What is seismic gap?
A seismic gap is a section of a fault that has produced earthquakes in the past but is now quiet.
What is a seismic gap quizlet?
Seismic gap. A seismic gap is a segment of an active fault known to produce significant earthquakes, that has not slipped in an unusually long time when compared with other segments along the same structure.
What are seismic gaps caused by?
The absence of large earthquakes in one region along a tectonic front is called a seismic gap. Such gaps are tectonic time bombs waiting to go off in a major earthquake. At most other locations along the Cocos subduction zone the tectonic stresses have been release by earthquakes over the last century.
How would you describe a seismic wave?
A seismic wave is an elastic wave generated by an impulse such as an earthquake or an explosion. Seismic waves may travel either along or near the earth's surface (Rayleigh and Love waves) or through the earth's interior (P and S waves).
How is seismic gap calculated?
CODAL RECOMMENDATIONS FOR SEISMIC SEPARATION GAP When the floor levels of two adjacent units of same building or buildings are at the same floor levels, the separation distance shall be calculated as (R1∆1 + R2∆2), where R1 and ∆1 correspond to building 1 and R2 and ∆2 corresponds to building 2.
What do some scientists think will occur at seismic gaps?
Some scientists think that seismic gaps are likely locations of future earthquakes. Several seismic gaps that exist along the San Andreas Fault zone may be sites of major earthquakes in the future.
What is a seismic gap how is it used in earthquake prediction?
Seismic gaps – A seismic gap is a zone along a tectonically active area where no earthquakes have occurred recently, but it is known that elastic strain is building in the rocks. If a seismic gap can be identified, then it might be an area expected to have a large earthquake in the near future.
How is the seismic risk of an area estimated?
Seismic risk is often determined using a seismic modeling computer programs which uses the seismic hazard inputs and combines them with the known susceptibilities of structures and facilities, such as buildings, bridges, electrical power switching stations, etc.
Which of the following are true for seismic waves?
The following are true for seismic waves: Body waves travel within and through Earth.
What is seismic geologic hazard zone?
A Seismic Hazard Zone is a regulatory zone that encompasses areas prone to liquefaction (failure of water-saturated soil) and earthquake-induced landslides. Liquefaction occurs when loose, water-saturated sediments lose strength and fail during strong ground shaking.
Does liquefaction cause earthquake?
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
What makes strong earthquakes more likely to happen in seismic gaps?
A part of an active fault that hasn't had a strong earthquake in a long time is called a seismic gap. The gap hypothesis says that if an active fault hasn't had a strong earthquake in a long time, it is likely to have one soon. In other words, it says that strong earthquakes are more likely to happen in seismic gaps.
When stress along a seismic gap builds up it causes?
When enough stress builds up, movement occurs along one or more of the individual faults in the fault zone and some- times causes major earthquakes.
What data do scientists need to determine whether a seismic gap may exist along a fault?
Seismologists can determine the point on a fault where the slippage began the area (length and depth) of the fault that slipped the amount of slippage or fault throw (how far the crust moved) and the time it took for the slippage to occur.
What is seismic risk zone?
A seismic hazard zone describes an area with a particular level of hazard due to earthquakes. Typically, a high seismic hazard zone is nearest a seismic zone where there are more earthquakes, and a lower seismic hazard zone is farther away from a seismic zone.
What is seismic risk assessment?
Through seismic risk assessments, engineers evaluate how a structure would perform during an earthquake to estimate the possible financial impact, or probable maximum loss (PML), that would occur after a major event.
What is not true about seismic waves quizlet?
What is NOT true about seismic waves? The material within the wave moves long distances along with the wave. Which of the following would NOT be a good idea in an area that has a high risk for earthquakes? Which of the following places did NOT experience a major earthquake?
What can seismic waves tell us?
Seismic waves tell us that the Earth's interior consists of a series of concentric shells, with a thin outer crust, a mantle, a liquid outer core, and a solid inner core. P waves, meaning primary waves, travel fastest and thus arrive first at seismic stations. The S, or secondary, waves arrive after the P waves.
What is seismic zone2?
Seismic Zone II: Zone II is classified as the low-damage risk zone. This is the least seismically active zone, meaning the areas that fall under these zones in India have a low chance of having an earthquake. Zone II covers earthquake-prone areas, which are 41% of India.
How are seismic zones classified?
According to Modified Mercalli scale, the seismic zone intensity are classified as zone II (low intensity zone), zone III (moderate intensity zone), zone IV (severe intensity zone) and zone V (very severe intensity zone).
What is liquefaction geology quizlet?
liquefaction. a phenomenon that happens in areas where unconsolidated (loosely arranged) materials are saturated with water. The earthquake vibrations can turn stable soil into a mobile fluid. rearrangement of grains, increase in water pressure, water squeezes out.
What liquefaction means?
of making or becoming liquid Definition of liquefaction 1 : the process of making or becoming liquid. 2 : the state of being liquid. 3 : conversion of soil into a fluidlike mass during an earthquake or other seismic event.
Why are earthquakes less common along seismic gaps group of answer choices?
Why are earthquakes less common in seismic gaps? The rock on either side of the fault in a seismic gap is locked and stores rather than releases energy.
How is a seismic gap recognized?
Seismic gaps – A seismic gap is a zone along a tectonically active area where no earthquakes have occurred recently, but it is known that elastic strain is building in the rocks. If a seismic gap can be identified, then it might be an area expected to have a large earthquake in the near future.
What is meant by seismic zone in engineering geology?
In seismology, a seismic zone or seismic belt is an area of seismicity potentially sharing a common cause. It may also be a region on a map for which a common areal rate of seismicity is assumed for the purpose of calculating probabilistic ground motions.
What is considered when determining the seismic risk of an area?
Thus, seismic risk is determined by the likelihood that an earthquake could negatively impact the people and property where such a hazard occurs. For example, consider two areas that are equally prone to earthquakes.
Which of the following are true for seismic waves quizlet?
The following are true for seismic waves: Body waves travel within and through Earth.
What is not true of seismic waves?
What is NOT true about seismic waves? The material within the wave moves long distances along with the wave. Which of the following would NOT be a good idea in an area that has a high risk for earthquakes? Which of the following places did NOT experience a major earthquake?
What type of wave is a seismic wave?
Types of Seismic Waves The two main types of waves are body waves and surface waves. Body waves can travel through the Earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes send out seismic energy as both body and surface waves.
What is seismic zone4?
Zone-IV includes the remaining parts of Jammu and Kashmir and Himachal Pradesh. Delhi-NCR region, Sikkim, northern parts of Uttar Pradesh, Bihar and West Bengal, parts of Gujarat and small portions of Maharashtra near the west coast and Rajasthan also fall in this zone.