Assignment: Sources of Plate Motion Exploration
Introduction
Recall that scientists think gravity acting on the edges of tectonic plates is a factor in their movement. These effects are called ridge push and slab pull. You can model these effects with a chair and a bed.
Ridge push
If you sit on a chair and let gravity pull you down into a slouching position, you'll notice your legs move out away from the chair. When your upper body falls down, it pushes your legs out and away, just as the ridge of a tectonic plate falling down pushes on the other end of the plate. The other end of the plate moves out and away from the pushing part of the plate.
Slab pull
Lie on a bed facing down with your upper body hanging just a little over the edge. Slowly and
…show more content…
Describe what occurs at mid-ocean ridges.
A mid-ocean ridge is a mountain range under the water. It is formed due to plate tectonics. The shifting of the plates lifts up the floor of the ocean. When convection currents occur they raise the mantle that is located beneath the oceans crust and it creates magma where the two tectonic plates meet.
Study this map that shows the motion of the Earth's plates.
5. Find the Nazca plate and the South American plate. How are they different? Are they moving toward or away from each other?
The Nazca plate is an oceanic plate, while South American plate is continental. The Nazca is moving East towards the South American plate at a downward angle and converging. This process is called subduction, resulting in a lot of earthquakes and production of the Andes Mountains.
6. List the kinds of features you might expect to see near the edges of plates, like these two plates that are coming together.
Some features you may expect to see at the site where two plates converge, or a convergent boundary, would be mountains and volcanoes. It may even form a chain of volcanoes. Earthquakes are likely as well.
7. How is the Nazca plate moving in relation to the Pacific
This is evidence for continuous formation of new rock at the ridges. As more rock forms, older rock is pushed farther away from the ridge, producing symmetrical stripes to either side of the ridge. In the diagram to the right, the dark stripes represent ocean floor generated during "reversed" polar orientation and the lighter stripes represent the polar orientation we have today. Notice that the patterns on either side of the line representing the mid-oceanic ridge are mirror images of one another.
The Rocky Mountains were created by the Laramide orogeny, which began roughly 75 million years ago (Connor and Harrison 10). In the paleographic map below it shows the oceans wand where all the landmasses were during this time (DeMets). This can possible give one a better perspective as to what was going on, through out the rest of this process. Most mountains are created by plate boundaries. Either by continental collisions, or subduction zones at plate boundaries usually create mountains. The Rocky Mountains were not, though. These mountains were formed away from plate bo...
Once the Farallon plate disappeared, this brought the North American plate in direct contact with the Pacific plate. Initially the Pacific plate had being moving north, so when it first came into contact with the North American plate it didn’t subduct, but they rubbed against each other. This formed the San Andreas Fault
When the plates mash together on a convergent boundary, they can create an earthquake. A place with a convergent boundary is New Zealand. When the plates pull apart, a divergent boundary, they create a hole in the ocean that causes molten lava to rush up and it causes a volcano to form. A place with a divergent boundary is Iceland. With about 130 volcanoes all together, it has the most volcanoes of any country in the world and is on two tectonic plates. Santorini is currently in an area of earth where the African and Eurasian plate meet, and Atlantis disappeared with a rumble that could have come from a volcano or an
Island arcs form as oceanic plate subducts under oceanic plate. Volcanism is concentrated in an arc of volcanoes, generally approximately located above the leading edge of the subducting plate. A trench often forms where the slabs meet and subduction begins. On the non subducting slab a series of basins form, with a fore-arc basin nearest the subduction/trench, then the main arc, and a back-arc basin on the far side (Mitchell and Reading, 1971; Frisch, Meschede and Blakey, 2010).
Volcanism is a major part of the Galapagos and their formation. The island chain is positioned on the Nazca Plate, which is subducting beneath the South American Plate at a geologically rapid pace of 2.5 inches per year. In addition, this Nazca Plate is located directly on top of the Galapagos Hotspot. It is here that mantle plumes melt Earth’s crust, creating volcanoes as a product. The oldest island was first shaped by this ...
Tectonic Activity The continents of the world are all separated by different tectonic plates which when collide is called Tectonic Activity. There are different forms of tectonic activity and different processes and landforms, which are involved during and as a result of the collisions. As and when these collisions are going to take place we can't determine because current technology hasn't allowed us to dig as far into the earth to the point of pressures which causes the plates to collide. These pressures are believed to be eruptions of liquid magma deep inside the earth.
About 20 million years ago the last part of the Farallon sea floor plate subducted under the North American plate. This put the North American plate and the Pacific plate into contact, but unlike the Farallon sea floor plate, the Pacific plate sheared against the side of the North American plate. Because there was no plate subducting, the North American plate was in direct contact with the mantle (Tierney, 29). Heat from the mantle made the continental crust more ductile, which allowed the crust to extend and thin.
First you might need to know definition of tectonics. It is a theory in geology. The lithosphere of the Earth is divided into a small number of plates which float on and travel independently over the mantle and much of the Earth’s seismic activity occurs at the boundaries of these plates. That is the official definition of Plate tectonics. secondly, this plate covers many parts of continents. plate boundaries don’t go according to Continents boundaries, they make their own boundaries. The North American plat...
Source 4. A map of the Earth’s fault lines and plates with the direction of their movement.
Convection currents deep in the mantle of the earth, begin to well up towards the surface. As the pressure increases, it sets the crustal plates in motion. There are different kinds of mountains - Volcanic, Folded, Fault-block, and Dome mountains. Volcanic mountains are formed when magma comes up through cracks in the Earth’s crust and explodes out of lava and ash. The Hawaiian volcanoes, Mt. Hood, Mt. Etna, Vesuvius, and Mt. Saint Helens is an example of volcanic mountains.
The Pacific plate is moving northwest in relation to the North American plate, and it is believed that the total displacement along the fault since its formation more than 30 million years ago has been about 350 mi. Movement along the fault causes earthquakes; several thousand occur annually
Plate tectonics is the theory that landmasses on tectonic plates are in slow constant movement due to convection currents in the mantle. Plate tectonics, or the movements of plates above the lithosphere (the most upper layer of earth's crust) can cause divergent, convergent,and transform boundaries.A boundary the way two tectonic plates collide. is Continental plates are plates that the continents are formed on. Oceanic plates are plates that the ocean covers, and the oceans form on top of these plates. Convergent boundaries and divergent boundaries are ways that these oceanic and continental plates interact with each other. Landforms are formed at boundaries. The landforms formed at boundaries depends on the type of plates that collide, and
Understanding the plate tectonics theory is very important, especially when investigating natural disasters like earthquakes, and volcanic eruptions. It is also gives scientists the ability to understand how mountains were formed between two tectonic plates. There are three types of interactions between plate boundaries: convergent, divergent and transform. Looking back at the history of these three different interactions, earthquakes, like the one in Haiti, volcanic eruptions, like at Mount St. Helens, and the creation of mountain belts, like the Mid-Atlantic Oceanic ridge, gives information on future consequences of tectonic movement, and what can happen when the plates interact with each other.
The concurrent convective circulations in the mantle leads to some segments of the mantle moving on top of the outer core which is very hot and molten in nature. This kind of movement in different segments occurs as tectonic plates. These tectonic plates are basically seven on the earth surface as major ones, although, several small ones exist also. The plates motions are characterized by varying velocities, this variance results to sub sequential collision of two plates (leading to formation of a mountain in a convergent boundary), drift of two plates (leading to formation of rifts in a divergent boundary), or parallel movement in a transform boundary(Webcache 3).