What does elastic rebound theory say?
Elastic rebound is what happens to the crustal material on either side of a fault during an earthquake. The idea is that a fault is stuck until the strain accumulated in the rock on either side of the fault has overcome the friction making it stick.
What is elastic rebound?
In geology, the elastic-rebound theory is an explanation for how energy is released during an earthquake. Then they separate with a rupture along the fault; the sudden movement releases accumulated energy, and the rocks snap back almost to their original shape.
How are elastic rebound and elastic deformation different?
How are elastic rebound and elastic deformation different? Elastic deformation causes objects to bend, whereas rebound causes objects to return to their original shape. Elastic rebound refers to how the slippage along a fault (i.e., earthquake) allows the deformed rock to regain its original shape in a new location.
When elastic strain takes place the rock can rebound to its original shape?
Figure 12.3 Elastic deformation, rupture, and elastic rebound. Top: Stress applied to a rock causes it to deform by stretching. When the stress becomes too much for the rock, it ruptures, forming a fault. The rock snaps back to its original shape in a process called elastic rebound.
What is fault creep?
In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. An aseismic creep exists along the Calaveras fault in Hollister, California.
Is there a chance where a particular rock that is deformed has a chance to go back to its original shape?
Rock that has undergone only elastic strain will go back to its original shape if the stress is released. A rock that has undergone ductile strain will remain deformed even if the stress stops. Another term for ductile strain is plastic deformation. Fracture is also called rupture.
How will compressional force change a rock body?
How will compressional force change a rock body? Shorten and thicken the rock.
What is the deformation caused by stress?
There are three types of stress: compression, tension, and shear. Stress can cause strain, if it is sufficient to overcome the strength of the object that is under stress. Strain is a change in shape or size resulting from applied forces (deformation). Rocks only strain when placed under stress./span>
What can cause rocks to thicken or fold?
When rocks deform in a ductile manner, instead of fracturing to form faults or joints, they may bend or fold, and the resulting structures are called folds. Folds result from compressional stresses or shear stresses acting over considerable time./span>
What are two ways rocks permanently deform?
Rocks deform permanently in two ways: brittle deformation and ductile deformation.
What are the 4 factors that affect rock strength?
The principal factors controlling the strength of solid rocks are: I) mineral composition, structure and texture; 2) bedding, jointing and anisotropy; 3) water content; 4) state of stress in the rock mass.
What causes rock to deform?
Rocks Are Stressed Stress causes rocks to deform, meaning the rocks change size or shape. There are different kinds of stress that rocks experience, and these determine how the rocks deform. Tensional stress is when rock is stretched apart. Compressional stress is when rock is pressed together./span>
What are the three components of deformation?
The total amount of deformation between two converging bodies is described by the three components of the displacement field: translation, rotation, and strain.
What are the three types of faults?
Different types of faults include: normal (extensional) faults; reverse or thrust (compressional) faults; and strike-slip (shearing) faults.
What do you call the deformation in rock layers where there is a change in shape without breaking?
4. Fig. 10.7c: At higher confining pressures, a similarly directed external force will cause the deeply buried rock to actually flow and deform without fracturing. This is known as ductile deformation and the rock is said to behave plastically.
What will possibly happen when rocks bend without breaking?
If rocks tend to bend without breaking, they are said to be ductile. If a rock bends but is able to return to its original position when the stress is released, it is said to undergo elastic behavior. Earthquakes and faults occur in the shallow crust, where rocks are relatively cold and therefore brittle.
Is a simple bend in the rock layers so that they are no longer horizontal?
A monocline is a simple bend in the rock layers so that they are no longer horizontal. Anticlines are folded rocks that arch upward and dip away from the center of the fold.
Which type of strain can cause a rock to bend without breaking?
What is tensional stress?
Tensional stress is the stress that tends to pull something apart. It is the stress component perpendicular to a given surface, such as a fault plane, that results from forces applied perpendicular to the surface or from remote forces transmitted through the surrounding rock.
What are the 3 main types of stress the earth crust is exposed to?
Stress is the force applied to a rock and may cause deformation. The three main types of stress are typical of the three types of plate boundaries: compression at convergent boundaries, tension at divergent boundaries, and shear at transform boundaries.
What is the difference between a joint and a fault?
Joints and faults are types of fractures. A joint is a fracture along which no movement has taken place, usually caused by tensional forces. A fault is a fracture or break in the rock along which movement has taken place.
How do you recognize faults in the field?
To correctly identify a fault, you must first figure out which block is the footwall and which is the hanging wall. Then you determine the relative motion between the hanging wall and footwall. Every fault tilted from the vertical has a hanging wall and footwall.
Where do most earthquakes happen?
Where do earthquakes occur?
- The world’s greatest earthquake belt, the circum-Pacific seismic belt, is found along the rim of the Pacific Ocean, where about 81 percent of our planet’s largest earthquakes occur.
- The Alpide earthquake belt extends from Java to Sumatra through the Himalayas, the Mediterranean, and out into the Atlantic.
How are faults formed?
A fault is formed in the Earth’s crust as a brittle response to stress. Generally, the movement of the tectonic plates provides the stress, and rocks at the surface break in response to this. Faults have no particular length scale.
What are the 4 types of faults?
There are four types of faulting — normal, reverse, strike-slip, and oblique. A normal fault is one in which the rocks above the fault plane, or hanging wall, move down relative to the rocks below the fault plane, or footwall.
Why do normal faults occur?
Normal faults form when the hanging wall drops down in relation to the footwall. Extensional forces, those that pull the plates apart, and gravity are the forces that create normal faults. They are most common at divergent boundaries./span>
Do normal faults cause earthquakes?
Earthquakes occur on faults – strike-slip earthquakes occur on strike-slip faults, normal earthquakes occur on normal faults, and thrust earthquakes occur on thrust or reverse faults. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the other.
What type of fault is the most dangerous?
SAN FRANCISCO (KGO) — While the San Andreas fault gets much of the attention after the devastating 1906 and 1989 quakes, it’s the Hayward fault, which runs along the East Bay, that quake experts consider the most dangerous fault in America./span>
Where can reverse faults be found?
Reverse faults, also called thrust faults, slide one block of crust on top of another. These faults are commonly found in collisions zones, where tectonic plates push up mountain ranges such as the Himalayas and the Rocky Mountains. All faults are related to the movement of Earth’s tectonic plates./span>
Why is it bad to drill on a fault line?
It will be like drilling into a volcano. Removing the oil from the Santa Barbara coastline will trigger larger earthquakes and tsunamis. If we drill into this fault zone and remove the oil from this gigantic 3000 mile fault zone crossing the Pacific Ocean, we will make two changes that are not at all good./span>