scholarly journals Expansion-Oriented View On Origin of Oceans

Both the concepts of plate tectonics and continental drift conceive that the planet earth’s dimension, associated with its oceans, has remained unchanged throughout the past geological periods. In contrast, Hilgenberg’s model of earth expansion endorses that initially the planet was considerably small and devoid of oceans [1]. Based on earth expansion theory the author has pointed out that since the primordial condensed or small earth was devoid of oceans, initially the ocean-forming water must have been associated with the mantle, thereby turning that geosphere considerably fluid and pre-eminently suitable for planetary expansion. Expansion of the planet appears to have been caused owing to swelling up of the semi-fluid mantle in response to an external gravitational pull caused by an extra-terrestrial planetary body, probably the Moon. The primordial earth was completely covered with a relatively thin granitic crust, which, due to swelling up of the mantle developed a number of long and sinuous expansion cracks. Through these expansion cracks widespread eruption of molten magma took place spreading on both sides of the cracks to form rudimentary oceans basins. With continued expansion, the dimension of the oceans was broadened while the expansion cracks turned in to mid-oceanic ridges. Associated with expulsion of molten lava, large quantum of volatiles, chiefly constituted of water was released from the mantle that formed the ocean water while due to desiccation of the mantle, the process of expansion was eventually stopped.

Author(s):  
David A. Rothery

The Moon’s presence in the sky has long pervaded human culture in many ways. ‘The Moon’s influence on us’ considers the influence on timekeeping and how the orbits of the Moon and Earth are the origin of our calendar. Ocean tides are caused by the gravitational pull of the Moon and Sun on ocean water with the Moon’s influence being twice as strong as the solar tide. The elliptical nature of the Moon’s orbit affects lunar and solar eclipses; these are explained along with orbital recession and day-length changes. The Moon’s influence on human behaviour and wildlife is also considered, along with the potential of a more sustained lunar presence in the future.


2014 ◽  
Vol 5 (1) ◽  
pp. 135-148 ◽  
Author(s):  
P. Sudiro

Abstract. During the first half of 20th century, the dominant global tectonics model based on Earth contraction had increasing problems accommodating new geological evidence, with the result that alternative geodynamic theories were investigated. Due to the level of scientific knowledge and the limited amount of data available in many scientific disciplines at the time, not only was contractionism considered a valid scientific theory but the debate also included expansionism, mobilism on a fixed-dimension planet, or various combinations of these geodynamic hypotheses. Geologists and physicists generally accepted that planets could change their dimensions, although the change of volume was generally believed to happen because of a contraction, not an expansion. Constant generation of new matter in the universe was a possibility accepted by science, as it was the variation in the cosmological constants. Continental drift, instead, was a more heterodox theory, requiring a larger effort from the geoscientists to be accepted. The new geological data collected in the following decades, an improved knowledge of the physical processes, the increased resolution and penetration of geophysical tools, and the sensitivity of measurements in physics decreased the uncertainty level in many fields of science. Theorists now had less freedom for speculation because their theories had to accommodate more data, and more limiting conditions to respect. This explains the rapid replacement of contracting Earth, expanding Earth, and continental drift theories by plate tectonics once the symmetrical oceanic magnetic striping was discovered, because none of the previous models could explain and incorporate the new oceanographic and geophysical data. Expansionism could survive after the introduction of plate tectonics because its proponents have increasingly detached their theory from reality by systematically rejecting or overlooking any contrary evidence, and selectively picking only the data that support expansion. Moreover, the proponents continue to suggest imaginative physical mechanisms to explain expansion, claiming that scientific knowledge is partial, and the many inconsistencies of their theory are just minor problems in the face of the plain evidence of expansion. According to the expansionists, scientists should just wait for some revolutionary discovery in fundamental physics that will explain all the unsolved mysteries of Earth expansion. The history of the expanding-Earth theory is an example of how falsified scientific hypotheses can survive their own failure, gradually shifting towards and beyond the limits of scientific investigation until they become merely pseudoscientific beliefs.


2019 ◽  
Vol 215 (8) ◽  
Author(s):  
Romain Tartèse ◽  
Mahesh Anand ◽  
Jérôme Gattacceca ◽  
Katherine H. Joy ◽  
James I. Mortimer ◽  
...  

