Exploring Seismology in the Classroom Using the USGS Earthquake Hazards Program DataAccess Earthquake Data from the USGS Earthquakes Hazards Program (EHP)
Earthquake Data from the USGS Earthquakes Hazards Program (EHP) provide data on global earthquakes for the last 7 days and highlights the history of earthquake occurrences around the world. Earthquakes are represented on maps with links to data including latitude, longitude, magnitude, and time. Symbols representing earthquakes are varied in size, representing magnitude, and in color, representing time of earthquake occurrence (within the last hour, the last 24 hours, or the last 7 days). The site also provides general trends and statistics, documentation of the largest earthquakes to ever occur, the most destructive in history, those with high death tolls, earthquakes listed by year, and the 15 largest US earthquakes.
Use and Relevance
The National Earthquake Information Ceneter (NEIC) is part of United States Geological Survey (USGS) Earthquake Hazards Program (EHP). Data from the EHP are used by response agencies to determine how to direct resources. Scientists use this dataset to determine how earthquakes effect an area and whether seismic data can be used to predict future earthquakes. Engineers use this dataset to study how shaking effects structures and how structures can be built to withstand damage.
Use in Teaching
This dataset can be used to teach the following topics and skills in geophysics and structural geology:
- Natural hazards
- Solid earth
- Plate tectonics
- Seismic networks
- Understanding the collection and transmission of seismic data
- Interpreting earthquake data parameters, including location, depth, and magnitude
- Using seismic data to map plate boundaries
- Using seismic data to determine the highest probability area where an earthquake might occur
- Examining relationships between earthquake parameters and the underlying rock structure
The Earth Exploration Toolbook has a chapter on Investigating Earthquakes: GIS Mapping and Analysis that uses USGS and IRIS data to conduct GIS analyses. Users interpret earthquake distribution and activity and analyze the potential for predicting future earthquakes.
Exploring the Data
Data Type and Presentation
Data are represented graphically on maps, illustrating earthquake location, magnitude, and time. Symbols are used to represent the magnitude of the earthquake. The relative size of the symbol is proportional to magnitude, while the symbol colors represent whether the earthquake occurred in the last hour, day, or week. Recent and historical data are provided graphically and information about specific earthquakes (such as latitude, longitude, time, and depth) is presented in HTML format as a preliminary earthquake report.
Accessing the Data
Data can be accessed in several formats including:
- Latest Earthquakes: This section provides maps of earthquakes on a global scale and for the USA. Maps are provided at a high resolution for earthquakes within the US.
Maps depicting earthquake location can be accessed and downloaded as GIF files by choosing USA or World maps that can be explored further by selecting specific regions. Earthquakes are depicted on maps as squares (representing magnitude and time). Preliminary Earthquake reports, which provide information including latitude, longitude, location, and depth, can be obtained by clicking on the earth quake symbol. The reports also provide access to summary information for earthquakes in that region and maps of the regions in various formats, including seismic hazards maps and USGS aerial photos. Scientific data and technical information provide historical moment tensor solutions (similar to fault-plane solutions) and theoretical P-wave travel times.
- Feeds and Data: This section provides a variety of interfaces for examining real-time global earthquakes.
- RSS (Really Simple Syndication) Feeds: Users can sign up to receive feeds providing information on magnitude, location, date, and time for recent earthquakes.
- Google Earth and KML files: This section allows users to view KML files of real-time earthquakes in Google Earth. Clicking on the KML links within the USGS page will automatically start up Google Earth and open that particular view of the data.
- CSV files: This section allows users to download ASCII files that provide data on location, depth, magnitude, and time for earthquakes occurring in the last hour, 24 hours, or 7 days.
- Recent Earthquakes: This section provides a list of of global earthquakes for the last 8 to 30 days.
Users can download Earthquake Reports in HTML format for earthquakes occurring during the past 8 to 30 days (includes latitude, longitude, depth, time, tensor moments, and theoretical P-wave travel times data.
- Historic Earthquakes: This section provides access to data and information on significant, high impact historic earthquakes.
