The earth has a history of shifting masses during the last 4.5 biullion years of its evolution, as we understand today from the  plate tectonics or the expanding earth model.  Due to shifting of masses (continental and oceanic plates) the axis of rotation would also change and so would the equator. Thus concentration of mass along the equatorial region would depend upon the "then" axis of rotation. Hence palaeo-bulges should be expected at sites representing the palaeo-equatorial regions of the earth. How can we locate these palaeo bulges?
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No, it is my professional geological opinion that there are no 'paleo-bulges'. However, the present one was bigger in the past than it is today. Why? Because the Earth rotated faster when it was formed, and is constantly slowing down very slowly. For example, the day was only 18 hours long about 400 million years ago, the time of the first fish.
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I love this type of science - this is the only science that I know _-- Earth Science!\n\nIn 1963, Fred Vine, Drummond Matthews, and others found that the crust surrounding the midocean ridges showed alternating bands -- each band magnetized with a polarity opposite the surrounding bands. They suggested that as new sea-floor crust was formed around the rift in the midocean ridge, it magnetized differently, depending upon the polarity of the planet at that time. This supported the theory that Harry Hess had put forth, that the ocean progressivley widens as new sea floor is created along a crack that follows the crest of midocean ridges.\n\nIn 1966, earth scientists first identified the Jaramillo Event, the wholesale reversal of Earth's magnetic fields some 900,000 years ago. This confirmed the theory that Earth's magnetic field had flip-flopped through the planet's life, and it made Matthews and Vine's 1963 finding quite clear. They realized that the pattern of reversals matched perfectly the magnetic profile they had compiled of the sea floor. This discovery, together with data from a 1964 research vessel, transformed the field of geology. It confirmed sea-floor spreading as hypothesized by Hess, and thus "continental drift," originally proposed by Alfred Wegener back in 1912. It convinced many that plate tectonics was the best theory to unify nearly all the previously accumulated, but disjoint geological data.
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That's a lot of questions...\n\nThe land wouldn't be completely covered but the sea level would rise about 200ft so just about all coastal areas would be completely flooded. Obviously everything above that altitude would still be ok but the population would be squeezed into a much smaller area.\n\nMillions of years ago the climate was much warmer and warm ocean currents circled Antarctica which meant that it was totally ice-free and inhabited by rich plant and animal life. At this time the sea level was generally much higher than it is today. At other times, during Ice Ages, much more water was locked up as ice at the Poles and the sea level was much lower than at present.\n\nNo-one knows what is under every part of the Antarctic ice but people have drilled down to the rock in a number of places. Any remains of lost civilisations or other such surface features are likely to have been crushed and ground to dust by the weight of millions of tons of ice. It is known that there are large coal deposits left over from the compacted remains of the plants that once thrived there and there are other mineral deposits as well. At least one prehistoric lake has also been found - frozen solid, of course beneath hundreds of feet of ice and snow.\n\nThe magnetic poles are gradually shifting all the time and many maps such as UK Ordnance Survey maps indicate the rate of variation... on the most recent map I have it states that Magnetic North is moving by 09' East each year. Historically a number of "polar reversals" have been recorded where basically the magnetic north and south poles swap places (282 times in the last 10 million years).  This seems to happen quite suddenly and probably when the gradual shift reaches a critical balance point.\n\nThe main evidence comes from rocks produced from mid-ocean ridges which erupt as liquid magma and rapidly solidify retaining the magnetic field that they were subjected to as they hardened. From this it is possible to see that the North and South Poles have "flipped" and quite regular intervals for millions of years - and in fact in geological terms we seem about due for another such an event.\n\nIt appears that when the poles swap in this way there are often several rapid exchanges before the new arrangement is reached so that the North Pole may go N-S-N-S-N-S in a short space of time before sticking at the new reversed state. This would probably cause all sorts of temporary problems such as disruption to navigation and possibly interference with radio signals and so forth. As some of the rocks of the Earth contain a certain amount of iron which is susceptible to magnetic influences there may also be earthquakes or volcanic eruptions.
