Which of the following is part of the passive continental margin?
The Atlantic and Gulf coasts show the classic form of a passive continental margin: a low-lying coastal plain, broad continental shelf, then a steep continental slope, gentle continental rise, and flat abyssal plain. This topography is a consequence of the transition from thick continental to thin oceanic crust.
Which of the following is a feature of active continental margins?
Active margins are marked by earthquakes, volcanoes, and mountain belts. Unlike passive margins, they lack a continental rise and abyssal plain. Instead, the continental slope ends in an oceanic trench, and beyond the trench, the topography is hilly and irregular, often dotted with rugged volcanic seamounts.
Which ocean is both isothermal and Isopycnal?
The polar oceans are isopycnal ; The polar oceans are isothermal.
What are three major features of a passive continental margin?
The features comprising passive continental margins include the continental shelf (the flooded extension of the continent), the continental slope (has the steepest slope), and the continental rise.
What is the difference between an active continental margin and a passive continental margin?
Active continental margins tend to have narrow continental shelves. Passive continental margins are continental margins that are not tectonically active. These areas have flat lands and have a wide continental shelf, which is the submerged border of the continent.
How do the shelf and slope of an active continental margin differ from those of a passive margin?
How do the shelf and slope of an active continental margin differ from those of a passive continental margin? The slope of an active continental margin is significantly steeper because it is been compressed as subduction occurs (although accretionary prisms do develop.
Which of the following features is related to transform faults along mid ocean ridges?
Directly seaward of the continental shelf is a more steeply sloping region called the ________. Which of the following features is related to transform faults along mid-ocean ridges? With respect to mid-ocean ridges, transform faults are: perpendicular to the ridge axis.
Which of the following processes would decrease the amount of salinity in seawater?
Processes that decrease seawater salinity include evaporation and sea ice formation.
What happens to salinity in the Halocline?
halocline, vertical zone in the oceanic water column in which salinity changes rapidly with depth, located below the well-mixed, uniformly saline surface water layer.
How does hydrothermal metamorphism alter saltwater and the basaltic rocks that make up the seafloor?
How does hydrothermal metamorphism alter saltwater and the basaltic rocks that make up the seafloor? Hydrothermal metamorphism causes the minerals olivine and pyroxene in basalt to form new minerals, such as chlorite and serpentine.
What features accompany the development of mountains and basins in continental collisions?
Which features accompany the development of mountains and basins in continental collisions? An underthrust, as one continental plate is shoved beneath another. Faulted, folded, and cleaved rocks in high mountain belts. Sedimentary basins in front of the thrust sheets.
What happens at active margins?
An active continental margin is found on the leading edge of the continent where it is crashing into an oceanic plate. An excellent example is the west coast of South America. Active margins are commonly the sites of tectonic activity: earthquakes, volcanoes, mountain building, and the formation of new igneous rock.
How do the shelf and slope of an active continental margin differ from those of a passive margin quizlet?
How do the shelf and slope of an active continental margin differ from those of a passive continental margin? The slope of an active continental margin is significantly steeper because it is been compressed as subduction occurs (although accretionary prisms do develop.
What is the difference between an active continental margin and a passive continental margin quizlet?
An active continental margin is found on the leading edge of the continent where it is crashing into an oceanic plate. Passive continental margins are found along the remaining coastlines.
What geologic processes occur along mid-ocean ridges?
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth's tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
Which type of boundaries movement causing the formation of oceanic ridges?
When two plates are moving away from each other, we call this a divergent plate boundary. Along these boundaries, magma rises from deep within the Earth and erupts to form new crust on the lithosphere. Most divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges.
Which of the following increases the salinity of seawater?
Salinity of seawater is affected by evaporation, precipitation, ice formation, and ice melting. Evaporation increases the salinity of seawater because when seawater evaporates, the salts are left behind, thus increasing their concentration.
Which of the following processes would increase the density of seawater?
The density of water increases as the salinity increases. The density of seawater (salinity greater than 24.7) increases as temperature decreases at all temperatures above the freezing point. The density of seawater is increased by increasing pressure.
Does salinity increase or decrease in the halocline?
halocline, vertical zone in the oceanic water column in which salinity changes rapidly with depth, located below the well-mixed, uniformly saline surface water layer.
Why does salinity increase with depth?
At very great depth, salinity increases again because the water near the ocean bottom originates from polar regions where it sinks during the winter; freezing during the process increases its salinity.
What happens in hydrothermal metamorphism?
Hydrothermal metamorphism takes place when hot, volatile solutions percolate into and react with the protolith, or the original rock. The heat of the intrusive igneous body and the hot volatile fluids serves to catalyze metamorphic reactions in the host rock.
What process contributes to metamorphism of oceanic crust at a spreading ridge?
Almost all regions that experience metamorphism are being acted upon by plate-tectonic processes. Oceanic crustal rock can be metamorphosed near the spreading ridge where it was formed. Regional metamorphism takes place in areas where mountain ranges are forming, which are most common at convergent boundaries.
Which of the following are ways in which local mountains are generally created?
A local mountain is created if overthrust block is uplifted faster than it is eroded or it is composed of erosion-resistant rocks.
What is the name of the tectonic process that has created many of the mountains in Middle and South America?
orogeny Fold mountains are created where two or more of Earth's tectonic plates are pushed together. At these colliding, compressing boundaries, rocks and debris are warped and folded into rocky outcrops, hills, mountains, and entire mountain ranges. Fold mountains are created through a process called orogeny.
How do you tell if a margin is passive or active?
Active continental margins tend to have narrow continental shelves. Passive continental margins are continental margins that are not tectonically active. These areas have flat lands and have a wide continental shelf, which is the submerged border of the continent.
What is the difference between active and passive margin?
The west coast of the United States is an example of an active margin, where the coastline corresponds with the boundary between the Pacific and North America Plates. A passive continental margin occurs where the transition from land to sea is not associated with a plate boundary.
How do the continental shelf and slope of an active continental margin differ from those of a passive margin?
How do the shelf and slope of an active continental margin differ from those of a passive continental margin? The slope of an active continental margin is significantly steeper because it is been compressed as subduction occurs (although accretionary prisms do develop.
What process marks the start of the formation of a Mid Oceanic Ridge?
Mid-ocean ridges are created by the upwelling of basaltic lava and lateral rifting of ocean crust (Figure 6.12). They form a rift valley system that encircles the Earth along a total length of over 75,000 km (Figure 6.11).
Where does subduction occur?
Subduction zones are where the cold oceanic lithosphere sinks back into the mantle and is recycled. They are found at convergent plate boundaries, where the oceanic lithosphere of one plate converges with the less dense lithosphere of another plate.
What process occurs in divergent plate boundary?
A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries.