Mapping Earthquakes in Northern California

Table of Contents

  1. Mapping Earthquakes in Northern California
  2. Setting Up Your Workspace
  3. Downloading Data from Natural Earth
  4. Download Data from the Northern California Earthquake Data Center (NCEDC)
  5. Skill Drill: Download Data from the United States Census Bureau
  6. Adding California as a Basemap Layer
  7. Skill Drill: Adding the Humboldt County Boundary as a Basemap Layer
  8. Adding XY Data
  9. Changing the Map Projection of the Data Frame
  10. Representing Earthquake Magnitude Using Graduated Symbols
  11. Changing the Map Size and Position
  12. Creating an Inset Map
  13. Inserting A Map Title
  14. Inserting a Map Legend
  15. Inserting a North Arrow, Scale Bar, and Acknowledgments
  16. Exporting your map as a PDF file

Changing the Map Size and Position

When you first begin to design a map layout, you should always determine the size of the page on which you will be working. In this activity, you are making a poster-sized map of California earthquakes in 2017. The poster size will be 24 inches by 18 inches. You will include a main map of California and an inset map of Humboldt County.

By default, ArcMap sets the page size to 8.5 inches by 11 inches. This setting is rarely acceptable, both professionally and in courses taught at Humboldt State University. In this step, you will change the page size. Then, you will change the data frame size and position on the page. From the main menu, select View, then Layout view.

An image of the Layout view option on the View menu
There are two ways to display the data frame in ArcMap, Data View, and Layout View.

The data frame window immediately changes to show the page size and the data frame position on the page. Across the top and along the left you will see a ruler indicating the height and width of the page. Currently, the page size is 8.5 inches by 11 inches, which is the default setting in ArcMap. The Layout toolbar may also appear floating above the map. You may dock the toolbar on top.

It is important to understand each of the tools in the Layout toolbar. These tools are only active when ArcMap is in Layout View.

An image of the Layout Toolbar
The layout tools only work while in Layout View.

On the left of the toolbar, you’ll see two tools for zooming in and out of the map layout. The icon looks like a magnifying glass over a page. These tools are sometimes confused with the Zoom In and Zoom Out tool you previously worked with. They work in a similar fashion. Instead of zooming in and out of the data, the zoom tools on the Layout toolbar zoom in and out of the page layout. Likewise, the pan tool on the layout toolbar will pan across the page layout and will not move the data. Next to the Pan tool is the Zoom to Whole Page tool. This tool is handy for quickly viewing the entire page layout. Take a moment to experiment with each of these tools before moving on to the next step.

Next, you will change the page size. From the main menu, select File, then Page and Print Setup.

An image of the file menu page and print set up.
You can access contextual menus by right-clicking.

Uncheck the box next to Use Printer Paper Settings. For the Width, enter 24. For the Height, enter 18. When you are ready, click OK.

An image of the Map page size options for 24 by 18
Check the lower left corner of the Page and Print Setup window to change these settings.

The page is now a large poster size of 24 inches by 18 inches. You can tell because the ruler along the top and the sides have changed to show the new dimensions. However, the data frame is still the default size.

An image of the new page size with original data frame size
There are always two steps when setting up your map layout. Change the paper size and change the data frame size. Here you see an An image of the new page size with original data frame size Click to view a larger sized image.

To change the data frame size, open the data frame properties and navigate to the Size and Position tab. Change the width and the height values so that they match the page size. Under Position, change the X and the Y to 0.

An image of the Data frame size and position tab
By default, the Position value anchors the data frame on the page relative to the lower left corner. Click to view a larger sized image.

Navigate to the Frame tab. Change the Border to a thickness of 4.0 and change the border color to dark navy. Change the background color to light cyan. When you are ready, click OK. You may get another warning about the coordinate system. Click Yes to close the warning.

An image of the Data frame properties frame tab
Do not confuse the Frame tab with the Data Frame tab. Click to view a larger sized image.

On the Table of Contents, right-click on your earthquake layer and select Zoom to Layer. You should now have a poster size map of the earthquakes in California.

An image of the earthquake map at new size
When you Zoom to Layer, ArcMap changes the map extent so that the entire layer is centered on the page. Click to view a larger sized image.