proficiency: A review of issues, current developments, and future directions for research

2011 ◽  
Vol 28 (3) ◽  
pp. 367-382 ◽  
Author(s):  
Lorena Llosa
Keyword(s):  
English Language Learners ◽  
Language Learners ◽  
Large Scale ◽  
English Language ◽  
Classroom Assessment ◽  
English Proficiency ◽  
The United States ◽  
High Stakes ◽  
Classroom Assessments ◽  
Key Issues

With the United States’ adoption of a standards-based approach to education, most attention has focused on the large-scale, high-stakes assessments intended to measure students’ mastery of standards for accountability purposes. Less attention has been paid to the role of standards-based assessments in the classroom. The purpose of this paper is to discuss key issues and challenges related to the use of standards-based classroom assessments to assess English language learners’ English proficiency. First, the paper describes a study of a standards-based classroom assessment of English proficiency in a large urban school district in California. Second, using this study as an example and drawing from the literature in language testing on classroom assessment, this paper highlights the major issues and challenges involved in using English proficiency standards as the basis for classroom assessment. Finally, the article outlines a research agenda for the field given current developments in the areas of English proficiency standards and classroom assessment.

scholarly journals Sequence of studying engineering and geological conditions of mineral deposits from exploration to development

2020 ◽  
Vol 7 (7) ◽  
pp. 83-91
Author(s):  
Irina V. Abaturova ◽  
◽  
Ivan A. Savintsev ◽  
Liubov A. Storozhenko ◽  
Elvina D. Nugmanova ◽  
...  
Keyword(s):  
Large Scale ◽  
Geological Environment ◽  
Geological Time ◽  
Protective Measures ◽  
Early Stages ◽  
Geological Processes ◽  
The Earth ◽  
Geological Conditions ◽  
Geological Information ◽  
Further Development

geological environment. Actively change all the components of engineering-geological conditions (EGC), formed during the long geological time: the topography, structure of rocks, hydrogeological and permafrost conditions, are formed by geological processes and, at the same time on the surface of the Earth formed a new strata of man-made structures, and often man-made deposits. The scale of technogenesis in mining today is comparable to the results of geological activity that took place over many millions of years. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures. Purpose of work. Consideration of striking examples of the dynamics of the EGC MD (from exploration to development), in order to provide methods for managing these changes. Methodology. The article considers the stages of obtaining engineering and geological information for the period of MD operation, which will solve the problems of rational use of the subsoil and protection of the geological environment. Results. For example, the number of objects marked all the stages of learning to yoke the dynamics of their changes, which led to the formation of engineering-geological processes that adversely affect the further testing of MD. Summary. The reaction of the geological environment in the development of MD is not long in coming and is expressed in the development of large-scale engineering and geological processes, which often do not allow further development of MD and threaten people's lives. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures.

Ocean Space and the Anthropocene, new notions in geosciences? – An essay

2013 ◽  
Vol 92 (2-3) ◽  
pp. 193-211 ◽  
Author(s):  
J.H. Stel
Keyword(s):  
Marine Environment ◽  
Large Scale ◽  
Industrial Revolution ◽  
High Energy ◽  
Management Style ◽  
Geological Time ◽  
Geological Time Scale ◽  
Human Scale ◽  
The Earth ◽  
The Media

AbstractTwo notions, Ocean Space and the Anthropocene, are discussed. The first is occasionally used in legal and governance literature, and in the media. The Anthropocene, however, is widely applied in the global change research community and the media. The notion of ocean space stands for a holistic, system science approach combined with 4D thinking from the ocean, and the processes within it, towards the land. Ocean space is in fact a social-ecological concept that deals with sustainability challenges which are the consequence of the complex interactions between humans and the marine environment on all scales. Ocean space is, on a human scale, impressively large. On a planetary scale, however, it is insignificant, although it has been an ancient feature of the Earth for the last four billion years or so. Yet, ocean space is a critical player in the Earth System; it is central to climate regulation, the hydrological and carbon cycles and nutrient flows, it balances levels of atmospheric gases, it is a source of raw materials vital for medical and other uses, and a sink for anthropogenic pollutants. The notion also encompasses issues such as exploration, adventure, science, resources, conservation, sustainability, etc., and should be an innovative and attractive outreach instrument for the media. Finally, it marks the fundamental change in ocean exploration in the twenty-first century in which ocean-observing systems, and fleets of robots, are routinely and continuously providing quality controlled data and information on the present and future states of ocean space. Advocates of the notion of the Anthropocene argue that this new epoch in geological time, commenced with the British industrial revolution. To date, the Anthropocene has already been subdivided into three stages. The first of these coincides with the beginning of the British industrial revolution around 1800. This transition quickly transformed a society which used natural energy sources into one that uses fossil fuels. The present high-energy society of more than seven billion people mostly with highly improved living standards and birth rates, and a global economy, is the consequence. The downside of this development comprises intensive resource and land use as well as large-scale pollution of the (marine) environment. The first stage of the Anthropocene ended abruptly after the Second World War when a new technology push occurred, leading to the second stage: ‘the Great Acceleration’ (1945-2015) followed by the third: ‘Stewards of the Earth’. Here it is concluded that the notion of the Anthropocene reflects a hierarchical or individualistic perspective, often leading to a ‘business as usual’ management style, and ‘humanises’ the geological time scale. The use of this notion is not supported. However, it is already very popular in the media. This again might lead to overestimating the role of humans in nature, and might facilitate an even more destructive attitude towards it, through the application of geo-engineering. The latter could be opening another Pandora's box. Instead we should move to a more sustainable future in which human activities are better fine tuned to the environment that we are part of. In this respect, transition management is an interesting new paradigm.

