The buy custom essays online History of Plate Tectonics

Introduction.

Plate tectonics, centered within just the formerly theory of continental drift proposed by Alfred Wegener may just be effectively buy custom essays online by far the most significant geological theories at any time created. This essay aims to buy custom essays online assessment the evolution from the theory due to the fact it has progressed from Wagener’s work to the present buy custom essays online.

Continental drift basic principle

This concept was espoused by Alfred Wegener in 1912. In accordance to Torsvik & Cocks (2012), Wegener, a German meteorologist came up with the proposal that all the continents initially formed a single super-continent which he called Pangea, which was surrounded by a vast ocean called Panthalassa. This supercontinent later drifted apart forming the present day continents. Wegener’s dependent mostly his idea inside of the similarity between the coastlines on opposite sides from the Atlantic Ocean. He further expanded his principle to the premise that Permian flora as well as carboniferous fossils were found in South Africa, South America, India, Madagascar, Australia and Eastern Antarctica only and nowhere else leading him to hypothesize that these continents, now separated by oceans, were at one point joined together. Wegener hypothesized that the continents consist principally of lighter rocks resting on heavier crustal materials and that their relative position is not fixed, but are slowly moving at the rate of approximately a yard per century. He therefore postulated a lateral movement of continents (Torsvik & Cocks, 2012) buy custom essays online.

A huge criticism of Wegener idea is that there was no plausible mechanism to explain the lateral movement on the continents. Further, it would have been expected that due for your lateral movements, there would have been physical evidence of massive thrust faults under the margins of continents, of which none existed further casting doubts on this plan.

Rolf, Coltice & Tackley (2012) affirms, and so do many researchers in this field that the fact that Wagener based much of his arguments relating to the apparently superficial similarity of symmetry for the coastlines, especially of South America and the West Coast of Africa further weakens his notion buy custom essays online. Such a match can only be identified at the continental shelf level hence basing it on coastlines is inherently flawed.

It appears that the big reason why there was much resistance to this idea is due to the fact that much of Wegener’s do the trick buy custom essays online was theoretical in that he dwelt so much on building theories out of his observation as opposed to being empirical which would have involved quantitative applications to support his arguments.

Contemporary plate tectonics principle.

Significant technological advances around the field of geological research especially during and after the Second World War yielded new data which led into the rejection of your vertical movements as proposed by Wegener. As Rolf et al. (2012) buy custom essays online succinctly puts it, three main discoveries provided the critical stepping stones with the development on the wider thought of Plate Tectonics, which was largely formulated between 1965 and 1968; Studies within the bathymetry of the ocean floor revealed massive ridges filled with magma from which it was believed the seafloor was spreading, mapping for the earth’s magnetic fields revealed irregular reversals on the magnetic fields polarity while studies within the paleomagnetic data from rocks of the same age from different continents showed different location of poles while that from rocks from different age from same location showed apparent reversal in polarity. The theory arose out of an attempt by geologists to explain these occurances.

According to Rolf et al. (2012), this theory postulates that the earth lithosphere is manufactured up of plates that move relative to each other across the earth. These lithospheric plates consist of seven large and 18 smaller plates that diverge, converge and slip earlier a single another along their boundaries. These plates can be either continental or oceanic or a combination of both and lie atop a layer of partly molten rock called the athenosphere.

The continental plates are chiefly buy custom essays online developed up of granite and are lighter while the oceanic plates are done up of basalt and are denser. The continental plates hence float on top with the oceanic ones high up for that earth’s mantle. The interaction of these plates forms various types of plate boundaries; convergence boundaries are formed when plates collide/push against each other. Depending on the type of plates colliding, various features may be formed, for instance oceanic to oceanic plate convergence leads to formation of volcanic islands inside ocean, oceanic to continental convergence successes into volcanoes along the continental edges while continental to continental convergence leads to formation of mountain ridges like the Himalayas. Divergent boundaries are formed when plates move away from each other, buy essay online safe this generally happens at mid-ocean ridges leading into the formation of new crust at these boundaries. Lastly, transform boundaries are formed when plates slide previous buy custom essays online each other, they are characterized by much seismic activity, an example is the San Andreas fault zone in California (Rolf et al., 2012).

Conclusion

Comparison of Wegener’s continental theory and the plate tectonics buy custom essays online principle bear many similarities. Wagener’s original strategy had little objective content apart from the fit across the Atlantic coupled by the fact that the driving mechanisms behind his notion were unknown. In contrast, the current basic principle is backed by hard quantitative data and advanced technology. Nevertheless, Wegener’s approach played a key part buy custom essays online with the development of plate tectonics.

Current advances in technology including seabed mapping using advanced geophysical and sonar software utilizing 3-dimensional analytics may further advance the next revolution as far as earth sciences and plate tectonics is concerned.

References

Rolf, T., Coltice, N., & Tackley, P. J. (2012). Linking continental drift, plate tectonics and the thermal state with the Earth’s mantle. Earth and Planetary Science Letters, 351, 134-146.

Torsvik, T. H., & Cocks, L. R. M. (2012). From Wegener until now: the development of our understanding of Earth’s Phanerozoic evolution (Andre Dumont medallist lecture 2012). Geologica Belgica.

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