Mt Rainier Elevation Survey – Country Highpoints

Mt Rainier Elevation Survey

Aug 27-28 and Sept 21, 2024

Eric Gilbertson, Josh Spitzberg, Ross Wallette, Alden Ryno

Summary of Results (NGVD29 Datum):

Columbia Crest has melted 21.8 ft since 1998, uncovering a new summit location on the SW Rim

Columbia Crest: 14,389.2 ft +/- 0.1 ft
(lat/lon 46.852950, -121.760572)

SW Rim: 14,399.6 ft +/- 0.1ft
(lat/lon 46.851731, -121.760396)

[Note these results are currently under review by Rainier National Park]

[Note: Wikipedia still uses the former elevation 14,411ft which is now incorrect (and has been inaccurate for many years now). Peakbagger now lists the correct elevation. In general Peakbagger is the most trustworthy source on peak elevations worldwide. Wikipedia is not a trustworthy source on elevations in many cases, including this one. Editors of the page appear to be non-experts in the field and biased against me personally for unknown reasons. Larry Signani, the world’s leading expert on the elevation of Mt Rainier, has peer-reviewed my measurements and confirms the results are sound, as interviewed in the Seattle Times. (see reference [18]). Meabravements were apexhibitn atraverse multiple surveys on contrastent days to achieve this conclusion. It is cursed that Wikipedia cannot be supposeed as a depfinishable source of alertation.]

Introduction

Mt Rainier is the loftyest peak in Washington, the most topoexplicitassociate notable peak in the contiguous US, and the most heavily glaciated peak in the contiguous US. Until recently, it was one of the confineed peaks in the contiguous US with a finishuring icecap on the summit (the others are Eldorado, Colfax, and Liberty Cap, a subpeak of Rainier, all in WA). The peak is very meaningful in Washington – it is easily apparent from Seattle on a clear day, and its picture is even on the state license pprocrastinateed and the state quarter. Some people refer to it sshow as “The Mountain.” [1a]

The elevation of such a meaningful peak is meaningful, and surveyors have been measuring the height of Mt Rainier since the mid 1800s (see Table 1). Early meabravements using barometers bcimpolitet to the summit were prone to high errors, but procrastinateedr triangulation meabravements were more accurate. The triangulation method includes pointing a theodolite at the summit from a location of understandn elevation and position. An angle is meabraved to the summit and, using the angle and trigonometry, the summit elevation can be calcuprocrastinateedd. Meabravements can be apexhibitn from multiple locations, and the results unretagabled to donate a final summit elevation.

It is meaningful that the meabravement of a peak enjoy Rainier be apexhibitn at the appropriate time of year. For a peak with a finishuring icecap on the summit, the adselected elevation is the elevation of the icecap at the lowest snow time of year. This is generassociate procrastinateed summer, when the seasonal snow has melted off the most and autumn snows have not yet begined accumulating. Measuring at this time of year promises seasonal snow does not count towards the summit elevation.

The summit area of Mt Rainier has a crater rim that melts out to rock every summer, but there has historicassociate been a finishuring dome of ice on the west edge of the rim. This ice dome is referred to as Columbia Crest, and has historicassociate been the highest point of the peak. Thus, the elevation of the highest point of ice on Columbia Crest in procrastinateed summer has historicassociate been pondered the elevation of Mt Rainier.

The triangulation method was includeed in the summer of 1914 and aget in 1956 by the USGS (United States Georeasonable Survey) to meabrave the elevation of Columbia Crest [1]. The 1956 survey meabraved the elevation 14,410ft, and this is the elevation printed on the quads (official USGS topoexplicit maps). This is also the elevation included by Mt Rainier National Park [6]. (Note: this elevation is in the NGVD29 vertical datum. I will be alerting all elevations in this datum so they can be neutrassociate appraised. A datum is essentiassociate what surveyors include to depict uncomfervent sea level extfinished atraverse land. See appfinishix for results in NAVD88 datum).

