When an earthquake strikes, it can result in loss of life, property and resources. Geospatial tools such as ArcGIS Pro can be used to plot fault lines and seismic activity.
What to expect with this tutorial on earthquake mapping
This GIS tutorial teaches you how to use USGS and ArcGIS Pro data to map earthquakes and geological faults using the area around Dallas, Texas as an example. This tutorial uses Landsat 8 images and seismic data from the USGS website. PCI Geomatica software is used to narrow down the geographic region within the image and pull out features such as geological fault lines.
GIS data for the fault line, along with seismic data from the USGS, can then be imported into ArcGIS Pro. Then, using ArcGIS Pro, the earthquake data will be interpolated using the “spline” tool to visually represent the earthquake magnitude as a raster layer. Finally, we will create a map showing the strength of the earthquake and the fault lines. Figure 1 shows the flow map of the tools and data you will use to create this map in ArcGIS Pro using Landsat 8 images and seismic data.
Landsat 8 and preparing geological faults
Could be Landsat 8 images It is freely accessible from the United States Geological Survey (USGS) website. After free subscription. In this tutorial, Landsat 8 (Set 2 Level 1) images are used. For more information about How to access photos, watch this video. Geological faults are extracted from Landsat 8 images using PCI Geomatica software. For information on how to use the free trial and how to use it to download PCI software, visit Professional Catalyst – CATALYST.EartH.
Extracting geological faults from PCI Geomatica
- Launch and create a new project.
- From the menu bar, click Tools.
- Click Trim/Subset from the set of options displayed.
- From the Trim/Subset window, set the input file to the Landsat 8 band 10 location.
- Set the output file to the name and location of the truncated data set.
- Make sure that input data is enabled, by checking the Raster (Landsat 8 band 10) box under the Available Layers section.
- Under Output raster size, click the box to specify the boundaries of the truncated data set.
- Click a clip.
After clipping, geological faults are extracted from the clipped data by following the steps described below:
- From the tools in the menu bar, select “algorithm librarian” from the drop-down menu.
- Select Analysis.
- Select Geological/Geophysical Analysis.
- Select Extract font(s).
- Select Open.
- Set the input file to the saved cut file.
- Click Run.
- From the results, right-click on “Extracted Features” and select Save As.
- From the Output Location section, set the output name and location.
- Make sure the file type is set to “ArcView Shapefile”. Click Save.
Find earthquake GIS data for an area of interest
In this tutorial, geological fault data helps validate seismic data for a geographic area. Seismic data can be retrieved from USGS Earthquake Catalog Using the steps below:
- Set the size to 2.5+.
- Use the drawing rectangle to define the geographical area.
- From Output Options, set the format to CSV.
- Set the order to Oldest Time First.
- Click Search.
Create a seismic map showing geological faults in ArcGIS Pro
After retrieving seismic data from USGS and extracting geologic fault lines from Landsat 8 (band 10), use the following steps to create a map in ArcGIS Pro:
- Open and create a new project in ArcGIS Pro.
- Select Add data.
- Switch to the location of the USGS earthquake data you retrieved.
- Click OK.
- Right click on the query table.
- From the XY data view, set the X field to Longitude. Set the Y field to latitude.
- Click OK.
- Type Spline and search for it from the search bar of the Geoprocessing Toolbox.
- From the Key window, set the entry point features for the downloaded earthquake data.
- Set the Z value to “Mag”.
- Click Run to create a raster.
Now add the processed geological fault data from Landsat 8 (Band 10) as an overlay to the earthquake magnitude raster dataset:
- Click the Add Data tool from the Map tab in the menu bar.
- Switch to the error data location.
- Click OK.