- The 'Top 10 Lists and Maps' section provides a variety of data sources and statistics, including a map illustrating the location and intensity of damaging earthquakes in the US from 1750 through 1996, and tables providing information on number of deaths from historic earthquakes.
- The 'Significant EQs' section provides links to Earthquake Reports in HTML format for earthquakes occuring globally from 1692 through 2006.
- The 'Earthquake Search' query option allows users to search download earthquake data, including location (latitude and longitude)and magnitude in a variety of formats including comma delimited HTML format, tabular HTML format, and maps that can be downloaded as GIF images.
- http://earthquake.usgs.gov/earthquakes/dyfi/ 'Did You Feel It?': This section provides archived information on earthquake intensity and damage that is provided by citizens who have felt an earthquake and reported information to the USGS 'Did You Feel It?' data collection site.Users can obtain data by choosing a region of interest from the US map, which provides a list of recent and historic earthquakes. Users can choose a specific earthquake to obtain a map (as a GIF image) that displays earthquake shaking and damage data. To get detailed information on reported data, users can access the statistics for the earthquake they are examining. The statistics page provides data including distance from epicenter, number of reports, and reported intensity levels.
Manipulating Data and Creating Visualizations
- One way that students can process this dataset is to superimpose earthquake locations onto a global map. This process will allow students to visualize the relationship between earthquake locations and plate tectonic boundaries.
- Students could also process data by importing tabular earthquake data into a spreadsheet application such as Excel to graph the number of earthquakes per day or to calculate and graphically represent averages over time.
Tools for Data Manipulation
- Real-time earthquake data are presented as KML files (files that are used to display information in Google Earth). In order to use this feature, users need to first download (more info) Google Earth (a free version is available). Accessing the USGS KML files allow users to display real-time data (including magnitude, location, and time since earthquake) using Google Earth.
- Raw data can be downloaded and imported into a spreadsheet application such as Excel for further processing. The Starting Point site provides a tutorial for using Excel.
About the Data
Collection MethodsData are collected by seismic instruments and transmitted to a central computer via several mechanisms including the internet, phone lines, microwave telemetry, or satellites. The USGS EHP maintains FAQs related to measuring earthquakes.
Limitations and Sources of ErrorBackground noise is a common source of error in seismographic data. Sensors pick up vibrations, resulting in a low noise background. Conversely sensors can become saturated when the magnitude of shaking is off scale. Errors also occur in transmission of data and their is background noise in transmission of data via microwave telemetry.
References and Resources
Scientific References that Use this Dataset
Education Resources that Use this Dataset
- The Earth Exploration Toolbook has two chapters Investigating Earthquakes with ArcVoyager GIS and Investigating Earthquakes with ArcExplorer GIS that use USGS and IRIS data to conduct GIS analyses. Users interpret earthquake distribution and activity and analyze the potential for predicting future earthquakes.
Other Related Scientific References
- 'Earthquake prediction: A seismic shift in thinking' is a article from Nature that discusses the debate regarding accuracy in predicting earthquakes.
- 'Mantle Convection and Plate Tectonics: Toward an Integrated Physical and Chemical Theory' is an article from Science that reviews the physics of plate tectonics.
Other related Education Resources
- The Broadband Seismic Data Collection Center maintains an education section with activities of relevance to students and teachers.
- The USGS EHP maintains a http://earthquake.usgs.gov/learn/index.php 'Learning and Education' section that contains numerous links to educational content and activities about earthquakes.
- The USGS EHP provides a http://earthquake.usgs.gov/learn/glossary/ 'visual glossary' of terms relevent to studying earthquakes.
- Mapping Plate Boundaries is an interactive lecture example from Starting Point.
- The Teach the Earth Portal contains teaching activities related to plate tectonics and earthquakes.
- The Seismological Society of America website contains information on earthquakes and a collection of issues related to teaching about earthquakes.
- Earthquake preparedness information is available from FEMA.
- The National Geographic website Forces of Nature (more info) provides information on natural hazards, including earthquakes.
- Earthquake FAQs
- Earthquake Resources for teachers