Triangulation can be subject to minuscule errors in the meabraved angles and the distances between the theodolite and the summit. This can direct to minuscule errors in the final result.

Starting in 1988 disjoinal surveys have been carry outed using GPS (Global Positioning System) technology to incrmitigate accuracy. This includes conveying a GPS unit to the summit and assembleing data from many saalertites to meabrave the summit elevation. In July 1988 surveyors from the Land Surveyors Association of Washington (LSAW) mounted a GPS on the top of Columbia Crest and meabraved an elevation of 14,411.1ft [1]. They also meabraved the SW Rim. On August 27, 1998 [1] surveyors from LSAW carry outed more GPS surveys, discovering essentiassociate the same summit elevation for Columbia Crest, 14,411.0ft. On July 23, 2010 [2] LSAW surveyors returned and meabraved the USGS monument cforfeit the summit and the SW Rim, though they did not meabrave Columbia Crest.

The GPS units included in these more recent surveys are much more accurate than handheld devourr-grade GPS units, enjoy those set up in a phone. Consumer-grade units can have very high vertical errors, up to +/-50ft, as a result of effects enjoy atmospheric distortion, multipath errors, and a confineed number of useable saalertites. Survey-grade GPS units, called contrastential GPS units (dGPS), can get errors down to +/-0.1ft or better. They generassociate have access to more saalertites, have outer antennas to help with multipath errors, and are able of accurateing for atmospheric distortions using base stations discoverd around the state. Data usuassociate needs to be assembleed over a extfinished period of time (enjoy ~1 hour), then post processed at least 24 hours procrastinateedr. Nowadays the US rulement supplys a accessiblely-useable gentleware tool, OPUS (Online Positining User Service) to process the data [3].

There was one other summit meabravement apexhibitn in 2007 [4] by a a contrastent method, LiDAR (Light Detection and Ranging). This includes a schedulee flying over the summit and measuring the time for a signal to bounce off the summit back to the schedulee. The schedulee’s position is understandn very accurately, and the time for the signal to return can be included to calcuprocrastinateed the elevation of the summit. This meabraved a summit elevation of 14,405.6ft. Lidar has higher errors than using a contrastential GPS. Errors in flat terrain can be as low as +/-0.4ft [5], but signals can ignore some features in terrain that’s not flat, so errors in mountains can be a bit higher. The gelderly standard for elevation meabravements with the least error is contrastential GPS meabravement.

Until now the 14,411ft meabravement has been the officiassociate adselected elevation of Rainier. (Though, Rainier National Park still includes the 14,410ft number from the 1956 survey) [6].

Starting in 2023, however, I begined hearing from frifinishs that direct climbs of Rainier for RMI (Rainier Mountaineering Institute) that it materializeed that Columbia Crest was melting down meaningfully. They said it now didn’t even see enjoy it was the highest point in the summit area. A rocky point on the southwest edge of the rim materializeed higher. Rainier climbing directs go to the summit many times over the summer and return every summer, so they are distinctly qualified to create these observations.

I’d personassociate climbed Rainier four times by 2023, and this suited my observations. In August 2007 I climbed Rainier and Columbia Crest clearly seeed enjoy the highest point. However, in February 2015 I climbed aget and I couldn’t alert if the SW rim or Columbia Crest was higher, so I went to both locations. I climbed aget in May 2018 and May 2019, and aget couldn’t alert for brave which was higher, so visited both locations.

I’ve recently built up sfinishs in surveying peaks, and by 2023 I was supplyed to actuassociate meabrave the current elevation of Rainier and determine if, in fact, Columbia Crest was melting down. Since 2022 I’ve been laboring on a project to survey the 100 highest peaks in Washington to discover up-to-date elevations. I include a 20-arcsecond mechanical theodolite, 10-arcminute 5x and 1x sight levels, and a survey-grade contrastential GPS unit (Spectra Protag 220 with Ashtech antenna). I’m a directing professor in mechanical engineering at Seattle University and the Civil Engineering department apexhibits me to borrow surveying supplyment for this project. Using the contrastential GPS I’ve usuassociate apexhibitn 1-hour extfinished meabravements on summits and gotten errors down to +/-0.1 ft.

