The scientific evidence for plate tectonics
... Ocean floor spreading The need for better maps of the seafloor for submarine navigation led to a variety of studies of the seafloor that led to several amazing discoveries about the ocean floor: The ocean floor is made up almost entirely of the volcanic rock basalt (whereas the continents are made ...
... Ocean floor spreading The need for better maps of the seafloor for submarine navigation led to a variety of studies of the seafloor that led to several amazing discoveries about the ocean floor: The ocean floor is made up almost entirely of the volcanic rock basalt (whereas the continents are made ...
Press Release - English ()
... “We know the microbial biomass living under the seafloor compares to that found in the global ocean,” explained co-chief scientist Dr. Fumio Inagaki. “Yet, there are many unknowns about this mass of life deep below the seafloor, including its diversity, borders, and the factors limiting its survival ...
... “We know the microbial biomass living under the seafloor compares to that found in the global ocean,” explained co-chief scientist Dr. Fumio Inagaki. “Yet, there are many unknowns about this mass of life deep below the seafloor, including its diversity, borders, and the factors limiting its survival ...
Tracing rays through the Earth
... - focal depth of earthquake not zero - local velocity-depth distribution under a particular network - spherical symmetry not perfectly valid due to Earth’s ellipticity Travel times can be classified as “early” or “late” depending on whether the wave passes through a “slow” or “fast” region On global ...
... - focal depth of earthquake not zero - local velocity-depth distribution under a particular network - spherical symmetry not perfectly valid due to Earth’s ellipticity Travel times can be classified as “early” or “late” depending on whether the wave passes through a “slow” or “fast” region On global ...
Causes of Plate Motion - Downey Unified School District
... Great Rift Valley in Africa The Great Rift Valley lies on a continental divergent plate boundary. Divergent plate boundaries are where the earth's rigid lithosphere is being separated due to activity in the flexible asthenoshere and is creating new lithosphere. Because of this rifting process, the ...
... Great Rift Valley in Africa The Great Rift Valley lies on a continental divergent plate boundary. Divergent plate boundaries are where the earth's rigid lithosphere is being separated due to activity in the flexible asthenoshere and is creating new lithosphere. Because of this rifting process, the ...
The Mysterious Planet Earth - Japan Agency for Marine
... two plates shear past one another; and convergent, where one plate subducts beneath the other. The Japanese islands spread over four plates, the boundaries between which are capable of generating frequent large earthquakes. ...
... two plates shear past one another; and convergent, where one plate subducts beneath the other. The Japanese islands spread over four plates, the boundaries between which are capable of generating frequent large earthquakes. ...
Chlorine cycling during subduction of altered oceanic crust
... within matrices of metasedimentary and metaultramafic rocks (Franciscan Complex). Although the history of these latter rocks may have been complex, it is likely that they originally formed as extrusive material where the interaction with seawater was maximum (low-temperature alteration zone). We pre ...
... within matrices of metasedimentary and metaultramafic rocks (Franciscan Complex). Although the history of these latter rocks may have been complex, it is likely that they originally formed as extrusive material where the interaction with seawater was maximum (low-temperature alteration zone). We pre ...
volcanic
... To find the distance to an earthquake’s epicenter, scientists • Chart the lag time between preshocks and aftershocks • Use radio wave detection devices • Analyze the arrival times of P and S waves. • Analyze the arrival times of Love waves an Rayleigh waves. ...
... To find the distance to an earthquake’s epicenter, scientists • Chart the lag time between preshocks and aftershocks • Use radio wave detection devices • Analyze the arrival times of P and S waves. • Analyze the arrival times of Love waves an Rayleigh waves. ...
Sea-Floor Spreading
... Mid-Ocean Ridge – the longest chain of mountains in the world---these are divergent plate boundaries. ...
... Mid-Ocean Ridge – the longest chain of mountains in the world---these are divergent plate boundaries. ...
Snacking on Plate Tectonics
... away from each other? The frosting, or molten rock, should rise up in between the plates as the move apart. Explain that this is how new oceanic crust is formed. Explain that two continental plates can also move away from each other, but it is less common. Student Question 2. If new crust is being c ...
... away from each other? The frosting, or molten rock, should rise up in between the plates as the move apart. Explain that this is how new oceanic crust is formed. Explain that two continental plates can also move away from each other, but it is less common. Student Question 2. If new crust is being c ...
