The theory of plate tectonics was one of the most controversial theory ever came into light, but it was most widely accepted as it became a proven theory later in time due to may observations and physical evidences Like every scientific theory, it results from centuries of observations and compilation of many scientists’ works. It started as a speculation and had to be proven with hard evidence before being completely accepted by the scientific community.Nonetheless, we consider Alfred Wegener, a meteorologist of the beginning of the 20th century, as the father of the theory that he called at that time “the continental drift”. His book “The Origin of Continents and Oceans”, published in 1915, is considered as the beginning of modern plate tectonics, even if the theory was only widely accepted in a refined version in the 1960s.
The main idea of Wegener and others was that modern continents formed a single landmass in the past. This idea was supported by simple observations like the fact that South-American and African coastlines fit so well, or that we can find the same fossils in similar sedimentary rocks on both continents.
The theory needed an explanation for the continental drift, a kind of engine that would implement the motion of tectonic plates. The continental drift was strongly criticised during the first half of the 20th century, until WWII: during the war, the latest radar technology was used to map the seafloor. Rapidly, evidence pointing to seafloor spreading and effective plate motion was accumulated.
After the war, marine geology was developed, which led to the discovery of the subduction processunder the continental margins. Subduction was a perfect way to balance the extension observed at the mid-ocean ridges by recycling oceanic lithosphere in the mantle. Plate tectonics theory was then widely accepted among scientists because it relied on hard evidence and could explain most of the modern geological structures (ocean basins, mountain ranges, rifts etc).
Describe the mechanics of plate tectonic theory including the driving force behind plate movement.
The concept of plate tectonic theory is supported by all EXCEPT for the following evidence: geologic structure and fossil content across continents relative dating of the oceanic crust the pattern of present oceanic currents paleomagnetic analysis of the oceanic crust
In some countries, bribery is common and widely accepted. What is wrong with bribery? Why should it be illegal for American companies to pay bribes in countries where everyone else is?
Circle T if the statement is true, F if it is false.A well-tested or widely accepted economic theory is often called an economic principle or law. T F
13. What is the most widely accepted theory as to how HIV evolved? (A) Viral recombination in a chimp infected with multiple types of HIV. (B) US Government Bioweapon. (C) Antiretroviral and recreational drug use. (D) Recombination between two or more SIV strains 14. AIDS stands for Acquired Immuno Deficiency _ _. The definition of AIDS includes reduced number of _ _and a diagnosis of any of two dozen secondary (A) State, Tcells, viral infections (B) Syncytia, natural killer cells,...
To measure the tiny motion of one tectonic plate relative to another, seismologists in Iceland have set up the following interferometer-like device: A laser source producing laser light with wavelength 500 nm is set up on one side of a chasm that forms the boundary between two tectonic plates. The light is split into two beams using an angled piece of glass (acting as a "beam splitter"). One part of the beam crosses the chasm and is reflected back by...
How can you recognize and indicate the tectonic plate boundaries if they are not indicated on the map/photo? (two ways)
Los Angeles lies on the edge of the Pacific tectonic plate. It is moving west at a speed of 4.0 cm/year. At this speed, approximately how long would it take for Los Angeles to merge with Tokyo? a.2 My b.200 My c.20 My d.100 My
Tectonic plates are large segments of the Earth's crust that move slowly. Suppose one such plate has an average speed of 3.8 cm per year. (a) What distance does it move in 60 seconds at this speed? (b) What is its speed in miles per million years?
Tectonic plates are large segments of the Earth’s crust that move slowly. Suppose one such plate has an average speed of 7.2 cm per year. A) what distance does it move in 80 seconds at this speed? B) what is its speed in miles per million years?