<p>Based on USGS (Department of the Interior – United States Geological Survey) toopgraphic maps, where on a 7.5 min Quadrangle map, the contour interval is commonly 40 feet.  Larger maps 15 min to 1'-2' maps the interval is commonly 80-100 feet.</p>

<p>All maps of the United States are commonly sourced from USGS based maps.  I am certain Google or Google's map provider is using USGS base maps.</p>

<p>Reference:
<a href="http://geology.isu.edu/geostac/Field_Exercise/topomaps/vert_scale.htm" rel="noreferrer">http://geology.isu.edu/geostac/Field_Exercise/topomaps/vert_scale.htm</a></p>

CC BY-SA 3.0
2015-08-23T18:43:12.977Z
2015-08-23T18:43:12.977Z
Earth Science Expatriate
<p>Is 80 feet some sort of standard?</p>

<p><a href="https://i.sstatic.net/OiLvL.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/OiLvL.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2015-08-24T15:59:38.733Z
It does so in the United States, but not everywhere.  For example, it uses [20 metre in Switzerland](https://www.google.ch/maps/@46.0516137,7.7862577,15z/data=!5m1!1e4).
gerrit
<topography>
Why does Google maps (in terrain mode) space thier topo lines 80 feet apart?
Steve H
# Why does Google maps (in terrain mode) space thier topo lines 80 feet apart?

(Asked by: username_0 on 2015-08-23)

Is 80 feet some sort of standard?

[![enter image description here](https://i.sstatic.net/OiLvL.jpg)](https://i.sstatic.net/OiLvL.jpg)

**Tags:** topography

> **Comments:**
> **username_1**: It does so in the United States, but not everywhere.  For example, it uses [20 metre in Switzerland](https://www.google.ch/maps/@46.0516137,7.7862577,15z/data=!5m1!1e4).  

---

## 1 answers

### Answer by username_2 on 2015-08-23. Score: 5

Based on USGS (Department of the Interior – United States Geological Survey) toopgraphic maps, where on a 7.5 min Quadrangle map, the contour interval is commonly 40 feet. Larger maps 15 min to 1'-2' maps the interval is commonly 80-100 feet.

All maps of the United States are commonly sourced from USGS based maps. I am certain Google or Google's map provider is using USGS base maps.

Reference:
<http://geology.isu.edu/geostac/Field_Exercise/topomaps/vert_scale.htm>


---

