Jump to content
Sign in to follow this  
Followers 1
m&h

Phantom Reset?

Recommended Posts

In locating and logging GU3965, JEFFERS, in Carmel, California, we noticed something odd in the datasheet. The mark was monumented in 1932, and recovered in 1932, 1949, and 1968. In the 1932 station description and the 1949 recovery note, respectively, the station is described as being set in OUTCROPPING BEDROCK (1932) or A NATURAL BOULDER (1949). In 1968 it is described as being set in THE TOP OF A 7-INCH SQUARE CONCRETE POST PROJECTING 0.3 FOOT ABOVE THE GROUND.

 

The present mark, which is indeed set in the top of a concrete monument, bears no stamping that indicates a reset. The datasheet makes the shift without comment. Does somebody have a good idea about what went on here? Many thanks.

Share this post


Link to post

That certainly is a strange one!

 

I notice that the reference marks (DA7728 and DA7729) are "missing in action".

 

A mark 0.2 miles away, set in 1875, also is missing.

 

This area may be haunted, or in use by extra-terr. entities. (grin)

 

-Paul-

Share this post


Link to post

PFF, where in the logs did you see that RMs were missing? One log on GC does have a picture (unreadable) claimed to be a RM.

 

m&h did you try to measure from the RM to verify that the position made sense? Did your GPS say it was at the adjusted coordinates within the indicated accuracy at the time?

 

I wonder if the NGS log is missing an entry where they did go out and set a concrete post over the hole in bedrock because the disk was coming loose and in order to keep the disk above ground.

 

It seems like I've seen another case where we thought a triangulation station disk was reset without being restamped. Since it was done over the exact same spot to the best of their ability (and within the tolerance for the class of mark) maybe they didn't feel it needed to be marked RESET. The vertical control disks that are marked RESET are almost always in a different location and the elevation uncertainty is usually significantly greater than that of the original.

Share this post


Link to post

Bill93, we did not find either of ther RMs, though the log previous to ours does have one reported. However, we are confident of this mark, by its stamping and description; the distances from street centerlines and existing buildings are right.

 

The possibility of a "silent reset" seems likely to us.

Share this post


Link to post

Old thread revisited, as we have revisited the station and located RM1, which we can now verify is the same mark in the unreadable photo posted by TrekkinD exactly four years ago. We could not find RM2, which appears to have fallen victim to some retaining wall construction along the rear of the house (the side facing Scenic Road). We posted a note at GU3965, with a couple of pictures. This doesn't solve the question of the altered setting, but it makes us feel better.

Share this post


Link to post

Congrats on the find! And it is cool that they may have named the station after Robinson Jeffers.

 

The history of the original mark certainly is mysterious. The resets I've seen have all, to the best of my recollection, been new disks, stamped with the date of the reset. Has anyone else encountered a situation where someone apparently reset the original disk? Maybe it's common and I just haven't run across it myself.

 

Patty

Share this post


Link to post

Well, we went back a third and final time and uncovered RM2 a little less than five feet toward the street from the retaining wall. It was under about three inches of duff and pine (cypress? fir? anyway) needles. So both marks are there and good.

Share this post


Link to post
Well, we went back a third and final time and uncovered RM2 a little less than five feet toward the street from the retaining wall.

Wow, that's determination! Congratulations!

 

Patty

Share this post


Link to post

Searching this forum for a slightly different subject (see below) and happened upon this one.

 

In the last two weeks I have come across several marks that I suspect have had a NO HISTORY RESET.

 

This one Z 122 1935

 

97408530-8698-4e5b-aa77-161e8a6593e7.jpg

 

seems to be plumb but the others are tilted a bit. The stamping on all is not properly oriented. I logged them

with a note and generally will NGS recover them as FOUND, with a cautionary note.

 

The other subject:

Can anyone tell me the significance of the added stamping 'ASA 1470' - again NO HISTORY in the DS - on this Tri station?

 

11c1fb28-0dd5-48a2-a2f0-3e28e26098cd.jpg

 

SASABE

 

Four TRI's and one BM were found in the Alar Valley, Pima Co AZ this week with this ASA # ranging from 1470 to 1480.

 

Thanks, kayakbird

Edited by kayakbird

Share this post


Link to post

I have no specific details, but I do seem to recall a few instances of the same type of thing on marks I have recovered.

I haven't been there, but DU2086 seems to have been reset with a bronze disk in place of the original aluminum.

No notation of a reset.

Share this post


Link to post

I have no specific details, but I do seem to recall a few instances of the same type of thing on marks I have recovered.

I haven't been there, but DU2086 seems to have been reset with a bronze disk in place of the original aluminum.

No notation of a reset.

 

SUPERSTITION

02d5402e-aa04-4c52-965a-71740d8f8aa0.jpg

 

DU2086'STAMPED 1910 SUPERSTITION RESET 1965 U.S.C.G.S 1946 - from BA's excellent 2009 log & recovery. I guess that the disk constitutes 'hard copy paperwork' for a USGS RESET.

 

I should have made clear that the ones I have been seeing are full concrete post RESET's. MEL

Share this post


Link to post

The other subject:

Can anyone tell me the significance of the added stamping 'ASA 1470' - again NO HISTORY in the DS - on this Tri station?

 

11c1fb28-0dd5-48a2-a2f0-3e28e26098cd.jpg

 

SASABE

 

Four TRI's and one BM were found in the Alar Valley, Pima Co AZ this week with this ASA # ranging from 1470 to 1480.

 

Thanks, kayakbird.

 

 

I think I found a clue! CG0184'MARK IS NOW STAMPED 'ASA 2195 U 80 1934 1994' (THANK YOU ARMY) MEL

 

Fresh photo of U 80 added. MEL

 

278ac357-4c2b-45d8-bdfc-d2abc64bb774.jpg

Edited by kayakbird

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  
Followers 1

×
×
  • Create New...