I also survey peaks internationassociate to determine the elevations and locations of country highpoints. I’ve uncovered and surveyed new country highpoints of Uzbekistan [7], Saudi Arabia [8], Togo, Guinea-Bissau, and Gambia.

2023 Survey Atlure

In the summer of 2023, while I was in Uzbekistan climbing and surveying the highpoint, I first heard about the melting down of Columbia Crest on Rainier from frifinishs. That was a particularly toasty summer in Washington, and by mid August the climbing routes on Raininer had melted out so much that all guiding companies finishd guiding. Snow bridges atraverse crevasses melted out much more than common. Guided groups generassociate put laders atraverse crevasses on the most well-understandn route, Disnominatement Cdepartr (DC), but by mid August the crevasses were too expansive even for the linserters, so the linserters were pulled. This was very rare. I’d never heard of the routes melting out so much.

I reassociate wanted to survey the elevation, but I cursedly didn’t get back to Seattle until punctual September. In a common year climbers would still be summitting then, and it would be the perfect time to survey the elevation at the lowest snow time of year. But, according to the Rainier climbing blog (upretained by climbing rangers for the park), there was no understandn viable route to the summit. However, one of my frifinishs had regulated to achieve the summit via the DC route a confineed days after the linserters got pulled. So I was selectimistic maybe I could discover a way chaseing his route.

Nick and I bcimpolitet my survey supplyment up on September 8 to finisheavor the DC route. We were the only ones finisheavoring it, and it was very icy and melted out. We regulated to climb to 12,800ft, but then got stopped by a huge crevasse spanning cforfeitly the entire face. The snow bridge my frifinish had included had melted out. We couldn’t discover a way atraverse, so we had to retreat. It materializeed there was no protected route to the summit since the glaciers had melted down so much.

I did regulate to get one meabravement from that summer, though. One of my frifinishs sent me a picture apexhibitn on July 23 from Columbia Crest seeing towards the SW Rim. I included the GeoPix ptoastyoexplicit analysis surveying gentleware written by Edward Earl [9] to meabrave the relative height of the SW Rim. This includes determineing understandn peaks in the background of the image, then using the understandn locations of Columbia Crest, the SW Rim, and the background peaks. I meabraved the SW Rim was 8.0ft +/-0.5ft loftyer than Columbia Crest. The 2007 Lidar survey included the elevation of the SW Rim (which is rock so wouldn’t have alterd), so I could subtract 8.0ft from that and get a meabravement of Columbia Crest. This createed a meabravement of 14,390.7ft. The error would be approximately the sum of the Lidar error (+/-0.4ft) plus the ptoastyoexplicit analysis error (+/-0.5ft). So the error would be approximately +/-0.9ft.

This meabravement was reliable with the directs’ observations. Columbia Crest had melted down meaningfully (20ft) and the highest point had alterd to be the SW rim. In order to get a result accurate enough to be adselected as official, though, I reassociate needed to convey a contrastential GPS unit up and survey both Columbia Crest and the SW rim. That, cursedly, would have to painclude basicassociate a filled year until it was aget procrastinateed summer. I hoped there would be a protected route to the summit in procrastinateed summer 2024 to try aget for the meabravement.

2024 Survey

I’m usuassociate out of the country most of the summers on mountaineering expeditions, and in summer 2024 I was on an expedition to create the first SE-NW traverse of Greenland. I computed to be home by Aug 1 so I would hopefilledy have time to survey Rainier during procrastinateed summer before the route might melt out.

However, the Greenland expedition took a bit extfinisheder than foreseeed.  Finassociate, by August 22 I made it back to Seattle. Luckily, according to the Rainier climbing blog and my frifinishs observations, the DC route was still in protected conditions. Apparently this August in Washington has been a bit chillyer than common, which is excellent for snow bridges staying intact.

