Is your land near an active fault? Checking the fault map on your phone
One of the first questions people ask before buying land: is it close to a fault? The answer is not a single distance value. The fault map shows where the fault runs; how the ground will behave is a separate study.
Field takeaways
- An active fault has moved recently in geological terms and can move again.
- In Türkiye the official source is the MTA active fault map and database.
- Distance to a fault alone is not enough; soil type, groundwater and building quality also matter.
- A map layer on a phone gives preliminary information, not an official ground survey.
- With MapLab Survey you can locate your parcel, measure the distance to the mapped fault and save the result with notes and photos.
What an active fault means
A fault is a fracture plane in the crust. An active fault has moved recently in geological terms and is expected to move again. In Türkiye the official reference is the MTA renewed active fault map and database. The line you see on a map is the surface projection of the fault, drawn at a particular scale, so it should not be read as an exact boundary.
What distance does and does not tell you
Proximity matters for surface rupture, which is a direct threat to structures sitting on the fault. Most earthquake damage, however, comes from how shaking behaves in the ground. Loose alluvial soil, shallow groundwater and liquefaction potential can make a distant parcel riskier than a closer one on solid rock.
Checking it in the field
Locate the parcel, switch on the fault layer, measure the distance from the parcel boundary to the mapped line, then save the result with a note and a photo. MapLab Survey keeps these steps in one project and exports a PDF report or KML.
What comes next
A map check is a first step. Before building, a geotechnical ground and foundation survey is required. Drilling and laboratory work show bearing capacity, settlement behaviour and liquefaction potential. Combine that with the municipal zoning status and the national seismic hazard values before making a decision.
See it in action
MapLab Survey | Professional Mobile GIS, GPS Surveying & Land Measurement App
Visit the YouTube channel ->Try these steps on your own phone.
MapLab Survey handles RTK/GNSS point capture, drawing, area and volume calculations and coordinate conversion, then exports to DXF, KML/KMZ, GeoJSON, Shapefile, GeoPackage, NCZ or CSV. Capture, calculation and export work offline. Live NTRIP corrections and online basemaps need a connection.
Frequently asked questions
How do I check my land against the fault map?
Locate the parcel, switch on the active fault layer and measure the distance. The official line data comes from the MTA active fault maps.
What distance is safe?
There is no single safe distance. Surface rupture risk drops with distance, but soil type and liquefaction potential matter too.
Does the app replace an official document?
No. It is preliminary information. A geotechnical survey and municipal zoning records are required.
Can MapLab Survey measure the distance?
Yes, and it saves the result with notes, photos and exportable reports.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Parcel query layer · Parcel query on phone · Land as it used to be · MapLab Survey