The North Bend Eagle


 

Where in the geodetic world is North Bend?

by Mary Le Arneal
Published 4/11/12

There is a sign in North Bend that tells you to write Washington D.C.

No, it’s not at the post office or city hall, it’s in the area where the old water tower used to stand. It was first noted by this reporter on a walk from the bank to the post office, going the back way. The sign reads:

WITNESS POST
PLEASE DO NOT DISTURB
NEARBY SURVEY MARKER
For information write to
The Director
National Geodetic Survey
Department of Commerce
Washington, D.C. 20230

And so a letter was written in January, but nothing was heard for a month when a phone call was received from Jim Richardson, the National Geodetic Survey (NGS) State Geodetic advisor with the Nebraska State Highway Department in Lincoln.

Morse Bluff marker
Morse Bluff's Bench Mark

North Bend marker
North Bend's Bench Mark

But he could not talk to the press officially until a formal letter was received from the Dept. of Commerce - which had red tape to go through before it could be mailed.

Richardson did say that a brass plate, the official survey marker, would be within 20 feet of the witness post. A short search found the brass marker just inches from the post. A small circular disc, it was placed in a three-foot square of concrete. The mystery continued.

After receiving an official letter from Washington, D.C., along with the NGS Data Sheet about the marker, Richardson was again called upon to interpret the sheet.
What this marker does is relate where North Bend is on Earth. The local one was set in place in 1934, where as now markers are usually along railroad tracks. In 1934 there were markers every one to three kilometers.

The letter from the Dept. of Commerce said that the marker was set in the footing of the old water tower behind city hall. The bench mark served as part of a coordinate system comprised of marks used for geodetic positional and height coordinates. “Marks such as these accurately position both public and private points of interests.”

Richardson, a man passionate about his work, was excited to explain exactly what geodetic is.

“Geodetics is the gravitational model of the earth,” Richardson said. “The earth is spherical, not circular. Gravity is involved with surveying the earth. Gravity fields looks like a potato. The gravity shape of the earth is called geoid, it roughly represents sea level.”

The NGS engages in research and development for the improvement of knowledge of the figure of Earth and its gravity field.

The marker in North Bend is a bench mark. Bench marks are points for which elevation has been determined. It is used to control other surveys and to monitor movement of and within Earth’s crust.

This is probably more information than the average reader wants to know. But the NGS says that these measurements and points have “been a major factor in the world-wide effort to develop more accurate values of the size and shape of the earth; helped determine the placement and design of many of the great civil works of the United States; served as the control surveys for the national mapping efforts of the United States Geological Survey; helped with many of the technical aspects of our Nation’s defense; determined many state boundaries within our United States as well as the boundaries of many of the nations of the Americas; and helped determine property lines throughout much of our nation.”

But wait - there is more. When a map of this marker was pulled up on Google earth it showed more markers in North Bend and three in Morse Bluff. The only problem is that the location uses old, no-longer-in-existence landmarks to describe the location, for example, the North Bend train depot. There is one 1.15 miles east of North Bend, another 2 miles west (at Bay Station) and one in the city park. There is also one “set in the top of the south end of the southwest wingwall of the Platte River Bridge.” In Morse Bluff there is one east of the north door of the High School - another old landmark. In searching for the markers at the park, bridge and school, the only one found was the one at the school. It is obvious, set in the brick on the east side of the front door.

So now the world can find North Bend and Morse Bluff using these bench marks. And now we know what they mean.

Mystery solved.

Lesson learned.

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