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The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed. This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle. \nThe plates are made of rock and drift all over the globe; they move both horizontally (sideways) and vertically (up and down). Over long periods of time, the plates also change in size as their margins are added to, crushed together, or pushed back into the Earth's mantle. These plates are from 50 to 250 miles (80 to 400 km) thick. \nThe map of the Earth is always changing; not only are the underlying plates moving, but the plates change in size. Also, the sea level changes over time (as the temperature on Earth varies and the poles melt or freeze to varied extents), covering or exposing different amounts of crust. \nThe current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate, and the Scotia plate.
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Tides on earth\nThe gravitational attraction that the Moon exerts on Earth is the cause of tides in the sea. The tidal flow period, but not the phase, is synchronized to the Moon's orbit around Earth. The tidal bulges on Earth, caused by the Moon's gravity, are carried ahead of the apparent position of the Moon by the Earth's rotation, in part because of the friction of the water as it slides over the ocean bottom and into or out of bays and estuaries. As a result, some of the Earth's rotational momentum is gradually being transferred to the Moon's orbital momentum, resulting in the Moon slowly receding from Earth at the rate of approximately 38 millimetres per year. At the same time the Earth's rotation is gradually slowing, the Earth's day thus lengthens by about 15 µs every year. A more detailed discussion follows in the section titled Earth & Moon\n\nEarth & Moon\nTidal effects\n  \nThe tides on Earth are mostly generated by the Moon's gravitation, with a less significant contribution by the Sun. These gravitational effects are specifically manifested as tidal forces. The combination of the two is responsible for spring and neap tides. Two tidal bulges, one in the direction of the Moon, and one in the opposite direction (figure 1) form as a result of the tidal forces. The buildup of these bulges and their movement around the earth causes an energy loss due to friction. The energy loss decreases the rotational energy of the Earth.\n\nSince the Earth spins faster than the Moon moves around it, the tidal bulges are dragged along with the Earth's surface faster than the Moon moves, and move "in front of the Moon" (figure 2). Because of this, the Earth's gravitational pull on the Moon has a component in the Moon's "forward" direction with respect to its orbit. This component of the gravitational forces between the two bodies acts like a torque on the Earth's rotation, and transfers angular momentum and rotational energy from the Earth's spin to the Moon's orbital movement.\n\n \nGalileo spacecraft took this picture of the Earth-moon system \nLunar librationBecause the Moon is accelerated in the forward direction, it moves to a higher orbit. As a result, the distance between the Earth and Moon increases, and the Earth's spin slows down (figure 3). Measurements reveal that, at present, the Moon's distance to the Earth increases by 38 mm per year (lunar laser ranging experiments with laser reflectors are used to determine this). Atomic clocks also show that the Earth's day lengthens by about 15 microseconds (µs) every year.\n\nThis effect is expected to continue until the spin of the Earth has slowed to match the orbital period of the Moon. At that point the tidal effect of the Sun will dominate, further slowing the Earth and thereafter causing the orbit of the Moon to steadily shrink. However these effects would not be expected to occur until long after the Sun has become a red giant.\n\nHowever, the formation of tidal bulges on Earth is irregular and not directly related to the frictional energy loss which accompanies the tides. For example, continents on Earth may cause an increase in frictional energy losses and hamper the buildup of tidal bulges (figure 4).\n\nThe lunar surface is also subjected to tides from earth, and rises and falls by around 10 cm over 27 days. The lunar tides comprise a mobile component, due to the Sun, and a selenographically fixed one, due to Earth (the Moon keeps the same face turned to the Earth, but not to the Sun). The vertical motion of the Earth-induced component comes entirely from the Moon's orbital eccentricity; if the Moon's orbit were perfectly circular, there would be solar tides only. The magnitude of the Moon's tides corresponds to a Love number of 0.0266, and supports the idea of a partially melted zone around its core. Moonquake waves lose energy below 1,000 kilometres in depth, and thi
