Ground shaking is the primary cause of earthquake damage to man-made structures. Many factors influence the strength of earthquake shaking at a site including the earthquake's magnitude, the site's proximity to the fault, the local geology, and the soil type.

More than 250 structures throughout the United States have been outfitted with seismic sensors by the USGS National Strong Motion Project (NSMP) to improve the overall understanding of earthquakes and their effects on the built environment.

The instrumentation and monitoring of structures by NSMP is only one part of USGS efforts to protect people’s lives and property from earthquake hazards in all of the Nation’s seismically active regions.

Learn more: Multidisciplinary Center for Earthquake Engineering Research

## Related Content

#### What is the USGS doing to mitigate and respond to earthquake hazards?

The U.S. Geological Survey performs the following functions related to earthquake hazard mitigation:Receives, analyzes, maintains, and distributes data on earthquake activity worldwide. Satellites link our National Earthquake Information Center in Golden, Colorado to a network of seismograph stations. These stations, located throughout the world, are maintained by the U.S. Geological Survey, State...

#### What is the USGS doing to mitigate and respond to earthquake hazards?

The U.S. Geological Survey performs the following functions related to earthquake hazard mitigation:Receives, analyzes, maintains, and distributes data on earthquake activity worldwide. Satellites link our National Earthquake Information Center in Golden, Colorado to a network of seismograph stations. These stations, located throughout the world, are maintained by the U.S. Geological Survey, State...

#### How are engineers working to make roads and buildings safer?

Earthquake engineers are working to make roads and buildings safer in the event of a major earthquakes. This includes both improving the design of new buildings and bridges as well as strengthening older units to incorporate the latest advances in seismic and structural engineering. The Federal Emergency Management Agency plays a central role in funding research and development for the purpose of...

#### How are engineers working to make roads and buildings safer?

Earthquake engineers are working to make roads and buildings safer in the event of a major earthquakes. This includes both improving the design of new buildings and bridges as well as strengthening older units to incorporate the latest advances in seismic and structural engineering. The Federal Emergency Management Agency plays a central role in funding research and development for the purpose of...

#### How do I get earthquake hazard maps for locations outside of the U.S.?

We know of no current "zone" designations for sites outside of the United States. For locations outside the United States for which seismic design is required for military facilities, there exists a standard based on probabilistic spectral ordinates in the manner of the International Building Code and are declared to reflect the 2015 version of that code. These spectral ordinates can be found in...

#### How do I get earthquake hazard maps for locations outside of the U.S.?

We know of no current "zone" designations for sites outside of the United States. For locations outside the United States for which seismic design is required for military facilities, there exists a standard based on probabilistic spectral ordinates in the manner of the International Building Code and are declared to reflect the 2015 version of that code. These spectral ordinates can be found in...

#### Can the National Seismic Hazard Maps be used as an earthquake forecast tool for the near future?

Not really. The USGS Seismic Hazard Maps website and the Unified Hazard Tool (for building custom maps) are designed to display the probability of different events that might occur in a several-year to several-decade period. The model bases all probability estimates on the average rate of earthquakes over long periods of time.As you shorten the time window, you should expect greater and greater...

#### Can the National Seismic Hazard Maps be used as an earthquake forecast tool for the near future?

Not really. The USGS Seismic Hazard Maps website and the Unified Hazard Tool (for building custom maps) are designed to display the probability of different events that might occur in a several-year to several-decade period. The model bases all probability estimates on the average rate of earthquakes over long periods of time.As you shorten the time window, you should expect greater and greater...

#### What is the difference between earthquake early warning, earthquake forecasts, earthquake probabilities, and earthquake prediction?

The USGS uses these four terms to refer to four different things.Early warning is a notification that is issued after an earthquake starts. Probabilities and forecasts are comparable to climate probabilities and weather forecasts, while predictions are more like statements of when, where, and how large, which is not yet possible for earthquakes.Here are more detailed descriptions of each...

#### What is the difference between earthquake early warning, earthquake forecasts, earthquake probabilities, and earthquake prediction?

The USGS uses these four terms to refer to four different things.Early warning is a notification that is issued after an earthquake starts. Probabilities and forecasts are comparable to climate probabilities and weather forecasts, while predictions are more like statements of when, where, and how large, which is not yet possible for earthquakes.Here are more detailed descriptions of each...

