Badwater's True Lowest Point (2013) - Printable Version +- Death Valley (https://dv.netllama.us/dv) +-- Forum: Death Valley (https://dv.netllama.us/dv/forumdisplay.php?fid=1) +--- Forum: Death Valley Environment (https://dv.netllama.us/dv/forumdisplay.php?fid=6) +--- Thread: Badwater's True Lowest Point (2013) (/showthread.php?tid=25988)

Badwater's True Lowest Point (2013) - GowerGulch42 - 2021-12-31 There's another thread discussing using lidar (light detection and ranging) to determine more accurate elevations for high mountain peaks. Someone also mentioned that application being used to find the true low point of Badwater Basin, so I did. Here's how. There is no high-resolution lidar data for Badwater Basin. There is some elsewhere in Death Valley, along the Furnace Creek Fault and the Panamint-Saline Valley Faults, but none of those cover the salt flats out from the parking lot. So I got the next-best thing (or rather, the only thing). The highest-resolution elevation model for Badwater Basin is a 2013 1/3 arc-second radar map. This is made by satellites, so it's much lower resolution than can be gotten from an aircraft. Since Badwater Basin is a low-relief surface, this is OK since the lowest point is likely to be a flat area rather than a single point. The ground resolution of 1/3 arc-second is 10 meters, a little over 32 feet.  I downloaded this digital elevation model (DEM) from The National Map, the spatial data repository managed by the USGS. It covers most of the basin between Salt Creek and Foundry Canyon, so that's all the important low area. I first clipped out everything above sea level - this reduces the range of elevations from well over 6,000 feet to only 282 feet. This makes the next analysis much easier and faster.  I generated 5 ft contours for the whole salt pan below sea level, and then created more 1 ft contours for the salt flat itself below -279 feet, the elevation of the boardwalk. I didn't save a screenshot of what that map looked like, so I'll have to redo it and post later. I found that the lowest 2 feet, ranging -280 to -282, covers a huge area of the playa. The old coordinates at [ 36.241921°, -116.825441° ] fall squarely at -281 feet. The contours highlighted an area about 1.4 miles to the south of all the land below -282. Here they are in relation to one another: This lowest - low area is about 0.4 acres, about 220 feet by 94 feet, in size. It is also much closer to the boardwalk than the previous point. It is a mere 1.9 miles straight out from the trodden area! The lowest point on the DEM is located within this area at [  36.233001°, -116.802648° ].   The playa is, however, a dynamic place. This true low point may move around year-to-year, or even season-to-season. It's nearly impossible to say how far it might move without newer or more frequent data of this type, and I'll jump right on it when it gets created! So I present to you… the 2013 True Lowest Point per Satellite Radar Mapping of Badwater Basin! RE: Badwater's True Lowest Point (2013) - netllama - 2021-12-31 This is so damn cool. Thanks! RE: Badwater's True Lowest Point (2013) - MojaveGeek - 2022-01-02 Great analysis! RE: Badwater's True Lowest Point (2013) - DAW89446 - 2022-01-03 Thank you for your efforts. I also appreciate your clear presentation. RE: Badwater's True Lowest Point (2013) - ski3pin - 2022-01-03 Excellent work and nicely presented! RE: Badwater's True Lowest Point (2013) - GowerGulch42 - 2022-01-05 I have *tentative* plans to visit the park in March. If the playa is dry and weather favorable… maybe, just maybe, I'll voyage out here! Much shorter hike than the old spot given in Digonnett and elsewhere. RE: Badwater's True Lowest Point (2013) - David_Bricker - 2022-01-11 Very interesting, and thank you for sharing and doing all this work. Not wanting to be a pessimist, but is is possible NPS shows a location much further away from the boardwalk, to discourage unprepared tourists from trying to walk to it? After all, it's "only" 2 miles. What could possibly go wrong (in the summer, with one bottle of water)? David Bricker / SYR RE: Badwater's True Lowest Point (2013) - GowerGulch42 - 2022-01-11 Probably not. I have never seen an NPS publication advertising the "true" location of the lowest point, but that's not to say it doesn't exist. Ergo, they don't make any effort to "idiot-proof" Badwater Basin apart from making the photogenic sign at a convenient and accessible location. The coordinates I have seen have all been posted/written by third parties or the USGS. RE: Badwater's True Lowest Point (2013) - DAW89446 - 2022-01-12 It’s already established that the true lowest point is going to move about a bit due to the nature of the salt flat, so publishing that would be irrelevant in time. And, it seems, that the lowest point is by mere inches in many cases, spread out over a wide area. RE: Badwater's True Lowest Point (2013) - DeathValleyDazed - 2022-01-12 The lowest spot may move around even more than we think due to "earth crust tides" caused by the Moon and to a smaller degree by our Sun. I wonder if anyone has attempted to measure crust tides around Death Valley? https://science.howstuffworks.com/environmental/earth/geology/rising-rock-earths-crust-has-its-own-tides.htm