Giant ‘Gravity Hole’ in the Ocean May Be the Ghost of an Ancient Sea
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https://www.scientificamerican.com/article/giant-gravity-hole-in-the-ocean-may-be-the-ghost-of-an-ancient-sea1/ <-- shared technical media article
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https://doi.org/10.1029/2022GL102694 <-- shared 2023 paper
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https://oceanservice.noaa.gov/facts/geoid.html <-- technical description of a geoid
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[theories abound]
"... KEY POINTS
• Employing time dependent global mantle convection models since the Cretaceous. [the authors] simulate the origin of the enigmatic Indian Ocean geoid low
• Plumes forming along the edges of the African Large Low Shear Velocity province (LLSVP) control the regional geoid in the Indian Ocean
• These plumes, in turn are generated by lower mantle Tethyan slabs that perturb the African LLSVP…”
#GIS #spatial #mapping #geoid #gravity #mapping #global #remotesensing #plume #ocean #ancientocean #gravityhole #geophysics #IndianOcean #geology #structuralgeology #crust #mantle #core #high #low #potsdamgravitypotato #IOGL #tomography #model #modeling #plate #tectonicplate #Tethys #slab #mantleplume #LLSVP #AfricanLargeLowShearVelocity

One day One map: Earth's shape

Source: Mad Maps, 2019
#geoid #cartography #maps

We continue our collaboration with #Gigafact, another non-profit with a specialized mission: provide impoverished newsrooms with brief, plain language #ClimateMythDebunkings ready to drop into news coverage.

Here's the latest output, covering #SeaLevelRise.

Sea level is fairly easy fodder for creating confusion; the behavior of sea level varies broadly depending on where on our #geoid one measures. A noisy signal but with a clear broad trend.

https://skepticalscience.com/fact-brief-sealevel.html?utm-source=,mastodon&utm-campaign=socialnetworks&utm-term=sks

Fact brief - Is sea level rise exaggerated?

Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.

Skeptical Science
Our Very Strange Search for “Sea Level”

Brooke Jarvis considers the history behind the search for sea level, as described in a new book by Wilko Graf von Hardenberg, and probes what it tells us about science, global warming, and life on our changeable planet.

The New Yorker
@BKG
Wieder was gelernt.
Aber nicht ganz verstanden: liegt's am #Geoid, daß der mittlere #Meeresspiegel der Adria (Pegel Triest) so unterschiedlich ist?
Und: werden mit steigendem Meeresspiegel die Berge immer "niedriger" (abgesehen von Eriosion und Tektonik)?
Moving mountains: reevaluating the elevations of Colorado mountain summits using modern geodetic techniques - Journal of Geodesy

One of the most challenging environments for accurate geoid models is in high, rugged mountain areas. Orthometric heights derived from GNSS and a geoid model can easily have errors at the decimeter level. To investigate the effect of geoid model variability on the elevations of peaks in high, rugged mountain areas, this paper is focused on the “Fourteeners” of Colorado, USA (a group of about 60 peaks that are above 14,000 feet = 4267.2 m). Airborne LiDAR data are used to determine geometric (ellipsoidal) heights, which first requires removing a hybrid geoid model, as the LiDAR data is originally provided as orthometric heights. We quantify a significant improvement when using these derived ellipsoidal heights compared with the original orthometric heights: from ± 0.074 to ± 0.054 m (RMSE), an improvement of 28%. Next, a mean geoid model is determined with a relative accuracy of ± 0.06 to 0.08 m and used as a “stand in” realization of the future, official geopotential datum of the USA, NAPGD2022. Using the LiDAR ellipsoidal heights and geoid model, elevations (and uncertainties) for each of the Fourteener summits are determined and found to be, on average, 1.6 m lower than currently published values. This is a much larger change than the 0.5 m decrease expected from the new datum shift alone. The bulk of the difference is due to the original treatments of the vertical angle, triangulation data. A reanalysis of 32 of the 60 peaks shows that the historic data were indeed too high by about 1.0 m or more. Ultimately, no peak falls below the 14,000-foot level nor are any peaks elevated above this level.

SpringerLink
Genesis

Word Search Puzzle 44

Word List : #bedote #unrushed #mowana #toadess #nanoword #spookish #azimene #doven #bulletin #manure #libber #behenic #geoid #lengths #haick #maltable #crucian #rsvp

Kara Finance
The Mystery of the World’s Largest and Deepest Gravity Hole
The sea level here is hundreds of feet lower than the rest of the ocean.
https://www.atlasobscura.com/articles/gravity-hole-indian-ocean #IndianOcean #GravityHole #gravitational #anomaly #geoid #low
The Mystery of the World’s Largest and Deepest Gravity Hole

The sea level here is hundreds of feet lower than the rest of the ocean.

Atlas Obscura
The Mystery of the World’s Largest and Deepest Gravity Hole
The sea level here is hundreds of feet lower than the rest of the ocean.
https://www.atlasobscura.com/articles/gravity-hole-indian-ocean #IndianOcean #GravityHole #gravitational #anomaly #geoid #low
The Mystery of the World’s Largest and Deepest Gravity Hole

The sea level here is hundreds of feet lower than the rest of the ocean.

Atlas Obscura