#### What is the probability that an earthquake is a foreshock to a larger earthquake?

Worldwide the probability that an earthquake will be followed within 3 days by a large earthquake nearby is somewhere just over 6%. In California, that probability is about 6%. This means that there is about a 94% chance that any earthquake will NOT be a foreshock. In California, about half of the biggest earthquakes were preceded by foreshocks; the other half were not. At this time, we cannot...

#### What is the probability that an earthquake is a foreshock to a larger earthquake?

Worldwide the probability that an earthquake will be followed within 3 days by a large earthquake nearby is somewhere just over 6%. In California, that probability is about 6%. This means that there is about a 94% chance that any earthquake will NOT be a foreshock. In California, about half of the biggest earthquakes were preceded by foreshocks; the other half were not. At this time, we cannot...

#### What is the probability that an earthquake will occur in the Los Angeles Area? In the San Francisco Bay area?

Los Angeles area:Within the next 30 years the probability is:60% that an earthquake measuring magnitude 6.746% that an earthquake measuring magnitude 731% that an earthquake measuring magnitude 7.5will occur in the Los Angeles region.San Francisco Bay area:Within the next 30 years the probability is:72% that an earthquake measuring magnitude 6.751% that an earthquake measuring magnitude 720% that...

#### What is the probability that an earthquake will occur in the Los Angeles Area? In the San Francisco Bay area?

Los Angeles area:Within the next 30 years the probability is:60% that an earthquake measuring magnitude 6.746% that an earthquake measuring magnitude 731% that an earthquake measuring magnitude 7.5will occur in the Los Angeles region.San Francisco Bay area:Within the next 30 years the probability is:72% that an earthquake measuring magnitude 6.751% that an earthquake measuring magnitude 720% that...

#### What is the likelihood of a large earthquake at location X? Is it safe to go to X since they've been having a lot of earthquakes lately?

The National Seismic Hazards Mapping project provides an online Web tool for determining the probability of a large earthquake within 50 kilometers (~31 miles) of a specific location in the United States over a certain time period. The calculation is based on the latest available information from seismic hazard data.However, asking if it's safe to travel somewhere because of recent earthquakes is...

#### What is the likelihood of a large earthquake at location X? Is it safe to go to X since they've been having a lot of earthquakes lately?

The National Seismic Hazards Mapping project provides an online Web tool for determining the probability of a large earthquake within 50 kilometers (~31 miles) of a specific location in the United States over a certain time period. The calculation is based on the latest available information from seismic hazard data.However, asking if it's safe to travel somewhere because of recent earthquakes is...

#### How do I decide whether or not to get earthquake insurance?

You should consider the following factors when deciding whether or not to get earthquake insurance:proximity to active earthquake faultsseismic history of the region (frequency of earthquakes)time since last earthquakebuilding construction (type of building and foundation)architectural layoutmaterials usedquality of workmanshipextent to which earthquake resistance was considered by the...

#### How do I decide whether or not to get earthquake insurance?

You should consider the following factors when deciding whether or not to get earthquake insurance:proximity to active earthquake faultsseismic history of the region (frequency of earthquakes)time since last earthquakebuilding construction (type of building and foundation)architectural layoutmaterials usedquality of workmanshipextent to which earthquake resistance was considered by the...

#### How will my house hold up in an earthquake? Can the USGS send someone out to evaluate my property?

Published maps will only provide generalized, uninterpreted information about specific areas. Every property consists of a unique combination of geologic and structural factors that must be considered to determine what might happen to a house during an earthquake. Therefore, an individual site study is necessary. Geologic factors include: type of underlying material, depth to bedrock, depth of...

#### How will my house hold up in an earthquake? Can the USGS send someone out to evaluate my property?

Published maps will only provide generalized, uninterpreted information about specific areas. Every property consists of a unique combination of geologic and structural factors that must be considered to determine what might happen to a house during an earthquake. Therefore, an individual site study is necessary. Geologic factors include: type of underlying material, depth to bedrock, depth of...

#### What are the earthquake hazards/risks where I live?

Determining your risk with regard to earthquakes, or more precisely shaking from earthquakes, isn't as simple as finding the nearest fault. The chances of experiencing shaking from an earthquake and/or having property damage is dependent on many different factors. The National Hazard Maps use all available data to estimate the chances of shaking (of different strengths and frequencies) across the...

