Week 7: Investigating Earthquake Activity

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Getting to Know Spatial Querying in AEJEE

So far in this course, you have practiced querying, classifying, and symbolizing data. All of these efforts helped you to sort and organize the data displayed on the map so that you could look for relationships and patterns in data. Now you will use spatial and database querying to sift out even more details about the earthquake events of 2009.

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Launch AEJEE and Open the Earthquakes Project

• Launch AEJEE by double-clicking its icon on your desktop or by clicking its icon in the Dock (Mac) or Launch Bar (Win).
• Choose File > Open, navigate to ESRI/AEJEE/Data/EarthquakeAE, select the E_QuakesAE.axl file, and click Open.
• A global map opens, showing Continents, US States, and Lines of Latitude and Longitude.

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Add Earthquake Data From 2009

If you worked through the "Introduction to Mapping Tabular Data" section, then you can use the Add Data button to bring up the previously mapped earthquake data. Otherwise, you'll need to use Add Event Theme to map the 2009 earthquakes.

Choose ONE of the following two options to add 2009 earthquake data to the map.

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   Add 2009 earthquake data as a shapefile

• Click the Add Data button .
• Navigate to the csv_files folder. (Path: ESRI/AEJEE/Data/EarthquakesAE/csv_files)
• Choose the 2009EQ.shp shapefile that was automatically created and saved in the previous section.
• Click OK.

Show me the shapefile and map

Hide

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Map 2009 tabular earthquake data by longitude and latitude coordinates

To map the 2009 earthquake events using Longitude and Latitude coordinates:

• Choose View > Add Event Theme to open the Add Event Theme window.
• Click the Browse button and navigate to the file named 2009EQ.csv. (Path: ESRI/AEJEE/Data/EarthquakesAE/csv_files).
• Choose the 2009EQ.csv file and click OK.
• Choose Longitude for the X Field and Latitude for the Y Field.
• Draw the events using symbols that are Blue Circles with a point size of 5.
• Use the default Output Directory.
• Click OK.

Show me how

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1. Select View > Add Event Theme.
   
2. The data file is in the csv_files folder within the EarthquakeAE data folder. Click the Browse button.
   
3. Navigate to the csv_files folder within the EarthquakeAE data folder.
   
4. Choose the file named 2009EQ.csv. Click Open.
   
5. In the Add Event Theme window, define the coordinates and set the color and the size of the map symbols for the new features.
   
   • Table: ESRI/AEJEE/Data/EarthquakesAE/csv_files/2009EQ.csv
   • X field: Longitude
   • Y field: Latitude
   • Draw event using symbol with:
   • Style: Circle
   • Color: Blue
   • Size: 5
   • Use the default Output Directory.
   Click OK.

The 2009 Earthquakes will now be displayed on the map.

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Think Spatially about Earthquake Data

Begin by brainstorming questions that could be asked when thinking spatially about earthquakes. Some examples of questions you might ask:

• How many earthquakes occurred in Chile in 2009?
• Do all earthquakes occur near plate boundaries?
• How far is a given earthquake from a major city?
• Do earthquakes occur more frequently near coastlines?
• Are there more earthquakes at certain elevations?
• Do earthquakes appear to be more common in one geographic region than another?
• Are the deepest earthquakes more common around one type of boundary than another?

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Carry Out a Simple Spatial Query

On September 30, 2009 a Magnitude 7.5 earthquake struck Sumatra, Indonesia. The quake originated at a moderate depth of 81 kilometers. At the surface, over 1100 people were killed and 2650 buildings were damaged in the earthquake and subsequent landslides. Power and communications were disrupted. The earthquake was felt over a wide area and produced a small tsunami.

Imagine that you worked for an international disaster aid organization, and wanted to quickly identify Indonesian cities that might have been close enough to the quake to need your help.

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Select the Sumatra earthquake

• Turn on the 2009EQ layer by clicking the checkbox next to its name. Then click on its name in the Table of Contents to make it the active layer.
• Use a Query to locate the Sumatra earthquake:
• Click the Query Builder button .
• In the query builder, set up the following equation:
  (Month = 9) and (Day =30) and (Magnitude = 7.5).
• Click the Execute button.
• Click the Highlight and the Zoom To buttons. (Note: If clicking the Zoom button does not zoom in on the highlighted earthquake, you will need to zoom in manually using the Zoom In tool )


Show me how
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1. Turn on the 2009EQ layer by clicking the checkbox next to its name. Then click on its name in the Table of Contents to make it the active layer.
2. Use a query to locate the Sumatra earthquake:

• Click the query builder button .
• In the Query Builder window, set up the following equation:
  (Month = 9) and (Day =30) and (Magnitude = 7.5).
• Click the Execute button.

In the Query Results list at the bottom of the Query Builder window, click to select the single found record.

At the bottom of the query builder window, click the Highlight and Zoom buttons.

The map will zoom to center on the highlighted Sumatran earthquake. (Note: If clicking the Zoom button does not zoom in on the highlighted earthquake, you will need to zoom in manually using the Zoom In tool ).

Close the Query Builder window.