What is seismic hazard analysis?
What is seismic hazard analysis?
Based on geological and seismological studies, probabilistic seismic hazard analysis (PSHA) estimates the likelihood of a hazard, considering the uncertainties in magnitude and the location of earthquakes and their resulting ground motions that are likely to affect a particular site.
What is the difference between seismic hazard and seismic risk?
Seismic hazard is a natural phenomenon such as ground shaking, fault rupture, or soil liquefaction that is generated by an earthquake, whereas seismic risk is the probability that humans will incur loss or damage to their built environment if they are exposed to a seismic hazard. …
What is the outcome of a seismic hazard analysis?
Seismic hazard analysis involves the quantitative estimation of ground shaking hazards at a particular area. A critical part of seismic hazard analysis is the determination of Peak Ground Acceleration (PGA) and response acceleration (spectral acceleration) for an area/site.
How do we currently assess seismic hazards?
Seismic hazard maps integrate what scientists have learned about earthquake sources, crustal deformation, active faulting, and ground shaking to evaluate the earthquake hazards across the country.
What are the types of seismic hazard?
Earthquake Hazards
- Ground Shaking. If an earthquake generates a large enough shaking intensity, structures like buildings, bridges and dams can be severley damaged, and cliffs and sloping ground destabilised.
- Tsunami.
- Landslides and Rockfalls.
- Subsidence and Lateral Spreading.
- Liquefaction.
What is probabilistic seismic hazard analysis?
Probabilistic Seismic Hazard Analysis (PSHA) is a method used to estimate the level of ground motion with a specified probability of exceedance (Cornell, 1968; Reiter, 1990). The hazard estimates from all possible sources and at all distances are summed to create the hazard curves at each site.
What kinds of information are useful in assessing seismic risk?
According to the United States Geological Survey (USGS), there are three main factors that determine your seismic risk: the level of the seismic hazard, exposure to the hazard and how vulnerable that population and property is to the hazard.
How is seismic risk reduced?
In general, seismic risk can be reduced by mitigating seismic hazard and reducing vulnerability. Engineering can offer several technological remedies for most seismic hazards as well; although plate tectonic movements cannot be stopped, liquefaction or landslide potential can be mitigated by engineering measures.
Is a hurricane a seismic hazard?
Natural or environmental hazards include volcanic activity, seismic events (earthquakes) and tropical storms (hurricanes/typhoons/cyclones). All of these can therefore cause disruption to human systems, including death and injury, property and communication system damage and the disruption of economic activities.
What is the difference between deterministic and probabilistic seismic hazard analysis?
Probabilistic seismic hazard analysis has been practically unchallenged since its inception three decades ago. On the other hand, the deterministic procedure for earthquake hazard evaluation avoids the above defects by eliminating the falsely precise time element in the probabilistic estimation.
What is seismic hazard curve?
Seismic hazard is the hazard associated with potential earthquakes in a particular area, and a seismic hazard map shows the relative hazards in different areas. Past faults and earthquakes. The behavior of seismic waves as they travel through different parts of the U.S. crust.
What is probabilistic seismic hazard assessment?
When was the first probabilistic seismic hazard analysis published?
Probabilistic Seismic Hazard Analysis First addressed in 1968 by C. Allin Cornell in “Engineering Seismic Risk Analysis,” and article in the Bulletin of the Seismological Society (Vol. 58, No. 5, October). This is the reference that first described probabilistic seismic hazard analysis.
How is a hazard statement used in deterministic analysis?
In deterministic analysis, it is traditional to use the closest distance from a source to a site. It is very important to use attenuation relationships that are characteristic to the local geology. The resulting hazard statement is basically a scenario. FEMA 451B Topic 5a Notes Seismic Hazard Analysis 7
Who is the leader in earthquake risk reduction?
EERI is a leader in earthquake investigations and dissemination of earthquake risk reduction information. EERI has launched a landmark campaign to raise $4 million to guarantee a robust and dynamic Learning from Earthquakes program for years to come. Learn more
Are there seismic fault lines in Los Angeles?
It is known from deep drilling that a network of such faults exists in the Los Angeles area. The New Madrid seismic zone may be classified as a seismotectonic province – that is, we know that earthquakes have occurred there, but we are still unsure as to the source.