1960- Harry H. Hess came up with idea that the oceanic crust is arranged between the mid ridge and it spread throughout the other ridges.
Earthquakes and Subduction Zones Lab Amy Paret Mrs. Igo 9th Grade Periods 3 and 4 Even Date: 2/14/13 Background Research: This lab uses earthquake data to construct profiles of two convergent boundaries: the Tonga Trench and the Peru-Chile Trench. Where two tectonic plates converge, if one or both of the plates is an oceanic lithosphere, a subduction zone will form. When crust is formed at a mid-ocean ridge, it is hot and buoyant meaning it has a low density. As it spreads away from the ridge and cools and contracts, or becomes denser, it is able to sink into the hotter underlying mantle. When two oceanic plates collide, the younger of the two plates, because it is less dense will ride over the edge of the older plate. The density of the
One of these creatures are the yeti crabs. These crabs live near the thermal vents at the bottom of the deep sea. Their white color could be due to their obscured environment. There is a reason these crabs are called “yeti crabs”. Yetis have hair, so this would represent the crab’s distinct features. As said in the article, these crabs are “Dubbed ‘yeti crabs’ for their hairy chests and legs, these creatures are new to science” (p.3). This has grown on the crabs over many years to adapt to the thermal vents around its living space. The yeti crab lives in a mixed climate where it is very hot and very cold at the same time. When these two temperatures collide, “chemical reactions produce an array of mineral compounds, which many organisms consider food” (p.2). Animals such as the yeti crab depend on chemistry rather than photosynthesis. Since these crabs are new to science and new to the studies of scientists, they “aren’t sure but conjecture that mineral-eating bacteria might grow on the crabs’ hairs and that the crabs might scoop up the bacteria” (p.3). This differs from the other crabs in the world. Maybe the more the yeti crabs live near the thermal vents, they will adapt even more and evolve
The theory of plate tectonics was first developed by Alfred Wegener. He concluded that the continents seem to have a similar shape and could potentially fit together. This suggested that they were at one time joined together as part of 2 super continents called Gondwanaland and Laurasia was in the
It is believed that this volcanic area was caused by a localised hot spot within the Pacific plate. A concentration of radioactive elements inside of the mantle may have caused this hot spot to develop. The hot spot is stationary so as the Pacific plate moves over it a line of volcanoes are made. This is more proof that the Earth’s crust is moving as suggested by Wegener.
The heavier oceanic plate is being pushed under and melted so that it will rise up the lithosphere as magma and gasses to cause an
Studies of the age of molten rock in the ocean crust confirm the magnetic data. Molten rock contains radioactive isotopes used to calculate the time of the eruption. Rocks near the Mid- Atlantic Ridge, in addition to current like structures happened to be rather young, only some million years aged or a lesser amount (Trefil & Hazen, 2010). Rocks gathered one after another farthest from the range established them to be in turn older. Up to date evidence on charting the surfaces of oceans, maps of rock magnetism, and data on the age of rock indicate to countless expert that the span of the Atlantic Ocean for all intents and purposes is
3) In the Pacific Ocean, where is the oldest oceanic crust located (generally)? The oldest oceanic crust is located along the continental margin, Which is composed mainly of the continental shelf, continental slope and continental rise. 4) In the Pacific Ocean, where is the youngest oceanic crust located? The youngest oceanic crust is located along the mid-ocean ridges where new crust is formed when the old crust is pushed away from mid – ocean ridges as a result of the seafloor spreading.
One evidence of this theory is molten material. Molten Material is magma erupting from mid-ocean ridges. Alvin the submarine found weird rocks shaped like pillows or toothpaste. This tells us this magma cools quickly underwater. Another type of evidence are magnetic stripes. Magnetic stripes are patterns in the ocean floor to prove Earth’s magnetic field has reversed itself in history. Scientist also looked at the “magnetic memory” of the rocks. Scientist drilled pipes through water to drill holes into the ocean floor. Scientists discovered that the older rocks were further away and younger rocks were closer. Those were the three types of evidence that scientist used to support the theory of Sea Floor Spreading.
In this episode of the BBC documentary series, “The Blue Planet: Open Ocean,” we were able to explore the abundance and complications of the open ocean, the pelagic zone. Over 60% of our planet is covered by the ocean, yet the deep sea is largely still unknown. We know more about the moon than what we know about the deep ocean. The temperature and the level of sunlight decrease as the depth increases. The ocean may appear uniform from the surface, but there is several layers to the ocean. The pelagic zone contains the most area of the open ocean. The zone includes everything except for the coastal waters and the sea floor. However, even within this area, there are variation since some part is lifeless with very little amount of organisms and
STUDY GUIDE: Chaps. 2 GEOL 111G-Survey of Geology At the end of each chapter are Review Questions and Key Terms. To study for the final, be sure to know the answers (or where to find the answers) for the given review question numbers and know the definitions of the key terms indicated.
The Hawaiian Islands were created from volcanoes over the millions of years. The Islands sit on the Pacific Ocean plate and the way these islands were formed was from the hotspots in the earth’s crust and from the underwater volcanoes that soon rise to make land. There is roughly eight
Hydrothermal vents are cracks in the ocean floor that emit hot water with minerals and bacteria.
The beginning of the start of sea floor spreading in Iceland occurred about sixty million years ago when the North-Atlantic Ocean began to open. At this time, the North American plate along with the Eurasian plate moved east and westward at approximately one centimeter per year in each direction. This has created new basalt, and ninety-two percent of Iceland’s surface area is made up of basalt. The Mid-Atlantic Ridge contains a series of spreading centers showing the ridge crest, offset in numerous areas located near transform faults that illustrate the seismically active parts of fracture zones. The dating of spreading has been recorded by magnetic lineaments, with magnetic observations from the ocean floor south of Iceland being taken advantage of in the early understanding of the ideas of plate tectonics. The largest offset is the Charlie-Gibbs Fracture Zone in the south of Iceland, where it is offset at three-hundred and fifty kilometers. To the north of this area is where the ridge is relatively straight and the depth of the water decreases at a constant rate towards Iceland. At
Further development and support of the “Continental Drift Theory” in the 1960s After World War 2, the U.S. Office of Naval Research intensified efforts in ocean-floor mapping, leading to the discovery of the Mid-Atlantic Ridge to be part of a continous system of mid-oceanic ridges on all ocean floors, prompting Harry H. Hess to suggest the theory of sea-floor spreading. The oldest fossils found in ocean sediments were only 180 million years old and little sediment were accumulated on the ocean floor. Thus, he suggested that seafloors were no more than a few hundred million years old, significantly younger than continental land due to