Document
... under it is still lighter than the mantle it has entered. •It rises up through weaknesses in the crust and reaches the surface explosively as a volcano ...
... under it is still lighter than the mantle it has entered. •It rises up through weaknesses in the crust and reaches the surface explosively as a volcano ...
The Birth of a Theory
... One of the main objections to the continental drift hypothesis was the inability of its supporters to provide an acceptable mechanism for the movement of continents. The theory of plate tectonics, a far more encompassing theory than continental drift, holds that Earth's rigid outer shell, called the ...
... One of the main objections to the continental drift hypothesis was the inability of its supporters to provide an acceptable mechanism for the movement of continents. The theory of plate tectonics, a far more encompassing theory than continental drift, holds that Earth's rigid outer shell, called the ...
South Pacific Ocean - Alvarado High School
... warmer. However, because the ratio of land to sea area is greater in the North Pacific, the cumulative amount of cold deep water is less. In other words, the average temperature of waters in the North Pacific is warmer because there are more coastal areas. Also, the deep currents coming up from Anta ...
... warmer. However, because the ratio of land to sea area is greater in the North Pacific, the cumulative amount of cold deep water is less. In other words, the average temperature of waters in the North Pacific is warmer because there are more coastal areas. Also, the deep currents coming up from Anta ...
Plate Tectonics PowerPoint
... 1. The ages of the rocks that make up the seafloor vary in different places. Near the mid ocean ridge, with new crust, the sediment is thinner. Farther out, the sediment is thicker on the older crust. 2. The thickness of ocean-floor sediment was, in general, much less than expected and that the thic ...
... 1. The ages of the rocks that make up the seafloor vary in different places. Near the mid ocean ridge, with new crust, the sediment is thinner. Farther out, the sediment is thicker on the older crust. 2. The thickness of ocean-floor sediment was, in general, much less than expected and that the thic ...
of Earthquakes
... The mantle is a thick shell of dense rock that separates the crust above from the core below Seismic wave studies indicate the mantle, like the crust, is made of solid rock with only isolated pockets of magma Higher seismic wave velocity (8 km/sec) of mantle vs. ...
... The mantle is a thick shell of dense rock that separates the crust above from the core below Seismic wave studies indicate the mantle, like the crust, is made of solid rock with only isolated pockets of magma Higher seismic wave velocity (8 km/sec) of mantle vs. ...
3 How does the movement of lithospheric plates cause major events
... 42. At convergent boundaries oceanic plates will go under continental plates because oceanic crust is more dense than continental crust. 43. Oceanic-continental convergent boundaries can form mountains. 44. At convergent plate boundaries known as subduction zones, a trench and deep earthquakes mark ...
... 42. At convergent boundaries oceanic plates will go under continental plates because oceanic crust is more dense than continental crust. 43. Oceanic-continental convergent boundaries can form mountains. 44. At convergent plate boundaries known as subduction zones, a trench and deep earthquakes mark ...
File - Mariana Gil
... Subduction Zones and Volcanoes At some convergent boundaries, an oceanic plate collides with a continental plate. Oceanic crust tends to be denser and thinner than continental crust, so the denser oceanic crust gets bent and pulled under, or subducted, beneath the lighter and thicker continental cru ...
... Subduction Zones and Volcanoes At some convergent boundaries, an oceanic plate collides with a continental plate. Oceanic crust tends to be denser and thinner than continental crust, so the denser oceanic crust gets bent and pulled under, or subducted, beneath the lighter and thicker continental cru ...
... We selected this section of the MidAtlantic Ridge because it has been studied intensively over many years, beginning with the famous FAMOUS (French-American Mid-Ocean Undersea Study) Project in 1974—the first expedition using human-occupied vehicles to explore a mid-ocean ridge—and more recently by ...
Plate Tectonics
... Seafloor Spreading: Evidence • Magnetic reversals & the seafloorMagnetic surveys of ocean floor revealed alternating bands of high and low intensity magnetism – often called “zebra stripes” – The bands correspond to times of normal and reverse polarity. – The bands are parallel to mid-oceans ridge ...
... Seafloor Spreading: Evidence • Magnetic reversals & the seafloorMagnetic surveys of ocean floor revealed alternating bands of high and low intensity magnetism – often called “zebra stripes” – The bands correspond to times of normal and reverse polarity. – The bands are parallel to mid-oceans ridge ...
Earth Space Science
... led to a theory of plate tectonics, and when were these discoveries made? In 1915, Alfred Wegener wrote a book with about a theory called continental drift, stating that continents moved or drifted around the ocean. Continental drift led to the theory of plate tectonics in the 1960s ...
... led to a theory of plate tectonics, and when were these discoveries made? In 1915, Alfred Wegener wrote a book with about a theory called continental drift, stating that continents moved or drifted around the ocean. Continental drift led to the theory of plate tectonics in the 1960s ...