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The reponse is related to plate tectonics. The earth crust is composed of a larger number of plates that float, very slowly of course, over the liquid interior. Continents therefore move relative to each other. When two plates meet, generally one moves under the other and it is here that we find mountains and volcanoes.\n\nWhat relation with oceans? Well, between some of the plates there is an upwelling of new magma, new crust. This is for instance the case in the middle of the Atlantic Ocean. The new crust needs room and pushes the plates on the left and right away: the Americas are moving to the west, while Europe and Africa are moving to the east. \n\nOceans (ah, at last!) are watermasses in which such upwelling of fresh crust takes place. An ocean therefore is partly in two or more different plates. On the other hand, seas are bodies of water that are on one continental plate only, or on two plates were no new crust is formed.\n\nHere is a pictures of the different continental plates:\n http://en.wikipedia.org/wiki/Image:Plates_tect2_en.svg
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SafariX Textbooks Online - Essentials of Oceanography, Eighth EditionThe existence of sea floor spreading was confirmed when the Glomar Challenger began the Deep Sea Drilling Project to sample ocean sediments and the ... \nhttp://www.safarix.com/0131635719/ch04lev1sec9\n\nSpreading of the Ocean Floor: New Evidence -- Vine 154 (3755 ...Sediment Distribution on the Mid-Ocean Ridges with Respect to Spreading of the Sea Floor. J. Ewing and M. Ewing (1967). Science 156: 1590-1592 | Abstract ... \nhttp://www.sciencemag.org/cgi/content/abstract/154/3755/1405\n\nThe Active Part of Charlie-Gibbs Fracture Zone: A Study Using Sonar and Other Geophysical Techniques … - group of 2 »\nR Searle - J. Geophys. Res, 1981 - osti.gov \n... SEA-FLOOR SPREADING; ATLANTIC OCEAN;GEOLOGIC FAULTS;OCEANIC CRUST;PLATE\nTECTONICS;SEDIMENTS;SONAR. ... geophysical instruments has revealed new information ...\nhttp://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6458102\n\nContinental breakup and the onset of ultraslow seafloor spreading off Flemish Cap on the Newfoundland rifted margin \nhttp://geology.geoscienceworld.org/cgi/content/abstract/32/1/93\n\nTransition from continental break-up to punctiform seafloor spreading: how fast, symmetric and … - group of 5 »\nG Corti, JW Van Wijk, M Bonini, D Sokoutis, S … - Geophys. Res. Lett, 2003 -\n http://scholar.google.com/url?sa=U&q=http://www-pord.ucsd.edu/~wilbert/JOLANTE/bestanden%2520Jolante/Corti2003.pdf\n\nI could not find much on it but I hope these links help. If not, just put what your looking for into the search bar to do more research on it. good luck.
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This section summarizes advances in our understanding of Venus since 1978 and outstanding problems that require resolution by future missions. The decade following the 1978 report witnessed the acquisition of the first geophysical data relevant to the planet's interior. The Pioneer Venus radar altimeter provided a global topographic map, and radio tracking of the orbiter supplied gravity data over limited regions. In contrast to Earth, Venus's gravity and topography are highly correlated, and interpretations of the combined data may involve mantle and lithosphere dynamical processes peculiar to Venus. The Pioneer Venus magnetometer placed a strict upper limit on any internally generated global magnetic field; the implications of this for the planet's internal structure and theories of the geodynamo are profound and include the possibility that the core is completely liquid. \n\nThe Soviet Venera 15 and 16 radar missions, as well as high-resolution Earth-based radar observations, have revealed a complex tectonic history for the Venus surface. There are unique features visible in these images that could have important implications for internal processes. Although the impact crater record provides a broad constraint on surface ages, limited resolution (1 to 2 km) has prevented identification of the complete record with certainty. The Magellan mission should provide resolution sufficient to characterize the cratering history and to search for a possible relic crater population prior to climatic instability. The mission should also test hypotheses about the timing, style, and rate of surface-modification processes including erosion, possible fossil river beds, volcanic resurfacing, and perhaps plate tectonics. \n\nExperiments to determine major element composition of surface rocks were performed by seven of the Soviet Venera landers. The elemental inventories are all consistent with two types of basalts: high-potassium basalt near a suspected impact feature and tholeiitic basalts in the lowland plains, similar to ocean floor basalts on Earth. \n\nNoble gas abundances in the