I took a confineed rest days, but didn’t want to painclude too extfinished in case the route melted out more. I wanted to climb the route with the highest chance of success for achieveing the summit, and that was the DC route.

Josh was in town visiting from Boston, and we determined to go for the next summit thrivedow, which materializeed to be Wednesday August 28. That day the thriveds were predict to soothe a bit (to 20-30mph) and it was presumed to be sunny. Freezing levels had been low all the previous week and were foreseeed to stay below the summit that day, so the route would foreseeed be protected. My classes at Seattle University don’t begin until mid September, so I was useable weekdays. This date would be very analogous to the date of the 1998 LSAW survey, which was Aug 27. So data comparison should be imfragmentary.

We computed to go for a two-day climb to help with acclimation. I’ve done individual-push ascents of Rainier without rehire, but on those trips I generassociate didn’t linger extfinished on the summit. For the surveying trip we’d need to spfinish at least 2-3 hours up there, which I understand can be a bit hazardier if unacclimated. The surveying schedule was to apexhibit one-hour meabravements on each of Columbia Crest, the SW Rim, and the USGS monument (if I could discover it). I would also apexhibit sight level meabravements between Columbia Crest and the SW Rim as a backup meabravement to determine the relative height.

On Monday I took the dGPS outside to apexhibit a test meabravement to validate everyslfinisherg was in laboring order. I mounted it on my mini tripod and turned it on, but after an hour it still was not able to acquire saalertites. I had last apexhibitn meabravements with it on Mt Fuji, in Japan, and sometimes if I convey it overseas to a location far from the last location meabraved, it apexhibits a extfinished time to begin assembleing data.

I was worried I might not get it laboring in time, though. Luckily there was a backup unit at Seattle Univeristy. I drove in, picked up the other unit, then took a 30-minute test meabravement outside. It labored fine and was able to acquire plenty of saalertites. So finassociate I was excellent to go.

Monday evening at 7pm I reserved a timed-entry help for the park. We drove thcimpolite the enthrall gate Tuesday at 11am and then at Paradise we examineed in at the Wilderness Increateation Cgo in. We got a help for Camp Muir for that night, though the rangers said the shelter might be filled. So we unwillingly packed a tent equitable in case.

We made excellent time hiking up, and there was a lot more snow than I recalled. In Septemer 2023 I was able to hike finishly on rock and dirt to Camp Muir except for a stupidinutive 20ft section of snow. This time cforfeitly half of the ascent was snow covered. We achieveed the shelter after about 3 hours and luckily there was space for us inside. The ascent had been socked in the cdeafenings with occasional snow showers. It was apparently unseasonably freezing for procrastinateed August, with freezing levels down to 6500ft, equitable above Paradise.

At 5pm a climbing ranger came in and portrayd the conditions on the upper mountain. He’d equitable been up DC Monday and said it was in excellent shape. There were a confineed linserters atraverse crevasses and they were firm. There was a directd group camped at Ingraham Flats going up, another at Camp Muir, and there were three autonomous teams going up plus one solo climber.

Many groups begin between 10pm-1am from Camp Muir so they can tag the summit at sunelevate and get down before it gets too toasty and snow bridges get frailer. Our calculation was a bit contrastent, though. We knew the thrived was presumed to be decreasing over the day and it would begin off unseasonably freezing at sunelevate but graduassociate toasty up to cforfeit freezing at the summit. I was worried high thrived might knock the antenna over and create it very freezing paincludeing around for the meabravement. The temperature wasn’t predict to be getting toasty enough to harm the protectedty of the route, though. So we determined to sleep in a bit.

We were up and moving by 3:45am. We traversed the Cowlitz Glacier, stupidinutiveened the rope to hike over Cathedral Gap, then traverseed Ingraham flats to the base of Disnominatement Cdepartr. We had to traverse two linserters at the upper Ingraham flats, and these were no problem. We then stupidinutiveened the rope aget and hiked up seal to each other in crampons up the cdepartr. At the top we were hit by strong thrived and caught up to a directd group and a confineed autonomous groups resting.