XII. Discussion

1965 ◽  
Vol 258 (1088) ◽  
pp. 137-144 ◽  
Keyword(s):  
West Coast ◽  
Continental Drift ◽  
The United States ◽  
The Body ◽  
Lateral Movement ◽  
The West ◽  
Geological Evidence ◽  
The Earth ◽  
Mid Ocean Ridge ◽  
Ocean Ridge

We have heard today about the palaeomagnetic evidence which requires the magnetic pole to wander through the body of the Earth and at the same time the continents to wander over the surface of the Earth, since Mesozoic times. We have heard the geological evidence reiterated as evidence of continental drift. Others in the past have equally ably demonstrated that this does not need to be considered evidence of continental drift. We have seen the continents authoritatively reconstructed by a computer. This seems most convincing except of course it seems necessary to discard Central America, Mexico, the Gulf of Mexico, the Caribbean Sea and the West Indies, along with their pre-Mesozoic rocks! On the other hand we have seen evidence that the ocean crust too breaks into blocks which shift relative to each other by distances up to 1400 km. A series of transcurrent faults occur along the west coast of the United States. Unmentioned is the similar fault along the east coast which extends across 600 km of the continent and out into the sea, continuing, some think, across the Atlantic to the mid-ocean ridge. On land this fault has been dated as pre-Mesozoic. It is at the same latitude as the Mendocino Escarpment off the west coast but shows right lateral movement while the latter shows predominantly left lateral movement.

IX. Discussion

1965 ◽  
Vol 258 (1088) ◽  
pp. 107-108
Keyword(s):  
Geophysical Methods ◽  
Continental Drift ◽  
Tectonic Activity ◽  
Geological Time ◽  
The Past ◽  
Current State ◽  
The Earth ◽  
Long Term Changes ◽  
History Of

Although the primary subject of the Symposium was continental drift, this is only one aspect of a larger problem. Eventually, consideration of changes in magmatic, metamorphic and tectonic activity through the history of the crust should enable us to put forward a hypothesis to account for the behaviour of the upper parts of the Earth through geological time. As had been pointed out, most geophysical methods provided information about the current state of the Earth and part of the great value of palaeomagnetic studies lay in the fact that they produced information about the past. Some information about the behaviour of possible convection cells during continental drift could be obtained from other long-term changes in the crust. The incidence of magmatic and metamorphic activity gave some indication as to the distribution of regions where there had been an unusually high accession of heat in the past.

A Discussion on volcanism and the structure of the Earth - Introductory remarks

1972 ◽  
Vol 271 (1213) ◽  
pp. 103-103 ◽  
Keyword(s):  
Upper Mantle ◽  
Royal Society ◽  
Volcanic Rocks ◽  
Direct Methods ◽  
Continental Margins ◽  
Island Arcs ◽  
Research Committee ◽  
The Past ◽  
The Earth ◽  
Oceanic Rocks

Although volcanoes provide some of nature’s most spectacular phenomena, and have been the objects of record since the earliest days of science, the accumulation of data in the past 150 years has until very recently only served to emphasize the extent of their unknown characteristics. In the last decade however there have been notable advances, both in the observation of volcanoes and volcanic rocks, and in the spectacular development of ideas about the mobility of the crust that enable volcanicity to be related to the structure of the Earth. These ideas led the Volcanic Studies Group of the Geological Society of London, and the Volcanological Research Committee of the Royal Society to consider holding a symposium to take stock of the position in the year that the Upper IVIantle Project was scheduled to end. The meeting, arranged principally to consider Tertiary and Recent volcanic rocks, fell into four groups of papers which generally coincided with the half-day sessions: oceanic rocks (Chairman, Professor J. Sutton, F.R.S.); island-arcs and continental margins (Chairman, Professor W. A. Deer, F.R.S.); and continental volcanicity (Chairmen, Professor F. H. Stewart, F.R.S. and Professor K. C. Dunham, F.R.S.). Included in the last session were papers dealing with the evidence from the only direct methods of investigation of the Upper Mantle, plutonic xenoliths and the kimberlites, and some of the papers that quantify the chemistry and kinematics of volcanicity.

