Oct 7
Seismic Prediction with Data: What is an Earthquake Map?
- Işık Arda Yardımsever
- 19 hours ago
- 5 min read
Earthquakes have always been a topic of discussion throughout history due to their sudden development and destructiveness. As long as the Earth's lithosphere, or upper crust, continues to move, they will continue to occur, and there is no technology that can prevent these disasters. Therefore, it is up to us humans to act based on data and take precautions. Thanks to geographic information systems (GIS), we can develop applications such as fault line movement and recent earthquake maps. So, what is an earthquake map, why is it used, and what are its uses? Before using our interactive earthquake maps, you can learn more in this short blog post.
Contents
What is an Earthquake Map?
An earthquake map shows how strongly an earthquake can shake the ground in a region. This force is measured by "peak ground acceleration," which indicates how fast the ground is moving at the time of the earthquake. This helps determine which areas are most likely to experience an earthquake and which structures are at greater risk.
What is the Use of an Earthquake Map?
Earthquake maps provide a visual understanding of potential earthquake risk in a region. These maps help make safe decisions in areas such as residential planning, building design, and disaster management. This increases the resilience of structures and reduces the risk of loss of life.
How to Read and Interpret an Earthquake Map?
An earthquake map represents the intensity of shaking in areas marked with different colors. The darker the color or the higher the value, the stronger the ground shakes in that area during an earthquake. Earthquakes are displayed as point values on Cartographero's interactive earthquake map. Less intense earthquakes are marked with blue dots, while more intense earthquakes are marked with red dots. The colored areas surrounding the dots indicate the areas where the shaking was felt.
Why is an Earthquake Map Used?
Earthquake maps are used to ensure building safety and minimize earthquake damage. Engineers use these maps to make appropriate material and design choices when constructing new structures. They are also a key resource for raising risk awareness for the public and administrators.
Sectors Using Earthquake Map:
Construction industry: Used to create durable designs in building and infrastructure projects.
Urban planning: Ensures that new residential areas are established in safe areas.
Disaster management: Helps prepare emergency plans in risky areas.
Insurance sector: It is taken as a reference in determining earthquake insurance premiums.
Education and research: Used in scientific studies and awareness projects regarding earthquake risk.
Public institutions: Use it to develop earthquake-resistant zoning policies and building inspections.
Earthquake Map Types and Differences
Because the variety of thematic maps available today is so extensive, multiple maps can be created for a single factor to be analyzed. The same can be said for earthquake maps: specialized mapping can be created for points, hazard zones, fault lines, seismic gaps, and past earthquakes. While these GIS datasets are relatively from the same source, the resulting results offer different analysis opportunities, and therefore, diversity is important.
Point Earthquake Map
These earthquake maps mark the focal point of the disaster and display the information there. For example, data from the October 8 Balıkesir earthquake, measured at a magnitude 6.1, is collected directly from the red dot, providing a single window for data such as the time of the earthquake, its intensity, and its coordinates.
Earthquake Hazard Map
A hazard zone seismic map is a map that shows the earthquake risk levels of different areas within a country or region. This map classifies regions according to different hazard levels, taking into account factors such as crustal mobility, the location of fault lines, past earthquakes, and soil structure. These maps, often represented by color tones, are critical for building planning, establishing construction standards, and disaster management.
Fault Lines Map
Rather than simply earthquakes, a fault line map visualizes and categorizes existing tectonic plates and fault lines. This map helps identify areas of the Earth's crust where tension, compression, or shear are concentrated. This allows us to clearly identify areas at high risk of earthquakes, active fault zones, and plate boundaries.
Additionally, engineers, urban planners, and geologists can use these maps to assess the safety of new residential areas, plan infrastructure projects, and develop risk mitigation strategies.
Seismic Gap Map
A Seismic Gap Map is a map created by geophysicists that shows sections of an active fault that have not exhibited significant seismic activity for an extended period. These maps are used to guide scientists and authorities in identifying areas at greatest risk for future earthquakes and intensifying earthquake preparedness, construction, and mitigation efforts in these areas.
Past Earthquakes Map
A map of past earthquakes serves as an archive and helps analyze disaster risk for projects or construction in the region. These maps also determine the level of future seismic hazard by revealing the historical activity and earthquake recurrence intervals of a fault segment, guided by geology and seismology. This vital data provides a scientific and legal basis for urban planners and civil engineers to raise building inspection standards in at-risk areas, prioritize urban renewal zones, and design critical infrastructure facilities (hospitals, bridges, power lines) based on expected peak ground acceleration.
Where are the Earthquake Zones on the Map?
An earthquake zone map is an official document that ranks the seismic risk of a country or region. These maps are prepared by analyzing historical earthquake data, the location of active fault lines, and geological structure. They typically include ratings ranging from Grade I (highest risk) zones to areas with the lowest earthquake risk. Risky zones are areas where high ground acceleration values are expected and, therefore, require special precautions in construction.
What is the difference between fault lines and earthquake zones?
Fault lines are fractures or cracks in the Earth's crust that form as a result of tensions, causing rocks to move relative to each other. An earthquake zone is a large geographic area determined by the proximity of a fault line and its past seismic activity. In other words, a fault line represents the tectonic structure that is the source of an earthquake, while a seismic zone describes the broad risk area that would be affected by tremors originating from that fault line. Therefore, a region does not necessarily have to be directly located on a fault line to be considered an earthquake zone; proximity to a fault line also determines the risk.
How to Prepare an Earthquake Map?
Most web maps today, including earthquake maps, are created using ArcGIS or similar applications. This technology allows maps to be both user-focused and quickly integrated with data. Interactive web maps are created using these mapping applications as follows:
Data Source and Update: The map is continuously updated by connecting to the USGS's live earthquake data API in GeoJSON format.
Transfer to GIS Environment: The captured JSON data is transferred to ArcGIS Pro or Online platform, converted into geographical features (Point Features) and placed on coordinates.
Symbology and Visualization: Earthquakes are symbolized in different colors and sizes according to their magnitude; magnitude, depth, and time information are displayed in pop-up windows that open upon user click.
Integrating Risk Layers: An analytical risk assessment is performed by adding layers of active fault lines and critical infrastructure (hospitals, schools, bridges, etc.) to the map.
Interactive Dashboard Publishing: Prepared layers are converted into a control panel containing counters, charts, and filters on ArcGIS Dashboards and published as a web service.
If you liked this information, also visit our interactive earthquake maps:
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