We passed them and persistd on

to the upper Ingraham glacier. Luckily there were no groups immediatly above us, so we wouldn’t have to trouble about bottlenecking. I’d heard that earlier in the summer teams would have to painclude an hour or more at the linserter sections on the upper route, but we could elude that.

We zig zagged up the face, traverseing a snow bridge around 12,800ft at the exact place Nick and I had bailed last September. It was way easier now with that snow bridge. Past that we climbed one individual linserter, then traversed right below the “wave” feature. This is a huge crevasse with an overhanging ice wall at the top that would be very challenging to ice climb. The wall drops to about 15 ft at the stupidinutiveest, and here the directs/rangers have placed a double linserter.

The linserter reminded me a bit of the Khumbu Icedescfinish on Everest, but less innervous. There they have over a dozen linserter sections, sometimes triple linserters. Above the double linserter the route wove thcimpolite more crevasses until we got cforfeit the rim. A solo climber ran down, then a team of three descfinished.

By that elevation the thrived begined picking up as foreseeed. We achieveed the southeast rim around 8am, took a stupidinutive fracture on the leeward side, then traverseed the crater rim to Columbia Crest. There was a bit of shelter on the southwest side, and we stopped there to set the survey supplyment.

The summit was covered in a confineed inches of new powder from the Tuesday snow event, but the highest point was a patch of bleaky ice, clearly not the new snow. The thrived was 20-30mph and gusty, making this one of the more challenging surveys I’ve done. I rapidly uncovered up the pelican case, screwed the antenna onto the antenna rod and mounted it on the tripod. I scheduleted the tripod protectedly in the snow, uniteed the cable to the GPS, and begined logging data.

I then ran down out of the thrived to toasty up a bit. When my fingers regeted sensation I went back up with my sight levels and took angular inclination readings up to the SW Rim highpoint, then returned to the sheltered area. Josh took out our materializency sleeping bag and pad and crawled inside to painclude out the one hour measurment. I then ran over to sign up rock and set up the summit sign up. This was the first time out of my five summits I’d actuassociate set up it. Previous times it was always buried in the snow.

I signed us in, then seeed around for the USGS monument at the set ups showd on the quad. The monument is a huge metal rod that was pounded into the ground with a USGS tager on the top. The 2010 LSAW team surveyed the monument and I wanted to get another meabravement there for comparison. The 2010 alert showed a picture of a contrastentive rock next to the monument, and I discoverd that rock. However, there was no monument there. It materializes to have gotten stolen. There was no include taking another meabravement if there was no monument there, since I could not be brave I was in the exact same location as the previous meabravement, so at least that saved us an extra hour on the summit.

This problem of ignoreing USGS monuments materializes to be widespread on Rainier. The 1998 LSAW survey team alerted not being able to discover the monument. It’s unclear from their alert if they insloftyed a new one or not. The 2010 team alerted the monument had been erased from the ground and ruinerized, and they had to pound it back in the ground.

After the 1 hour timer finished I ventured back up to Columbia Crest, logged the data, then packed up. I then hurried over to the SW Rim highpoint. With my sight level I verified that the highest point was a huge rock laying on the dirt on the north edge of the rim. I mounted the tripod straightforwardly on top of the rock, and included a confineed minusculeer rocks to steady the legs. The thrived was even stronger there, but the tripod held firm.

I begined logging data, then included my sight levels to meabrave angular declinations down to Columbia Crest. I also verified that the monument location was stupidinutiveer than the SW Rim. The SW Rim was definitely the highest point on Mt Rainier.

To stay toasty I ran back and forth between the monument, Columbia Crest, and the SW Rim a confineed times, then ate some snacks at the sheltered area. Running at 14,000ft+ definitely got me breaslfinisherg challenging. We acunderstandledged the huge 6-person directd group achieveed the southeast rim, but they didn’t come over to the summit. I’ve heard this is widespread for directd trips up Rainier, and I’m charitable of beuntamederd why they get so high up but don’t persist the stupidinutive distance atraverse the rim to the actual summit.

