Abyssal plains and abyssal hills cover about 25% of the surface of Earth. What are the characteristics of each of these features?
Abyssal hills and plains cover about 25% of the surface of the Earth. Abyssal plains are extraordinarily flat expanses of the ocean floor consisting of layers of sediment. Most of the sediment layers originated from shallow water or continental margins, and in some areas can be over 1000 meters thick. Abyssal plains lie between 3,700 and 5,500 meters beneath the surface, and are located between the continental margins and oceanic ridges. In some areas, the sediment layer may not be thick enough to cover the basaltic oceanic floor, especially near the edges of the ridges. In these areas, small abyssal hills are formed as sediment covers extinct volcanoes that once spewed molten rock. Abyssal hills are usually only about 200 meters high and are most commonly associated with seafloor spreading areas. They form when newly formed crust moves away from the center of a ridge, stretches, and cracks. Some blocks of the crust drop to form valleys, and others remain higher as hills.
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Which was NOT a reason for the present economic crisis in Europe?
A) the insistence of wealthier EU nations demanding poorer ones engage in fiscal austerity, which had the effect of unemployment in the poorer nations (and thus less tax revenue) B) overspending by governments in weaker EU nations C) the lingering effects of the 2008 global financial crisis D) cheap credit available to weaker EU economies (such as Greece) E) widespread Soviet interference in eastern Europe's economies
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a. heavy rain b. heavy snow c. hail d. thunderstorms e. light rain or snow
What is the linear distance from the 1400-ft elevation contour in Trail Canyon to the 200-ft contour? What is the relief between these two points?
What will be an ideal response?
Why is the early rock record of the Precambrian rocks more difficult to interpret than the rock
record of the Phanerozoic Eon? What will be an ideal response?