AbstractThe Moon is the only planetary body other than the Earth for which samples have been collected in situ by humans and robotic missions and returned to Earth. Scientific investigations of the first lunar samples returned by the Apollo 11 astronauts 50 years ago transformed the way we think most planetary bodies form and evolve. Identification of anorthositic clasts in Apollo 11 samples led to the formulation of the magma ocean concept, and by extension the idea that the Moon experienced large-scale melting and differentiation. This concept of magma oceans would soon be applied to other terrestrial planets and large asteroidal bodies. Dating of basaltic fragments returned from the Moon also showed that a relatively small planetary body could sustain volcanic activity for more than a billion years after its formation. Finally, studies of the lunar regolith showed that in addition to containing a treasure trove of the Moon’s history, it also provided us with a rich archive of the past 4.5 billion years of evolution of the inner Solar System. Further investigations of samples returned from the Moon over the past five decades led to many additional discoveries, but also raised new and fundamental questions that are difficult to address with currently available samples, such as those related to the age of the Moon, duration of lunar volcanism, the lunar paleomagnetic field and its intensity, and the record on the Moon of the bombardment history during the first billion years of evolution of the Solar System. In this contribution, we review the information we currently have on some of the key science questions related to the Moon and discuss how future sample-return missions could help address important knowledge gaps.


2018 ◽  
Vol 156 (2) ◽  
pp. 182-207 ◽  
Author(s):  
G. MEINHOLD ◽  
A. M. CELÂL ŞENGÖR

AbstractPalaeogeography is the cartographic representation of the past distribution of geographic features such as deep oceans, shallow seas, lowlands, rivers, lakes and mountain belts on palinspastically restored plate tectonic base maps. It is closely connected with plate tectonics which grew from an earlier theory of continental drift and is largely responsible for creating and structuring the Earth's lithosphere. Today, palaeogeography is an integral part of the Earth sciences curriculum. Commonly, with some exceptions, only the most recent state of research is presented; the historical aspects of how we actually came to the insights which we take for granted are rarely discussed, if at all. It is remarkable how much was already known about the changing face of the Earth more than three centuries before the theory of plate tectonics, despite the fact that most of our present analytical tools or our models were unavailable then. Here, we aim to present a general conspectus from the dawn of ‘palaeogeography’ in the 16th century onwards. Special emphasis is given to innovative ideas and scientific milestones, supplemented by memorable anecdotes, which helped to advance the theories of continental drift and plate tectonics, and finally led to the establishment of palaeogeography as a recognized discipline of the Earth sciences.


Author(s):  
Naomi Oreskes

Plate tectonics is the unifying theory of modern geology. This theory, which holds that the major features of the earth’s surface are created by horizontal motions of the continents, has been hailed as the geological equivalent of the “theory of the Bohr atom in its simplicity, its elegance, and its ability to explain a wide range of observation,” in the words of A. Cox. Developed in the mid-1960s, plate tectonics rapidly took hold, so that by 1971, Gass, Smith, and Wilson could say in their introductory textbook in geology: . . . During the last decade, there has been a revolution in earth sciences . . . which has led to the wide acceptance that continents drift about the face of the earth and that the sea-floor spreads, continually being created and destroyed. Finally in the last two to three years, it has culminated in an all-embracing theory known as “plate tectonics.” The success of plate tectonics theory is not only that it explains the geophysical evidence, but that it also presents a framework within which geological data, painstakingly accumulated by land-bound geologists over the past two centuries, can be fitted. Furthermore, it has taken the earth sciences to the stage where they can not only explain what has happened in the past, and is happening at the present time, but can also predict what will happen in the future. . . . Today moving continents are a scientific fact. But some forty years before the advent of the theory of plate tectonics, a very similar theory, initially known as the “displacement hypothesis,” was proposed and rejected by the geological fraternity. In 1912, a German meteorologist and geophysicist, Alfred Wegener, proposed that the continents of the earth were mobile; in the decade that followed he developed this idea into a full-fledged theory of tectonics that was widely discussed and debated and came to be known as the theory of continental drift. To a modern geologist, raised in the school of plate tectonics, Wegener’s book, The Origin of Continents and Oceans, appears an impressive and prescient document that contains many of the essential features of plate tectonic theory.