atmosphere of Venus were measured by the Pioneer Venus and Venera probes, but the data contain serious conflicts and are subject to profound differences of interpretation. The deuterium abundance in the atmosphere was tentatively determined from the 1978 Pioneer Venus data to be 0.016. This elevated value has been a prime driver for the argument that the planet has lost a massive amount of water over the age of the solar system, although an alternative interpretation involving comet impacts is also viable. In addition, the reported abundance of water in the atmosphere has a very peculiar altitude profile when the Pioneer Venus and Venera measurements are combined. Since the water and the deuterium abundances are key quantities in understanding the evolution of the atmosphere and the planet's surface, improved abundances and height profiles are essential. \n\nGlobal changes in the composition of the Venus atmosphere have recently been shown to occur on short time scales, on the order of months or years. Analysis indicates that the global average abundance of SO2 in the visible-part of the atmosphere decreased tenfold between 1978 and 1983, perhaps as result of the recovery of the atmosphere from a massive volcanic eruption. \n\nPioneer Venus provided important information on ionospheric and solar wind interactions, atmospheric thermal structure, zonal and meridional circulation, and planetary-scale waves and tides. The Soviet VEGA balloons collected additional information about the dynamics of the atmosphere of cloud level. \n\nSCIENTIFIC OBJECTIVES\n\nMeasurements from Pioneer Venus, Venera; VEGA, and ground-based investigations have provided a quantitative data base but have also raised fundamental issues concerning the planet's interior, surface, and atmosphere that demand further study. \n\nDetermination of the interior structure is a prim
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The best answer from the above choices: \nSlow moving convection currents within the molten aesthenosphere supply new material to the spreading centers in the earth's ocean floors and other places. These currents are thought to provide force to cause the motion of the oceanic plates, either directly, or indirectly through the mid ocean ridge building process. \n\nSubduction is only one part of the process of plate tectonics, that does provide some driving force by pulling the subducting plate downward. \n\nGravity has a role as well, as without gravity, the mid-ocean ridges would not have the weight to provide force with which to push the plates apart at the spreading centers, and the subducting plates would not have the force to pull plates. \n\nThe earth's magnetic field may have the least to do with plate tectonics, possibly no role at all.
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1.  Flat maps distort landmasses because the earth is curved and 3-dimensional.\n\n2.  The difference in elevation between two contour lines is the contour interval.\n\n3.  Time zone boundaries are not always in a straight line because of politics.  Some states/cities/provinces/etc do not want half of their population in a different time.\n\n4.  The mercator projection makes the earth at the poles as wide as the earth at the equator.  In reality the earth is wider at the equator, so the projection ends up stretching the poles out.  \n\n5.  Each contour line represents a specific elevation.  \n\n6.  The TOPEX/POSEIDON satellite sends microwaves down to the surface of the ocean.  It measures the time it takes for the microwaves to go from the satellite, bounce off the ocean, and return to the satellite.  This is to get the height of the ocean surface.  The surface height is used to predict ocean currents.
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First: Gravity is due to mass, while magnetism is due to the movement of an electric charge.  For earth, this is believed to be caused by the movement of ions within the earth, the magma near the core.\n\nSecond: The poles of a magnet were misnamed.  They named the poles of a magnet because of the direction they pointed.  However, once the properties of magnetism were truly understood, it was too late.  So, appropriately, it could be said that near the north pole is the south magnetic pole, but I'm sure most teachers would frown upon that assertion.\n\nOther notes about magnetism on earth: The earth is imperfect.  The magnetic field is not uniform, so there are variations.  Magnetic north is not geographic north in all situations.  The earth is tilted, and we don't really know the flow of the magma that causes the magnetic field all that well.  Not to mention, there is speculation that magnetic north and south may flip at some point in time, but the mechanism of this is lost on me.  It has happened a very long time ago, and is expected to happen again sometime in the future.