#### What are the earthquake hazards/risks where I live?

Determining your risk with regard to earthquakes, or more precisely shaking from earthquakes, isn't as simple as finding the nearest fault. The chances of experiencing shaking from an earthquake and/or having property damage is dependent on many different factors. The National Hazard Maps use all available data to estimate the chances of shaking (of different strengths and frequencies) across the...

#### What is seismic hazard? What is a seismic hazard map? How are they made? How are they used? Why are there different maps, and which one should I use?

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. The maps are made by considering what we currently know about:Past faults and earthquakesThe behavior of seismic waves as they travel through different parts of the U.S. crustThe near-surface site conditions at specific locations of...

#### What is seismic hazard? What is a seismic hazard map? How are they made? How are they used? Why are there different maps, and which one should I use?

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. The maps are made by considering what we currently know about:Past faults and earthquakesThe behavior of seismic waves as they travel through different parts of the U.S. crustThe near-surface site conditions at specific locations of...

#### United States Geological Survey (USGS) Natural Hazards Response

#### Putting down roots in earthquake country-Your handbook for earthquakes in the Central United States

#### Earthquake hazards: a national threat

#### Putting down roots in earthquake country: Your handbook for the San Francisco Bay region

#### East vs West Coast Earthquakes

Why was an earthquake in Virginia felt at more than twice the distance than a similar-sized earthquake in California? The answer is one that many...

#### Assessing Critical Infrastructure Damage After Earthquakes

Early on the morning of August 24, 2014, Loren Turner was awoken by clattering window blinds, a moving bed, and the sound of water splashing out of...

#### New Audiences, New Products for the National Seismic Hazard Maps

#### 20 Years After Northridge Quake, Buildings Remain Vulnerable

## Related Content

- FAQ
#### What is the USGS doing to mitigate and respond to earthquake hazards?

The U.S. Geological Survey performs the following functions related to earthquake hazard mitigation:Receives, analyzes, maintains, and distributes data on earthquake activity worldwide. Satellites link our National Earthquake Information Center in Golden, Colorado to a network of seismograph stations. These stations, located throughout the world, are maintained by the U.S. Geological Survey, State...

link#### What is the USGS doing to mitigate and respond to earthquake hazards?

#### How are engineers working to make roads and buildings safer?

Earthquake engineers are working to make roads and buildings safer in the event of a major earthquakes. This includes both improving the design of new buildings and bridges as well as strengthening older units to incorporate the latest advances in seismic and structural engineering. The Federal Emergency Management Agency plays a central role in funding research and development for the purpose of...

link#### How are engineers working to make roads and buildings safer?

#### How do I get earthquake hazard maps for locations outside of the U.S.?

We know of no current "zone" designations for sites outside of the United States. For locations outside the United States for which seismic design is required for military facilities, there exists a standard based on probabilistic spectral ordinates in the manner of the International Building Code and are declared to reflect the 2015 version of that code. These spectral ordinates can be found in...

link#### How do I get earthquake hazard maps for locations outside of the U.S.?

#### Can the National Seismic Hazard Maps be used as an earthquake forecast tool for the near future?

Not really. The USGS Seismic Hazard Maps website and the Unified Hazard Tool (for building custom maps) are designed to display the probability of different events that might occur in a several-year to several-decade period. The model bases all probability estimates on the average rate of earthquakes over long periods of time.As you shorten the time window, you should expect greater and greater...

link#### Can the National Seismic Hazard Maps be used as an earthquake forecast tool for the near future?

#### What is the difference between earthquake early warning, earthquake forecasts, earthquake probabilities, and earthquake prediction?

The USGS uses these four terms to refer to four different things.Early warning is a notification that is issued after an earthquake starts. Probabilities and forecasts are comparable to climate probabilities and weather forecasts, while predictions are more like statements of when, where, and how large, which is not yet possible for earthquakes.Here are more detailed descriptions of each...

link#### What is the probability that an earthquake is a foreshock to a larger earthquake?

Worldwide the probability that an earthquake will be followed within 3 days by a large earthquake nearby is somewhere just over 6%. In California, that probability is about 6%. This means that there is about a 94% chance that any earthquake will NOT be a foreshock. In California, about half of the biggest earthquakes were preceded by foreshocks; the other half were not. At this time, we cannot...

link#### What is the probability that an earthquake is a foreshock to a larger earthquake?

