[Geysers] Mapping Help

[Steven Miller]

I do remember those trips where David led us into some areas. Thanks for your help David.
 
While David was off exploring, myself and the student volunteers, used the non-sub meter GPS units of that time to map the thermal features.  We collected 120 GPS data points for each thermal feature. All GPS points were taken as close to each thermal feature as was possible, with safety always the first concern and not damaging the thermal feature the next. Some features are too hazardous to stand at the edge of or could be damaged, we all know this. For those, we off set the GPS point via compass direction to compensate. 
 
Those GPS points, after differential correction, which was required at that time, are very accurate.  Of course they are not accurate within a few millimeters. For that we would have needed to use a transit and started from benchmarks. Then of course the features come in all shapes and sizes and like to change as they please. 
 
 “many of the coordinates that year were only taken within roughly the same long-distance dialing area as the feature being mapped.” Anyone who watched and understood the mapping process would understand the complexity of trying to “map” 5 or 6 fist size holes all within a couple of feet of each other or 4 larger pools within a couple feet.  Also the issues of trying to map two large pools that are within a few feet of each other when the only safe and respectful approach was between the two pools. We did not just map the interesting features or the geysers; we mapped all of the features. 
 
Much is not understood about this process. It is not understood that a satellite orbiting out of range could make a difference of a few inches or more in the mapping results, or the cluster of trees that is blocking a satellite or walking closer to a hill side. 
Even translating from UTMs to lat/long can induce a bit of an error. 
 
“In an area that has a few geysers all within a few feet”……………..”(I have had cases where the marker was pretty much equidistant from 3 holes and I had no idea which one it belonged to).”.  Will, some features may have been mapped as one. This depends on what and where. Please review the notes for the location if available.
An example from Geyser Creek, “~20 pools circular ranging from .10 to 1.5m wide.” Mapping 20 small pools so close is not feasible nor is standing next to or over each for the time required to map. 
 
I hope this helps.
Steven Miller


"Life is pleasant. Death is Peaceful. It is the transtion that's Troublesome." -Issac Asimov
 



Date: Sun, 10 Nov 2013 20:45:22 -0600
From: david.schwarz at alumni.duke.edu
To: geysers at lists.wallawalla.edu
Subject: Re: [Geysers] Mapping Help


I can answer that one, at least based on the first year the project was taking coordinates for the Firehole Geyser Basins.  The SCA techs that year, especially early on, were much shyer about getting close to the features than they needed to be, and no policy had been laid out by project management on where to take coordinates for large or genuinely unapproachable features.
As a result, many of the coordinates that year were only taken within roughly the same long-distance dialing area as the feature being mapped.  Obviously, it doesn't matter how accurately the equipment pinpoints your location if you're not particularly close to what you're trying to map.
It also wouldn't surprise me if some mislabeling or shuffling happened, especially in dense areas like Geyser Creek or Geyser Hill.
David Schwarz
On Nov 10, 2013 8:31 PM, "Udo Freund" <udofreund317 at gmail.com> wrote:


Forgot to mention that Yellowstone has had some earthquakes that might cause things to actually move around over the course of several years since GIS surveys were done.
Thanks,
Udo Freund
On Nov 9, 2013 5:21 PM, "Will Boekel" <wolveslax65 at comcast.net> wrote:





Scott,
 
Thanks for the advice about using the RCN data. I have been using that resource and it has been very helpful most of the time. However many of the coordinates in their database are a bit off and most of the pictures are of the geyser’s vent and not a location photo. In an area that has a few geysers all within a few feet of each other it is sometimes hard to figure out where the slightly off RCN marker belongs (I have had cases where the marker was pretty much equidistant from 3 holes and I had no idea which one it belonged to).
 
Thank you for the help,
 
Will Boekel
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