Marking A Bemchmark Destroyed

[+PittCaleb]

I like hunting benchmarks that no one else has visited. I think it would be great is all the BMs listed on GC.com have been visited at some point...

 

That said, I am very careful marking them 'destroyed' - I can't just "not find" it and assume it's destroyed - I have to know it was in fact destroyed (i.e. a local water tower was once a BM and it's clearly no longer there. Took photos of the concrete base, left description, marked destroyed at gc.com).

 

NE1555

 

Below are 2 photos of a BM that was visited by another in Ann Arbor a while ago. i wanted to double check. To me, this BM is *destroyed* although there is a legit witnes post and "survey marker" post. As you can see in both photos, someone literally dug this BM out of the ground - which surprises me in that I thought they would have been deeper.

 

So - is this BM destroyed? Should I contact someone to notify them of this destroyed BM?

 

Caleb

 

 

[+seventhings]

PittCaleb -

 

First, I would log this as "Didn't find it" in Geocaching.

 

Then, I would send an e-mail to Deb.Brown@noaa.gov describing the situation in sufficient detail (handheld GPS coordinates, measurements, etc) to assure her (and yourself) that you have positively found the former location of the station. I would attach your photos to the e-mail. See the pinned thread started by Deb for further guidance, photo naming conventions, etc.

 

In a few weeks, Deb (should and probably) will respond and either (1) ask you to submit a recovery report on the NGS datasheet page and categorize the station as "Poor, Disturbed" or (2) she will tell you that she has recalssified the station as "Destroyed". You can check the NGS datasheet periodically to see if the station has been reclassified.

 

If Deb/NGS reclassifies the station as destroyed, then I would go back and change my post from "Didn't find it" to "Destroyed", and edit the comments to say that the NGS has reclassified this station as "Destroyed".

 

The NGS datasheet page is at NGS Datasheet Page

 

Will

 

p.s. That tough-looking character in the photo is probably the perp.

Edited September 25, 2004 by seventhings

[+PFF]

10/8/2002 wreckdiver couldn't find NE1555    [visit log]

The witness post was there, and there was a large white X of plywood around the spot where it should have been, but there was only a hole in the ground.

 

It appears that this disk was removed between April 28, 1998 and October 8, 2002. [see entry from WreckDiver, above.] This clearly is worthwhile submitting to Deb Brown--especially since you have excellent photographs to include in your report.

 

It is a simply process. Just e-mail Ms. Brown with the facts as you presented them to our forum. Include the photos as attachments. Also include the means of determining that you were at the proper spot, such as GPS reading (and accuracy), landmarks agreeing with published description, etc.

 

Deb probably will not respond, in person. However, you will see it marked as "destroyed" in the NGS database within 30 days, if she agrees with your assessment.

 

-Paul-

[+PFF]

Opps. Sorry for the redundancy. It took an hour to get that message posted, due to interruptioning phone calls, etc. Will's answer is quite complete!

 

As for the photo, the expression on the boy's face is great. I was going to caption the picture, "Alright.....who stole the marker?"

 

Hmmm. That might be an ideal transfer to a Tee shirt--to be worn while benchmark hunting, of course!

 

-Paul-

[evenfall]

Hey All,

 

NGS criteria for Destroying a Station, in this case a physical Station Disc Monumentation, is very stringent. The reason for this is so that arbitrarily, no one can simply 'not find' a Station and declare it Destroyed. It is much less stringent for say, a building or tower, something that is not a disc type Station. You can well imagine what would be left in the database if it were so easy. So in the case of this Station type going missing, unless Somebody can Physically ship the destroyed objet to NGS, or provide a picture, close up enough to show the actual stamping to show that the actual object is in fact the actual object and it is destroyed. It sounds like all that is found is a hole in the ground. Due to the stringent requirements of the NGS, good ones in my thinking, it means that in 100 years from now, this station and all the others just like it, Meaning removed from their locations, with no proof of the actual removal, will be eternally not found.