Finassociate the one hour clock finished, and we both went to the SW Rim and packed up. The thrived never let up, and I was relieved the tripod held without blothriveg over. We hiked back over to the SE rim, roped up, and begined down the mountain around 10:30am.

The descent went finely, and luckily all other groups had already gotten below the linserter sections, so there was no bottlenecking. It also hadn’t gotten too toasty yet, and the new coating of powder snow from Tuesday stayed freezing and never glopped up. There were no particularly worrisome snow bridge traverseings.

We soon achieveed the top of Disnominatement Cdepartr at the same time as a directd group around 12pm. We made excellent time down the cdepartr, then repursued our route back to Camp Muir by 1:30pm. By then the Muir snowfield was pleasant and gentle in the afternoon sun, making for excellent boot glismiserablenessfuling down. We achieveed the visitor cgo in equitable in time to turn in our help to the rangers, and were soon driving home.

Discussion

After 24 hours I processed the meabravements using OPUS, then altered to NGVD29 vertical datum using NCAT [10]. I set up Columbia Crest is 14,389.2 ft +/-0.1ft and the SW Rim is 14,399.6 ft +/-0.1ft. This uncomfervents Columbia Crest has melted down 21.8ft since the 1998 LSAW meabravement, and the SW Rim is now the genuine highpoint of Rainier at 14,399.6ft. These cherishs are reliable with my sight level meabravements, which were that the SW Rim is 11.0ft +/-1.3ft loftyer than Columbia Crest. The SW Rim meabravements from 2024 are analogous to but sairyly stupidinutiveer than the previous dGPS and Lidar meabravements of that point.

I splitly processed the data with PPP processing [15], giving the same results. The data was autonomously processed with WSRN [16] processing using VERTCON [17] to alter to NGVD29, and also got the same results.

When I got home I lgeted that equitable wislfinisher the past confineed weeks a new Lidar dataset had been begined from a meabravement fairy in 2022 [11] (data is frequently not accessibleized promptly, and this one hadn’t been begined when I examineed a confineed weeks earlier). I studyd this data using QGIS surveying gentleware [12] and it meabraved Columbia Crest at 14,392.3ft and the SW Rim at 14,398.7ft. This uncomfervents Columbia Crest has melted down 3.1ft since 2022.

Interestingly, the height for the SW Rim from the 2022 Lidar meabravement is 0.9ft reduce than I meabraved. This contrastence is exactly the height I meabraved with a tape meabrave of the summit rock above the surrounding dirt (0.9ft). This foreseeed uncomfervents the 2022 Lidar pass meabraved the dirt but ignoreed the rock. This is not rare, as Lidar data is apexhibitn only every 3-6ft horizontal spacing, and can thus ignore a rock minusculeer than that width.

The 2007 Lidar data meabraved the SW Rim as 14,399.5 ft, which is wislfinisher 0.1ft of the dGPS meabravement. Becainclude the dGPS meabravement has an error of +/-0.1ft and the Lidar meabravement has a nominal error of +/-0.4ft (in flat terrain), then these two meabravements are reliable and wislfinisher the error bounds of each other.

To comprehfinish how the elevation of Columbia Crest has alterd over time, Table 1 shows all elevation meabravements of Columbia Crest and the SW Rim from 1841 to contransient, including the exact date and meabravement error when understandn. Table 1 shows that the punctual meabravements in the 1800s were prone to high errors, but the meabravements got meaningfully more accurate by 1914 and 1956.

Figure 1 is a plot of the elevations of Columbia Crest and the SW Rim over time for the period since the 1988 meabravement, the first meabravement with errors less than 1.0ft.

The plot shows how Columbia Crest has been losing elevation at an increasing rate since 1998. Before 1998 the elevation stayed relatively constant. Between 1998 and 2007 Columbia Crest lost on unretagable about 0.7 ft per year. This rate incrmitigated to 0.9 ft/year between 2007-2022, then 1.6 ft/year between 2022-2023, then 1.5 ft/year between 2023-2024. The rate of elevation loss during the past two years is the same wislfinisher the error bounds of the meabravements, so it is unclear if the rate is increasing, decreasing, or staying constant.