Chapter 9 web
... • The data on the _________ of seafloor sediment confirmed what the seafloor spreading hypothesis predicted. • The ________est oceanic crust is at the ridge crest (middle), and the ________est oceanic crust is at the continental margins (edges). ...
... • The data on the _________ of seafloor sediment confirmed what the seafloor spreading hypothesis predicted. • The ________est oceanic crust is at the ridge crest (middle), and the ________est oceanic crust is at the continental margins (edges). ...
Chapter 4
... The East African Rift, from Ethiopia to Kenya, is part of a divergent boundary, but you can see how the crust has subsided relative to the blocks at the edge of the rift ...
... The East African Rift, from Ethiopia to Kenya, is part of a divergent boundary, but you can see how the crust has subsided relative to the blocks at the edge of the rift ...
The Chemistry of Seawater Chapter 5-6
... i. Carbon 1. Actually driven by carbonate chemistry and the balance between the oceans and atmosphere, and by the effects of biology on the inorganic carbon 2. “Solubility Pump” is simply the “pumping” of carbon from the surface to depth by the change in solubility as pressure increases and temperat ...
... i. Carbon 1. Actually driven by carbonate chemistry and the balance between the oceans and atmosphere, and by the effects of biology on the inorganic carbon 2. “Solubility Pump” is simply the “pumping” of carbon from the surface to depth by the change in solubility as pressure increases and temperat ...
chpt 17 continental drift
... The main problems with it were: The age of the Earth would have to be billions of years, not just thousands of years. At the time, scientists believed it was only 6000 to 400 million years old. More importantly, Wegner could not explain HOW the plates moved. ...
... The main problems with it were: The age of the Earth would have to be billions of years, not just thousands of years. At the time, scientists believed it was only 6000 to 400 million years old. More importantly, Wegner could not explain HOW the plates moved. ...
distribution of oceans and continents
... to find the best fit of the Atlantic margin was presented by Bullard in 1964. It proved to be quite perfect. The match was tried at 1,000fathom line instead of the present shoreline. Rocks of Same Age Across the Oceans The radiometric dating methods developed in the recent period have facilitated co ...
... to find the best fit of the Atlantic margin was presented by Bullard in 1964. It proved to be quite perfect. The match was tried at 1,000fathom line instead of the present shoreline. Rocks of Same Age Across the Oceans The radiometric dating methods developed in the recent period have facilitated co ...
Lecture PDF
... Plate motion is driven by slow convection (heat-generated) currents flowing in the mantle. Most of the heat that drives the plates is generated by the decay of radioactive elements within Earth. ...
... Plate motion is driven by slow convection (heat-generated) currents flowing in the mantle. Most of the heat that drives the plates is generated by the decay of radioactive elements within Earth. ...
PRESENTATION NAME
... secreted by the phytoplanktonphytoplankton are eaten by protozoa protozoa & phytoplankton are eaten by zooplankton eaten by fish passing the carbon through the food chain and into animals like seals & polar bears • When any of these organisms die without then being consumed, or when they defecat ...
... secreted by the phytoplanktonphytoplankton are eaten by protozoa protozoa & phytoplankton are eaten by zooplankton eaten by fish passing the carbon through the food chain and into animals like seals & polar bears • When any of these organisms die without then being consumed, or when they defecat ...
PLATE TECTONICS SEAFLOOR SPREADING
... PLATE TECTONICS SEAFLOOR SPREADING MAKE A DIAGRAM TO IDENTIFY EVIDENCE FOR SEAFLOOR SPREADING. USE ARROWS TO SHOW THE DIRECTION OF SPREADING, AND INDICATE WHERE OLDER ROCK AND ...
... PLATE TECTONICS SEAFLOOR SPREADING MAKE A DIAGRAM TO IDENTIFY EVIDENCE FOR SEAFLOOR SPREADING. USE ARROWS TO SHOW THE DIRECTION OF SPREADING, AND INDICATE WHERE OLDER ROCK AND ...
theory of Plate Tectonics ppt
... and ocean trenches. The absence of deep-focus earthquakes along the oceanic ridge system was shown to be consistent with the new theory. ...
... and ocean trenches. The absence of deep-focus earthquakes along the oceanic ridge system was shown to be consistent with the new theory. ...
• Internal Structure of Earth and Plate Tectonics • Chapter 2 The
... of the continents across the Atlantic Ocean He also looked at shapes of both South America and Africa and theorized that the shapes of the two continents fit as if they once were one. In the late 1960’s this theory was finally accepted when seafloor spreading was discovered ...
