How accurate was Colvin’s work

Posted in Colvin points on November 10th, 2009

I am often asked “how accurate were Colvin’s measurements”.

Well, based on the extremely small sampling that I have personally re-measured, I would say it varies from better than what is typically obtained today to god awful. The better work appears to be that in which Colvin personally performed the observations and the worst appears to be that which was performed in his absence.

A 1995 report entitled “Kinematics and Dynamics of Strain Accumulation in the Adirondacks {USGS 1434-94-G-2473, Final Report by John Beavan, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964} details the use of Colvin station marks in helping to determine the movement of the Adirondack Mountain range. A resulting un-intended conclusion of their work is found in the report as follows:

“Conclusion: The 1800’s triangulation surveys of the Adirondacks resulted in horizontal station coordinates precise to about 0.5 m (when selecting the best data available to us). The 1940’s survey resulted in precisions of 0.1-0.2 m. The 1995 GPS data gives precisions estimated at 0.01-0.02 m. The accuracies of the earlier surveys, while commendable for their time, are insufficient to detect deformation associated with the uplift of the Adirondacks.”

Jim Vianna


The Great Corner Revisited

Posted in Crew events on November 3rd, 2009

Under the direction of the Camp Clerk (Mike Webb, L.S.) students from SUNY Ranger School made a return recovery to the “Great Corner” this fall. A detailed write-up can now be downloaded from the “Past Recoveries” page.

Well done Mike,