 

In this case there is a twist however, but it is not going to change things much. This Station is not, and never was property of the NGS.

NE1555 OWNERSHIP--MICHIGAN

DEPARTMENT OF TRANSPORTATION.

What this means is that MDOT Monumented this Station and Surveyed it to a very high standard. This was a First order Horizontal Control and a Second order II Vertical control, which is not something the NGS commonly would set. The NGS primarily sticks to Triangulation Stations for Horizontal Control, and Bench Mark Stations for Vertical Control. For and NGS setting it was not really until GPS that many were doing High order accuracy on both at once.

 

Since this Station qualified to NGS standards of accuracy, MDOT submitted it for inclusion to NGS for inclusion in their Database. After the data was analyzed by NGS, it must have qualified, so it was added. Regardlessly, this Station is still property of the State of Michigan, not the NGS. At best to the NGS all that can be done is the submission of a standard recovery report to NGS with photos that it is Not Found and a description stating that the Station has been physically removed from the location... I would dig a little in the hole myself just to make double sure.

 

After or during the NGS report I would also Contact the Michigan State Geodetic Advisor,

 

Dave Rigney, NOAA/NGS

State Transportation Building

Design Survey Division P.O. Box 30050

Lansing, MI 48909

Telephone: 517-377-1510, Fax: 517-241-4631

Dave.Rigney@noaa.gov

 

Most State Advisors are Dual Duty. They Work for the State, and the do duty for the NGS as their Representative in that State. They are 2 birds with one stone.

 

Dave will know how to handle this both for the NGS and the State of Michigan, and he has the only Field Authority to truly establish, officially, that this Station has been destroyed. I would not Go to Deb Brown on this, as all she can do is ask you to submit a not found report, and advise you to contact Dave. It would be true whether this were an NGS Station or a State Owned Station. Dave can physically go to the spot look at it and take the action he deems appropriate.

 

The main thing here is this. This is part of what State Geodetic advisors are for. It Takes a State Advisor to Officially Destroy a Ground Station. There is a great deal of planning that goes into the establishment of a First Order Station. It took a great deal of observation to establish it, and it is good to know it is gone missing. Your report to them may even cause them to establish a new one in that area if they truly need the control.

 

I hope this helps, and this scenario would hold true for similar situations in any State.

 

Happy Hunting!

 

Rob

 

Edit for a Typo.

Edited September 25, 2004 by evenfall

[+seventhings]

PittCaleb -

 

evenfall knows a lot more about this than most of us. Therefore, disregard what I said (except for the part about logging it as "Didn't find it" for the time being) and do what he said.

 

Will

[mloser]

One more thing--benchmarks are typically set in posts that are about 3 feet in length. To dig one out would require more than just disturbing the surface, which is what appears happened in your pic. The perp would have had to dig 2 to 3 feet down to get the entire monument out of the ground, unless the top of the concrete monument was knocked off. Is there evidence of the monument in the hole at all? Also, is the hole the correct distance from the old witness post, as described ?

In the more distant pic it looks like the ground has been disturbed for quite an area around the marker, so it is possible someone took the time and effort to actually remove the entire monument.

All I am asking is if you are sure that the disk is totally gone.

 

Matt

[Bill93]

A disk that is set flush with the ground often gets covered up by natural deposition or as more likely in this case, regrading for landscaping and installing new sidewalks. So I echo the thought that you would need to probe pretty deeply, or else do the level survey from some other known mark, to show that it wasn't just covered up.

[Z15]

We typically set those at least 5 ft in length (NGS Specs) and often set an underground mark. I don't know if this one has it though, I worked in another part of state, some 500 miles distant. They might be well aware of the marks demise or would like to know of it.

 

fyi

The state advisor in Michigan has his office in the Design Survey office in the State Transportation building in Lansing and is funded by a cooperative effort between the MDOT and NGS.

Edited September 26, 2004 by elcamino