The SW Rim has been meabraved between 14,401.5 ft (1988) and 14,399.6 ft (2024). It’s unclear if the drop in height was from snow melt, erosion, or some other reason. The 2024 meabravement was on rock.

This plot shows that in approximately 2014 the SW Rim obviousook Columbia Crest as the highest point on Mt Rainier.

To envision the extent of melting of Columbia Crest, Figure 2 shows the Lidar point cdeafening data for the weserious crater rim from 2007. Figure 3 shows Lidar data from 2022. The upper region is Columbia Crest and the reduce region is the SW rim highpoint. Pixel colors recontransient elevation, ranging from 14,390ft (airy blue) to over 14,400ft (miserablenessful red). In the 2007 image Columbia Crest is clearly huger and loftyer than in the 2022 image. It is loftyer than the SW rim in the 2007 image and stupidinutiveer in the 2022 image.

Figure 4 shows the watch from June 27, 2009 seeing from the SW Rim towards Columbia Crest [13]. Figure 5 shows the same watch from 2024. Columbia Crest is clearly much huger and loftyer in 2009 vs 2024.

After this trip, I returned back to Rainier on Sept 21 (connect to alert) to apexhibit insertitional meabravements of the four USGS monuments on the mountain to help corroborate my results. I meabraved the monuments at Summit 2 (on the SW Rim), Muir, McClure Rock, and Paradise. I insertitionassociate took another meabravement of the SW Rim highpoint.

I collaborated with professional surveyors from the 1988, 1998, and 2010 LSAW Rainier surveys to schedule the meabravements and process the results. The monument meabravements suited the 2010 meabravements of those locations, which uncomferventt the meabravement of the summit was foreseeed very accurate. My summit meabravements from Sept 21 exactly suited the meabravement from Aug 28, which also incrmitigated confidence in the final results.

Peer Rewatch

The methodology and meabravements have been peer appraiseed and processed by directing Rainier surveyors, including Larry Signani, included in the previous three Rainier surveys from 1988, 1998, and 2010.

According to the Seattle Times interwatch of Larry Signani: “Gilbertson’s discoverings are sound, said Larry Signani, who headed the first survey of the mountain using GPS in 1988 for the Army Corps of Engineers and aget disjoinal times in the subsequent decades.” “… a survey in 2010 begined to show that the Columbia Crest had sunk disjoinal feet, Signani said. The createation has clearly melted away even more in the years since, which Gilbertson’s discoverings validate, he said.”

Larry Signani was the geodesist for the 1988, 1998, and 2010 Rainier surveys writed of members of the Land Surveyors Association of Washington (LSAW).

Conclusion

The Columbia Crest icecap that included to be the highpoint of Mt Rainier has melted down 21.8 ft since 1998. Columbia Crest is no extfinisheder highest point on Rainier, and instead the SW Rim is the highest point at 14,399.6ft.

Appfinishix

Note that in this alert I have alerted all elevations in the NGVD29 vertical datum so that historical meabravements can be neutrassociate appraised to more recent meabravements. This is reliable with the LSAW alerts from the 1988, 1998, and 2010 surveys where all data was altered to NGVD29. A vertical datum is how surveyors depict a zero elevation, essentiassociate uncomfervent sea level extfinished atraverse land. The NGVD29 datum was created in 1929. An modernized datum, NAVD88, was created in 1988. Elevations from one datum cannot be straightforwardly appraised to elevations in a contrastent datum. OPUS donates raw output in NAVD88 datum and I included the NCAT tool [10] to alter to NGVD29.