2014 ◽  
Vol 51 (3) ◽  
pp. v-viii ◽  
Author(s):  
Ali Polat

John Tuzo Wilson (1908–1993) was one of the greatest Canadian scientists of the 20th century. His contributions to Earth Sciences, leading the formulation of the theory of plate tectonics, have revolutionized our understanding of how the planet Earth works and evolved over the past 4 billion years. This 50th anniversary special issue of the Canadian Journal of Earth Sciences is dedicated in honour of John Tuzo Wilson, who inspired tens of thousands of students all around the world to study the Earth. This special issue contains 12 papers dealing with various aspects of the “Wilson Cycle” in the geologic record, plate tectonics, mantle plumes, and how John Tuzo Wilson accepted “continental drift” and formulated the theory of plate tectonics. The contributions have mostly been made by geoscientists who directly or indirectly associated with John Tuzo Wilson and have contributed significantly to the plate tectonics paradigm.


1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.


2019 ◽  
Vol 64 (8) ◽  
pp. 762-776
Author(s):  
E. M. Galimov

This article discusses some features of geochemistry of the Earth and the Moon, which manifests the specificity of the mechanism of their formation by fragmentation of protoplanetary gas-dust condensation (Galimov & Krivtsov, 2012). The principal difference between this model and other hypotheses of the Earth-Moon system formation, including the megaimpact hypothesis, is that it assumes the existence of a long stage of the dispersed state of matter, starting with the formation of protoplanetary gas-dust condensation, its compression and fragmentation and ending with the final accretion to the formed high-temperature embryos of the Earth and the Moon. The presence of the dispersed state allows a certain way to interpret the observed properties of the Earth-Moon system. Partial evaporation of solid particles due to adiabatic heating of the compressing condensation leads to the loss of volatiles including FeO. Computer simulations show that the final accretion is mainly performed on a larger fragment (the Earth’s embryo) and only slightly increases the mass of the smaller fragment (the Moon embryo).This explains the relative depletion of the Moon in iron and volatile and the increased concentration of refractory components compared to the Earth. The reversible nature of evaporation into the dispersed space, in contrast to the kinetic regime, and the removal of volatiles in the hydrodynamic flow beyond the gas-dust condensation determines the loss of volatiles without the effect of isotopes fractionation. The reversible nature of volatile evaporation also provides, in contrast to the kinetic regime, the preservation of part of the high-volatile components, such as water, in the planetary body, including the Moon. It follows from the essence of the model that at least a significant part of the Earth’s core is formed not by segregation of iron in the silicate-metal melt, but by evaporation and reduction of FeO in a dispersed medium, followed by deposition of clusters of elemental iron to the center of mass. This mechanism of formation of the core explains the observed excess of siderophilic elements in the Earth’s mantle. It also provides a plausible explanation for the observed character of iron isotopes fractionation (in terms of δ57Fe‰) on Earth and on the Moon. It solves the problem of the formation of iron core from initially oxide (FeO) form. The dispersed state of the substance during the period of accretion suggests that the loss of volatiles occurred during the time of accretion. Using the fact that isotopic systems: U–Pb, Rb–Sr, 129J–129Xe, 244Pu–136Xe, contain volatile components, it is possible to estimate the chronology of events in the evolution of the protoplanetary state. As a result, agreed estimates of the time of fragmentation of the primary protoplanetary condensation and formation of the embryos of the Earth and the Moon are obtained: from 10 to 40 million years, and the time of completion of the earth’s accretion and its birth as a planetary body: 110 – 130 million years after the emergence of the solar system. The presented interpretation is consistent with the fact that solid minerals on the Moon have already appeared at least 60 million years after the birth of the solar system (Barboni et al., 2017), and the metal core in the Earth and in the Moon could not have formed before 50 million years from the start of the solar system, as follows from the analysis of the Hf-W system (Kleine et al., 2009). It is shown that the hypothesis of megaimpact does not satisfy many constraints and does not create a basis for the explanation of the geochemistry of the Earth and the Moon.


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