#### What is the probability that an earthquake will occur in the Los Angeles Area? In the San Francisco Bay area?

Los Angeles area:Within the next 30 years the probability is:60% that an earthquake measuring magnitude 6.746% that an earthquake measuring magnitude 731% that an earthquake measuring magnitude 7.5will occur in the Los Angeles region.San Francisco Bay area:Within the next 30 years the probability is:72% that an earthquake measuring magnitude 6.751% that an earthquake measuring magnitude 720% that...

link#### What is the likelihood of a large earthquake at location X? Is it safe to go to X since they've been having a lot of earthquakes lately?

The National Seismic Hazards Mapping project provides an online Web tool for determining the probability of a large earthquake within 50 kilometers (~31 miles) of a specific location in the United States over a certain time period. The calculation is based on the latest available information from seismic hazard data.However, asking if it's safe to travel somewhere because of recent earthquakes is...

link#### How do I decide whether or not to get earthquake insurance?

You should consider the following factors when deciding whether or not to get earthquake insurance:proximity to active earthquake faultsseismic history of the region (frequency of earthquakes)time since last earthquakebuilding construction (type of building and foundation)architectural layoutmaterials usedquality of workmanshipextent to which earthquake resistance was considered by the...

link#### How do I decide whether or not to get earthquake insurance?

#### How will my house hold up in an earthquake? Can the USGS send someone out to evaluate my property?

Published maps will only provide generalized, uninterpreted information about specific areas. Every property consists of a unique combination of geologic and structural factors that must be considered to determine what might happen to a house during an earthquake. Therefore, an individual site study is necessary. Geologic factors include: type of underlying material, depth to bedrock, depth of...

link#### How will my house hold up in an earthquake? Can the USGS send someone out to evaluate my property?

#### What are the earthquake hazards/risks where I live?

Determining your risk with regard to earthquakes, or more precisely shaking from earthquakes, isn't as simple as finding the nearest fault. The chances of experiencing shaking from an earthquake and/or having property damage is dependent on many different factors. The National Hazard Maps use all available data to estimate the chances of shaking (of different strengths and frequencies) across the...

link#### What are the earthquake hazards/risks where I live?

#### What is seismic hazard? What is a seismic hazard map? How are they made? How are they used? Why are there different maps, and which one should I use?

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. The maps are made by considering what we currently know about:Past faults and earthquakesThe behavior of seismic waves as they travel through different parts of the U.S. crustThe near-surface site conditions at specific locations of...

link - Multimedia
- Publications
#### United States Geological Survey (USGS) Natural Hazards Response

The primary goal of U.S. Geological Survey (USGS) Natural Hazards Response is to ensure that the disaster response community has access to timely, accurate, and relevant geospatial products, imagery, and services during and after an emergency event. To accomplish this goal, products and services provided by the National Geospatial Program (NGP) and Land Remote Sensing (LRS) Program serve as a geos#### Putting down roots in earthquake country-Your handbook for earthquakes in the Central United States

This handbook provides information to residents of the Central United States about the threat of earthquakes in that area, particularly along the New Madrid seismic zone, and explains how to prepare for, survive, and recover from such events. It explains the need for concern about earthquakes for those residents and describes what one can expect during and after an earthquake. Much is known about#### Earthquake hazards: a national threat

Earthquakes are one of the most costly natural hazards faced by the Nation, posing a significant risk to 75 million Americans in 39 States. The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes happen, and (2) providing critical and timely information to improv#### Putting down roots in earthquake country: Your handbook for the San Francisco Bay region

This handbook provides information about the threat posed by earthquakes in the San Francisco Bay region and explains how you can prepare for, survive, and recover from these inevitable events. If you live or work in the region, you need to know why you should be concerned with earthquakes, what you can expect during and after a quake, and what you need to do beforehand to be safe and reduce damag - News
link
#### East vs West Coast Earthquakes

Why was an earthquake in Virginia felt at more than twice the distance than a similar-sized earthquake in California? The answer is one that many...

link#### Assessing Critical Infrastructure Damage After Earthquakes

Early on the morning of August 24, 2014, Loren Turner was awoken by clattering window blinds, a moving bed, and the sound of water splashing out of...

link#### New Audiences, New Products for the National Seismic Hazard Maps

New Audiences, New Products for the National Seismic Hazard Mapslink#### 20 Years After Northridge Quake, Buildings Remain Vulnerable

Twenty years ago this week an earthquake struck Northridge, Calif., killing 57 people and revealing a serious defect in a common type of mid-rise...