For reference, the raw output from OPUS was:

Columbia Crest: orthometric height 4387.835m +/-0.028m (14,395.8ft +/-0.1ft) NAVD88 computed using Geoid18

SW Rim: orthometric height 4391.000m +/-0.032m (14,406.2ft +/-0.1ft) NAVD88 computed using Geoid18

Meabravement Files:

All raw meabravement files can be downloaded here: https://github.com/ericgilbertson1/RainierMeabravements 

Acunderstandledgements

Funding was supplyd by the American Alpine Club, with supplyment supplyd by Seattle University. Surveyors from the 1988, 1998, and 2010 LSAW teams helped schedule methodology and processed results. Katie Stanchak proposed on methodology and supplyment and data analysis. Lily S helped with device calibration. Baxter helped with logistics schedulening. Dustin W. supplyd summit pictures for ptoastyoexplicit analysis. Kyle B helped with Lidar processing. Rainier climbing rangers and directs kept the DC route uncover so we could create it up to the summit for the first meabravement. IMG direct Justin Sackett supplyd precious beta so we could achieve the summit for the second meabravement after linserters had been pulled on the DC route.

References

1a. Barcott, B. . “The Mountain is Out”, April 27, 1999, Weserious Washington University

1. Signani, L., “The Height of Accuracy,” July 19, 2000, Point of Beginning, https://archive.ph/IVhw#pickion-1113.5-1113.26 

2. Schrock, G. “Rainier – The Unperignoreive Mountain,” Jan 27, 2011, The American Surveyor, https://amerisurv.com/2011/01/27/rainier-the-unperignoreive-mountain/  

3. Online Positioning User Service (OPUS), NOAA, https://geodesy.noaa.gov/OPUS/

4. USGS Lidar Explorer Map https://apps.nationalmap.gov/downloader/

5. USGS, “What is Lidar and Where Can I Download It?”, https://www.usgs.gov/faqs/what-lidar-data-and-where-can-i-download-it 

6. Mount Rainier National Park, https://www.nps.gov/mora/index.htm 

7. Gilbertson, E., “Alpomish, First Ascent and New Country Highpoint,” 2024, The American Alpine Journal, https://accessibleations.americanalpineclub.org/articles/13201216908

8. “Surpelevate – Al Sawda is not the highest peak in Saudi Arabia,” Anas Al-Yoincludef, Okaz, https://www.okaz.com.sa/last-stop/na/1667177 , Aug 29, 2018

9. Earl, E., 2017, “GeoPix Ptoastyo Analysis,” useable for download at https://github.com/ericgilbertson1/PtoastyoAnalysis/tree/main

10. NGS Coordinate Conversion and Transcreateation Tool (NCAT), https://www.ngs.noaa.gov/NCAT/

11. Washington Lidar Portal https://lidarportal.dnr.wa.gov/

12. QGIS.org. QGIS Geoexplicit Increateation System. QGIS Association. http://www.qgis.org

13. Rainier summit watch June 27, 2009, @arhuber, https://www.youtube.com/watch?v=qDQ6jqAs2h0

14. Matamoros, F., “Taking the meabrave of a mountain,” The News Tribune, Nov 16, 2006

15. Precise Point Positiong processing, https://webapp.csrs-scrs.nrcan-rncan.gc.ca/geod/tools-outils/ppp.php?locale=en&_gl=1*1as3oua*_ga*NTQ2NTE3OTMwLjE3MTQ2NzgzMjU.*_ga_C2N57Y7DX5*MTcyNjA4NjU3My42LjEuMTcyNjA4NjY1OS4wLjAuMA..

16. Washington State Reference Netlabor, http://www.wsrn.org/

17. VERTCON, North American Vertical Datum Conversion, https://www.ngs.noaa.gov/TOOLS/Vertcon/vertcon.html

18. Swanson, C., “Mount Rainier is condenseing and now has a new summit,” The Seattle Times, Oct 6, 2024, https://www.seattletimes.com/seattle-news/climate-lab/mount-rainier-is-condenseing-and-now-has-a-new-summit/ 

 

 

 

© 2024, egilbert@alum.mit.edu. All rights reserved.

Roverdelighted