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There is few hints like same geology at diferernt geografic points related to the same period; \nSame fauna indicating same region or at leastthey migrated through some kind of bridge;\nObvious fit about the continents. \nWhat cause it is the tectonic movement. Dorsals have separated it and we still in movement there is measure about hom many inches we are far from Europe/AFrica and also to other continents. (Also Heigh of montains are changind)
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here is something more precise:\n\n   1. Transform boundaries occur where plates slide, or perhaps more accurately grind, past each other along transform faults. The relative motion of the two plates is either sinistral (left side toward the observer) or dextral (right side toward the observer).\n   2. Divergent boundaries occur where two plates slide apart from each other.\n   3. Convergent boundaries (or active margins) occur where two plates slide towards each other commonly forming either a subduction zone (if one plate moves underneath the other) or an orogenic belt (if the two simply collide and compress).
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that remains to be seen but glaziers have always been moving .so a deep groove is more likely \n\nit is the ice in the south Pole which should hold the most interesting secrets ,as it is a big land mass that used to be in the tropics \nmany of us believe that Atlantis could be beneath Antarctica
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One piece of evidence is the symmetry of ocean floor spreading.\n\nAnother is the way some of the continents seem to fit together like a jigsaw puzzle (the east coast of South America and the west coast of Africa, for example). \n\nYou could argue that the pattern of the Hawaiian volcanoes is evidence that the Pacific plate has travelled in a northeastenly direction over the hot spot now feeding the active volcanoes of Mauna Loa, Kilauea, and Loihi (underwater). The farther you move away from the hot spot in the southeast corner of the Hawaiian islands, the older and smaller the islands get, until you get to Kure Atoll and the seamounts beyond.
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One. It was called pangaea heres some more info:\n\nPangaea or Pangea (derived from Παγγαία, Greek for "all earth") is the name given to the supercontinent that existed during the Paleozoic and Mesozoic eras, before the process of plate tectonics separated each of the component continents into their current configuration. The name was coined by Alfred Wegener, chief proponent of Continental Drift in 1915.\n\nThe continents apparently first coalesced to form Pangaea about 300 Mya (million years ago), giving rise to several prominent mountain ranges by the process known as orogeny. Several of these ranges still exist, although they have become much lower by means of erosion. The Appalachians of eastern North America, the Atlas Mountains of North Africa, and the Urals of Eurasia are prime examples. The mantle under Pangaea's former location seemingly remained very hot even after coalescence, convection currents within the underlying magma pushing the centre of the supercontinent upward. As a result, the area that is now the continent of Africa was situated tens of meters higher than the surrounding continents.\n\nIn configuration, Pangaea was a C-shaped landmass that spread across the equator. The body of water that was enclosed within the resulting crescent has been named the Tethys Sea. Owing to Pangaea's massive size, the inland regions appear to have been very dry due to the lack of precipitation. The large supercontinent would potentially have allowed terrestrial animals to migrate freely all the way from the South Pole to the North Pole.\n\nThe vast ocean that once surrounded the supercontinent of Pangaea has been named Panthalassa. Pangaea, it seems, broke up about 180 Ma in the Jurassic Period, firstly into two supercontinents (Gondwana to the south and Laurasia to the north), thereafter into the continents as we understand them today.\n\nPangaea was not the first supercontinent. From the evidence available, scientists reconstruct that a predecessor, termed Pannotia, formed about 600 Ma, before dividing again some 50 million years later. Another, Rodinia, apparently formed approximately 1,100 Ma and divided 750 Ma.
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Sea Floor Spreading Evidence- age of land and seamounts are youngest closest to a divergeant boundary.  Magnetic anomalies are the same on both sides of the boundary.\n\nIsopotic Dating- allows geologists to correlate rocks based on radioactive isotopes present.  The ratio of radiogenic daughter isotopes to the unstable parent isotope determin how long the parent has been incorporated in that mineral.\n\nMagnetic Pole Reversals-a thing called remanent magnetism is a component of a rock.  when the rock formed it shows where the earth's magnetic field was at the time.  Measurement of the orientation by inclination angle (latitude) and declination angle (longitute) gives clues to the paleolatitude of the sample when formed.