Earth Science for Struggling Students Book 1: Inside the Earth
... live. The mantle is made up of three parts: The lithosphere, the upper most part of the mantle, is also part of the crust. The middle mantle, called the asthenosphere, is semi-solid and can bend like hot plastic. In this region you can find the convection currents. Here heat is distributed. The heat ...
... live. The mantle is made up of three parts: The lithosphere, the upper most part of the mantle, is also part of the crust. The middle mantle, called the asthenosphere, is semi-solid and can bend like hot plastic. In this region you can find the convection currents. Here heat is distributed. The heat ...
Plate Tectonics PPT #1
... there were glaciers in southern Africa. Today southern Africa has tropical climates. ...
... there were glaciers in southern Africa. Today southern Africa has tropical climates. ...
Plate Tectonics ppt
... meet at the edge of the present-day African continent will separate completely, allowing the Indian Ocean to flood the area and making the easternmost corner of Africa (the Horn of Africa) a large island. ...
... meet at the edge of the present-day African continent will separate completely, allowing the Indian Ocean to flood the area and making the easternmost corner of Africa (the Horn of Africa) a large island. ...
Edible Tectonics
... Also called spreading centers because they are fractures in the lithosphere where the plates are moving apart, as in the Mid-Ocean Ridge system or rift valleys like the one running through eastern Africa. As the plates separate, pressure on the mantle directly below decreases. The decrease in pressu ...
... Also called spreading centers because they are fractures in the lithosphere where the plates are moving apart, as in the Mid-Ocean Ridge system or rift valleys like the one running through eastern Africa. As the plates separate, pressure on the mantle directly below decreases. The decrease in pressu ...
Continental Arcs
... magmas • Heat from these magmas melt the lower crust • Residual melts may rise • Exsolved volatiles also facilitate rise ...
... magmas • Heat from these magmas melt the lower crust • Residual melts may rise • Exsolved volatiles also facilitate rise ...
QUIZ
... a. Briefly explain using specific detail or examples how the following observations were used to support Wegener’s hypothesis of continental drift. (choose 3) fit of the continents paleoclimate fossil record glacial evidence mountain ranges and rock types b. What important explanation was missing fr ...
... a. Briefly explain using specific detail or examples how the following observations were used to support Wegener’s hypothesis of continental drift. (choose 3) fit of the continents paleoclimate fossil record glacial evidence mountain ranges and rock types b. What important explanation was missing fr ...
A density model of the Andean subduction zone
... imaged by seismic data. Thus, the model has a very simple conventional layered crust. The bottom of the sedimentary basin is estimated from density modeling. 5) Beginning in the Oligocene, the crust beneath the Eastern Cordillera and Subandean ranges has been thickening due to underthrusting of the ...
... imaged by seismic data. Thus, the model has a very simple conventional layered crust. The bottom of the sedimentary basin is estimated from density modeling. 5) Beginning in the Oligocene, the crust beneath the Eastern Cordillera and Subandean ranges has been thickening due to underthrusting of the ...
ISN- Insert Plate Tectonics for Cornell Notes
... Plates move apart, or diverge, from each other at a divergent boundary. Most divergent boundaries occur along the mid-ocean ridges, where new crust is added during sea-floor spreading. Where pieces of Earth’s crust diverge on land, a deep valley called a rift valley forms where the crust is slowly p ...
... Plates move apart, or diverge, from each other at a divergent boundary. Most divergent boundaries occur along the mid-ocean ridges, where new crust is added during sea-floor spreading. Where pieces of Earth’s crust diverge on land, a deep valley called a rift valley forms where the crust is slowly p ...
Data Do Not Speak - The Story Behind The Science
... To resolve this problem, Runcorn studied rocks in North America. The data he collected could be interpreted to mean that the pole had moved. However, the path of the pole based on rocks from North America was different than the path derived from rocks in Europe. The 'mobilist' view that the continen ...
... To resolve this problem, Runcorn studied rocks in North America. The data he collected could be interpreted to mean that the pole had moved. However, the path of the pole based on rocks from North America was different than the path derived from rocks in Europe. The 'mobilist' view that the continen ...
Study Guide
... - Spreading rates can now be measured directly by satellite using the Global Positioning System (GPS) discussed in chapter 1. - Some forty or so areas of spatially fixed, long-term volcanic activity have been identified on Earth, and are called hot spots (fig. 3.34). - Hot spot magmas change composi ...
... - Spreading rates can now be measured directly by satellite using the Global Positioning System (GPS) discussed in chapter 1. - Some forty or so areas of spatially fixed, long-term volcanic activity have been identified on Earth, and are called hot spots (fig. 3.34). - Hot spot magmas change composi ...
Lecture 4:the observed mean circulation
... •The strong currents on the western side of ocean basins transport warm water from low to high latitude in the subtropics and cool water from high to low latitudes in the subpolar regions. ...
... •The strong currents on the western side of ocean basins transport warm water from low to high latitude in the subtropics and cool water from high to low latitudes in the subpolar regions. ...
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.