Teach Map # 0001 – Utah’s Land Surface

Teachers and others can use this map as a base map (meaning, put other information across it), as a teaching tool about models (this map is not an image from a satellite or a composite of aerial photography, it was generated by math!), or for the JOY factor of recognizing a familiar place or patterns. The patterns of this map show steepness of terrain. Note how western Utah looks so differently than eastern Utah.

Full citation: Experimental digital shaded-relief maps of Utah — IMAP 1847, by Kathleen Edwards and R.M. Batson https://doi.org/10.3133/i1847 Adequate attribution: USGS I-map 1847.

gray-scale shaded relief map of Utah by USGS scientists
This map is show steepness of Utah’s land surface using a mathematical model. It’s called shaded relief.

Maps as models. Models as maps.

A model is a representation. So… all maps are models because they are a paper-representation of some place that is “real” meaning physical. We can debate that later. Can a mathematical model become a map? This map was not created from images taken by a satellite. It’s not a composite of air photos taken from an airplane. Its authors created it with math. Their mathematical model used an intense number of elevation points calculated for Utah’s land surface. Then the USGS scientists calculated steepness between those points by calculatingthe differenc of elevation of the point and their distance between points. The technical term for the steepness of this map is “relief.” They then add “shaded relief” which made shadows, mathematically. For your information, “GIS spells j o b!” Geographic information systems (the toolbox for mathematical maps) are essential tools needed for many technical jobs in industry and government.

A relief map is a map that shows contrasts of steepness.

Glossary term.

Every place on Earth’s surface has “elevation” meaning the data are continuous Elevation indicates height above a datum. Topographic maps in the U.S. generally show elevation as feet above sea level. For example, the “average elevation of Great Salt Lake is 4200 ft a.s.l.

Concept alert.

Cause and Effect.

Utah’s land surface (topography) today is the product of Utah’s geologic past. The cumulative effects of tectonics and erosion from past to present have created this surface and continue to change it. The patterns of western Utah (left side of this map) should look different to you than the patterns on the right side of the map (eastern Utah). Put differently, if tectonics and erosion/deposition cause Utah’s surface to look the way it does today, we should be able to figure out some of Utah’s past by understanding Utah’s surface today. Even before we appreciated the imprtance of tectonics, geography drew

Utah’s three regions using contrasts of Utah’s landforms meaning the eviedcne sown on this map.

Enjoy this map! The JOY of patterns.

Can you locate Utah Lake in Utah County? It is blank, meaning white with almost no black on the map because it is so flat in reality. The surface of lakes is really flat and exceptionally horizontal!

Can you locate the Book Cliffs of central-eastern Utah? They prevent easy transportation access between southeastern and northeastern Utah. I-70 runs just south of them because it can’t run through them.

How about the Wasatch fault zone? On the map, it looks abrupt and compact, like a boundary. We interpret it as the boundary between western and eastern Utah. Is the contrast of Great Salt Lake versus the Wasatch Range due to movement of the Wasatch fault zone and its predecessors? Yes, extensional tectonics explains it well and… erosion / deposition.

If you can see patterns, you can be a scientist… or an accountant… or a bank robber.

G. Atwood

See patterns! Just as motorcyclists ask you to “See motorcycles.”

Enjoy this map!

Can you locate Utah Lake in Utah County? It looks blank (white) because it it so flat (lake surface are really flat!). Can you find the Book Cliffs of eastern-central Utah? They block easy passage from southeasther to northeastern Utah. I-70 from Grand Junction to Greeen River, Utah runs just south of them.

How about the Wasatch Fault zone? Its pattern makes it look like a boundary beween western and eastern Utah. Yes.