What is a transform boundary?
Places where plates slide past each other are called transform boundaries. Since the plates on either side of a transform boundary are merely sliding past each other and not tearing or crunching each other, transform boundaries lack the spectacular features found at convergent and divergent boundaries. Instead, transform boundaries are marked in some places by linear valleys along the boundary where rock has been ground up by the sliding. In other places, transform boundaries are marked by features like stream beds that have been split in half and the two halves have moved in opposite directions. Perhaps the most famous transform boundary in the world is the San Andreas fault. The slice of California to the west of the fault is slowly moving north relative to the rest of California. Since motion along the fault is sideways and not vertical, Los Angeles will not crack off and fall into the ocean as popularly thought, but it will simply creep towards San Francisco at about 6 centimeters per year. In about ten million years, the two cities will be side by side! Although transform boundaries are not marked by spectacular surface features, their sliding motion causes lots of earthquakes. The strongest and most famous earthquake along the San Andreas fault hit San Francisco in 1906. Many buildings were shaken to pieces by the quake, and much of the rest of the city was destroyed by the fires that followed. More than 600 people died as a result of the quake and fires. Recent large quakes along the San Andreas include the Imperial Valley quake in 1940 and the Loma Prieta quake in 1989.
Transform boundaries, what do they form?
Transform boundaries are boundaries where two tectonic plates are sliding next to one another. They form the geologic structures known as faults. A good example of a transform boundary is the San Andreas fault, which is formed by the movement of the Pacific plate next to the North American plate.
Why are there no volcanic activities in transform boundaries?
theres no activity because all that is happening is that the plates are rubbing against eachother. they are not separating or coming together. when plates separate is when you have volcanic activity.
What are transform plate boundaries?
Transform plate boundaries, also known as conservative plate boundaries, are where 2 plates are sliding past each other. This is the only type of plate boundary which does not produce volcanoes or mountains.Expressed by steep, linear ridges and valleys they are mainly found on the ocean floor at divergent boundaries where they offset mid ocean ridges (such as the Mid Atlantic Ridge) and enable the ocean to spread at different rates. These are known as Faults.Faults are caused by cracks in rock caused by the movement of the plates that compress or stretch a section of Earth’s crust. As these plates slide under or slide past one another, they put huge stress on the rock along the edges of each plate. A new fault forms when the stress on the rock is great enough to cause a fracture, and one wall in the fracture moves relative to the other.Transform faults move differently from normal strike-slip faults. Instead of the ridges moving away from each other, as they do in other strike-slip faults, transform-fault ridges remain in the same, fixed locations, and where they are at mid ocean ridges, the new ocean seafloor created at the ridges is pushed away from the ridge.The Mid Atlantic Ridge- a divergent boundary with transform faultsIn some places, Transform Faults are marked by linear valleys along the boundary where rock has been ground up by the sliding. In other places, they are marked by features like stream beds, fences etc that have been split in half and the two halves have moved in opposite directions.Deformation at a Transform boundaryHowever, this is not a smooth passing such as it would be if 2 cars were passing each other.The San Andreas Transform Fault- the biggest in the world.The fault is always parallel to the direction of movement of the plates. The most famous Transform Fault is the San Andreas Fault in California. (shown above) where the western half of California is moving north because it is part of the Pacific Plate, and the eastern half of California is moving southbecause it is part of the North American Plate.Because there is no gap between the plates, they frequently stick and strain builds up in the rocks. This eventually gets to a point where the rocks can take no more and they snap at the point where the strain is greatest. That causes an earthquake. The great San Francisco earthquake of 1906 was caused by movement of the San Andreas Fault.
Transform boundaries change, or transform, the relative movement of the plates involved.?
depending on whether it is a right or left lateral transform boundary, it will either move sinistrily or dexterally.
Why are volcanoes NOT found at transform boundaries?
Transform boundaries cause decreases in temperature that exactly offset increases in pressure of the mantle. Transform boundaries cause increases in temperature that exactly offset decreases in pressure of the mantle. Transform boundaries cause changes to the pressure, temperature, or composition of the mantle. Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle.
Why are there transform boundaries along the length of the mid-oceanic ridge?
Because the driving force behind plate tectonics is not magma upwelling at the mid-ocean ridges.The driving force for plate tectonics is subduction - which is the old, cold, dense crust and lithosphere sinking back into the mantle. As it sinks down, it stretches the crust and as the crust thins the pressure drops resulting in partial melting of the mantle and subsequent volcanism (ie, the mid-ocean ridge volcanism).But not all subduction zones move at the same rate, and part of a subduction zone can get ‘locked’ so that it moves at a slower rate than other parts (look at the Tonga-Kermadec arc on the map below and note that as you go further south the subduction rate slows down).When you have one part moving faster and one slower, something has to give. That’s one of the causes for the transform faults.Another cause is due to the Earth being an oblate spheroid and that the plates are not just pulling apart, but the individual plates are also rotating relative to each other. If it were a simple pull apart, then there would be no need for transform faults, but because it is not simple, the movement has to be accommodated through appropriate structures - aka, the transform faults.
What geologic events occur at a transform boundary?
A transform boundary is where the plates are passing each other like if you press your palms together but try sliding them at the same time. If you try that you will notice that the motion occurs in jumps rather than smoothly (pressing palms together as they slide). The plates move in jumps as well when the stress builds up past the bonds or friction holding the plates together. That is an earthquake when it happens at the plate boundary. Other things can happen geologically as well as you might imagine, for instance normal faulting from pulling and even thrust faulting from compression effects because the plates aren’t completely smooth and sometimes get stuck in places. Big rocks can be pulled apart and broken or crushed together and heated from the friction. Within the transform fault will often be smaller strike slip faulting and is part of this, too. Generally though, earthquakes will be the most common answer.
Why are earthquakes common along transform fault boundary?
Earthquakes are common along all boundaries, transform is no more likely than convergent or divergent.Plate tectonics Some fault zones are more active than others, which is a function of the convergence rate. The faster two plates are converging the higher the rate of stress build up in the crust and the more frequent the earthquakes are to relieve that stress.