... of the continents across the Atlantic Ocean He also looked at shapes of both South America and Africa and theorized that the shapes of the two continents fit as if they once were one. In the late 1960’s this theory was finally accepted when seafloor spreading was discovered ...
Power Point File 9
... and deep levels beneath subduction zones The earthquakes define a plane which begins at the trench and dips at about 45° beneath the arc This dipping plane of earthquake foci is called the Benioff Zone The Benioff Zone follows the upper part of the descending oceanic plate ...
... and deep levels beneath subduction zones The earthquakes define a plane which begins at the trench and dips at about 45° beneath the arc This dipping plane of earthquake foci is called the Benioff Zone The Benioff Zone follows the upper part of the descending oceanic plate ...
Hypoxia off the Pacific Northwest Coast
... when oxygen levels in seawater drop to levels that are too low to support most fishes, crabs and other marine life. Seawater is hypoxic if it the amount of oxygen is less than 1.4 milliliters of oxygen per liter (ml/l) of seawater. Hypoxic areas are also commonly termed “dead zones”, because most an ...
... when oxygen levels in seawater drop to levels that are too low to support most fishes, crabs and other marine life. Seawater is hypoxic if it the amount of oxygen is less than 1.4 milliliters of oxygen per liter (ml/l) of seawater. Hypoxic areas are also commonly termed “dead zones”, because most an ...
Crust-Mantle Connections in the Kermadec Arc
... the overlying crust. Where the crust is thin, melting occurs at relatively low pressures in the mantle wedge producing andesitic magmas. Where the crust is thick, melting pressures are higher and only basaltic magmas tend to be produced. The implications of this hypothesis are: (1) shallow mantle me ...
... the overlying crust. Where the crust is thin, melting occurs at relatively low pressures in the mantle wedge producing andesitic magmas. Where the crust is thick, melting pressures are higher and only basaltic magmas tend to be produced. The implications of this hypothesis are: (1) shallow mantle me ...
Criticisms of the subduction concept – can mobilism renounce to it?
... Dogma in the Earth Sciences. Stanford University Press, Stanford, California, pp.413. ...
... Dogma in the Earth Sciences. Stanford University Press, Stanford, California, pp.413. ...
Inside the Earth
... • Friction, when denser core material sinks • Decay of radioactive elements, mostly uranium and thorium according to physicists. ...
... • Friction, when denser core material sinks • Decay of radioactive elements, mostly uranium and thorium according to physicists. ...
The Restless Earth
... Trench and the lowest part of the Earth • Challenger Deep is the lowest elevation on the Earth’s crust at 11,035 metres deep. • You can fit Mount Everest in the Mariana Trench and there would still be over a mile of water left above it. ...
... Trench and the lowest part of the Earth • Challenger Deep is the lowest elevation on the Earth’s crust at 11,035 metres deep. • You can fit Mount Everest in the Mariana Trench and there would still be over a mile of water left above it. ...
Abyssal plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills). In addition to these elements, active oceanic basins (those that are associated with a moving plate tectonic boundary) also typically include an oceanic trench and a subduction zone.Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. The creation of the abyssal plain is the end result of spreading of the seafloor (plate tectonics) and melting of the lower oceanic crust. Magma rises from above the asthenosphere (a layer of the upper mantle) and as this basaltic material reaches the surface at mid-ocean ridges it forms new oceanic crust. This is constantly pulled sideways by spreading of the seafloor. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons down into deeper water. The remainder of the sediment is composed chiefly of pelagic sediments. Metallic nodules are common in some areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt, and copper. These nodules may provide a significant resource for future mining ventures.Owing in part to their vast size, abyssal plains are currently believed to be a major reservoir of biodiversity. The abyss also exerts significant influence upon ocean carbon cycling, dissolution of calcium carbonate, and atmospheric CO2 concentrations over timescales of 100–1000 years. The structure and function of abyssal ecosystems are strongly influenced by the rate of flux of food to the seafloor and the composition of the material that settles. Factors such as climate change, fishing practices, and ocean fertilization are expected to have a substantial effect on patterns of primary production in the euphotic zone. This will undoubtedly impact the flux of organic material to the abyss in a similar manner and thus have a profound effect on the structure, function and diversity of abyssal ecosystems.