I. On Professor Haughton's estimate of geological time

1878 ◽  
Vol 27 (185-189) ◽  
pp. 179-183 ◽  
Keyword(s):  
Royal Society ◽  
Principal Axis ◽  
Present Note ◽  
Geological History ◽  
Geological Time ◽  
Axis Of Rotation ◽  
The Earth ◽  
History Of ◽  
Set Up ◽  
Instantaneous Axis

In a paper recently read before the Royal Society, Professor Haughton has endeavoured by an ingenious line of argument to give an estimate of the time which may have elapsed in the geological history of the earth. The results attained by him are, if generally accepted, of the very greatest interest to geologists, and on that account his method merits a rigorous examination. The object, therefore, of the present note is to criticise the applicability of his results to the case of the earth; and I conceive that my principal criticism is either incorrect, and will meet its just fate of refutation, or else is destructive of the estimate of geological time. Professor Haughton’s argument may be summarised as follows:— The impulsive elevation of a continent would produce a sudden displacement of the earth’s principal axis of greatest moment of inertia. Immediately after the earthquake, the axis of rotation being no longer coincident with the principal axis, will, according to dynamical principles, begin describing a cone round the principal axis, and the complete circle of the cone will be described in about 306 days. Now, the ocean not being rigidly connected with the nucleus, a 306-day tide will be established, which by its friction with the ocean bed will tend to diminish the angle of the cone described by the instantaneous axis round the principal axis: in other words, the “wabble” set up by the earthquake will gradually die away.

Chaos in geophysical fluids I. General introduction

1994 ◽  
Vol 348 (1688) ◽  
pp. 431-443 ◽  
Keyword(s):  
Large Scale ◽  
Classical Mechanics ◽  
Theoretical Research ◽  
Geological Time ◽  
General Introduction ◽  
Dynamo Action ◽  
The Earth ◽  
Mhd Dynamo ◽  
Low Dimensional ◽  
Geomagnetic Polarity

Irregular buoyancy-driven flows occur in the atmospheres and fluid interiors of the Earth and other planets, and of the Sun and other stars, where they influence and often control the transfer of heat. Their presence is manifest in or implied by a wide variety of observed phenomena, including external magnetic fields generated by self-exciting magnetohydrodynamic (MHD ) dynamo action. Based on the laws of classical mechanics, thermodynamics and, in the case of electrically conducting fluids, electrodynamics, the governing mathematical equations are well known, but they are generally intractable owing to their essential nonlinearity. Computers play a key role in modern theoretical research in geophysical and astrophysical fluid dynamics, where ideas based on chaos theory are being applied in the analysis of models and the assessment of predictability. The aim of this paper is to provide a largely qualitative survey for non-specialists. The survey comprises two parts, namely a general introduction (Part I) followed by a discussion of two representative areas of research, both concerned with phenomena attributable to symmetry-breaking bifurcations caused by gyroscopic (Coriolis) forces (Part II), namely ( a ) large-scale waves and eddies in the atmospheres of the Earth, Jupiter and other planets (where, exceptionally, laboratory experiments have been influential), and ( b ) MHD dynamos. Various combinations of Faraday disc dynamos have been studied numerically as low-dimensional nonlinear electromechanical analogues of MHD dynamos, particularly in efforts to elucidate the complex time series of geomagnetic polarity reversals over geological time. The ability of the intensively studied Rikitake coupled disc dynamo system to behave chaotically appears to be a consequence of the neglect of mechanical friction, the inclusion of which renders the system structurally unstable.

scholarly journals Discursive structures in political communication

2021 ◽  
Vol 27 (3) ◽  
pp. 118-127
Author(s):  
N. A. Tribunskaya ◽  
V. D. Shevchenko
Keyword(s):  
Political Communication ◽  
Political Discourse ◽  
Large Scale ◽  
English Language ◽  
Situation Model ◽  
The United States ◽  
The Political ◽  
The Internet ◽  
Economic Significance ◽  
The Media

This article is devoted to the study of discursive structures in political sphere, represented in the English-language source Twitter of the President of the United States. The purpose of the study is to analyze the discursive structures that arise as a result of the interaction of political discourse with other types of discourses. To achieve it, the authors set the following tasks: identifying specific markers in the political discourse that characterize the presence of other discourses, analyzing the features of the communicative situation of message transmission, identifying the features of interdiscursiveness and polydiscursivity. The material for the analysis was the statements of Donald Trump on Twitter from November 1, 2019 to November 1, 2020. The authors of the article use various methods: descriptive, contextual analysis, comparative, methods of observation, content analysis and discourse analysis. The study uses the linguistic concept of the American scientist D. Himes S-P-E-A-K-I-N-G, which includes an analysis of the components of the situation: Participants, Ends, Act Sequence etc. Using the situation model in the messages, participants, their actions and other characteristics were highlighted. President is the author of the messages, while the addressee is a collective one. The same participants, depending on the context of the message, become participants of other types of discourses. The article examines such types of discourses as economic, educational, medical, which are part of political discourse. Their choice is due to the socio-economic significance of the issues of economics, education and health care in the life of society. In addition, the media function of political communication is reflected. The texts are posted on the Internet platform, due to which the political discourse is drawn into the space of the Internet discourse. The analysis made it possible to identify the features of large-scale interdiscursiveness and to highlight the levels of discursive heterogeneity.

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