[Proj] Slightly off-topic: The phantom island that is real
Mikael Rittri
Mikael.Rittri at carmenta.com
Thu Nov 29 07:08:41 EST 2012
Aha! It must be Captain Nemo's submarine Nautilus that surfaces
now and then. Jules Verne wrote about it in 1870, so it could
appear on 19th century maps!
Okay, so it is supposed to be only 70 meters long, but what's
a few of orders of magnitude among friends?
Mikael
-----Original Message-----
From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of support.mn at elisanet.fi
Sent: Wednesday, November 28, 2012 1:32 PM
To: PROJ.4 and general Projections Discussions
Subject: Re: [Proj] Slightly off-topic: The phantom island that is real
Hehe,
the phantom military vessel theory is not totally excluded..
if there is a place that is 1400 m deep water when
a research vessel visited it and old maps show
whatever and so do new.. and nobody can 100%
confirm anything.. so I would put a military vessel
of what ever size as one of the possibilities..
until better researched
regards: Janne.
------------------------------------------------------------------------
Daniel Strebe [strebe at aol.com] kirjoitti:
> At 30_km x 6_km that would be one mighty aircraft carrier! Also, it shows up
> on 19th century maps, same shape, which would makes it a doubly impressive
> aircraft carrier.
>
> Best,
> --daan
>
> -----Original message-----
> From: support.mn at elisanet.fi
> To: proj at lists.maptools.org
> Sent: Tue, Nov 27, 2012 13:17:34 GMT+00:00
> Subject: Re: [Proj] Slightly off-topic: The phantom island that is real
>
> Hello,
>
> well it might also be a hiding place for a military vessel ..
> for example a large aircratft carrier ..
> that would explain the reason why it time
> to time disappears and comes back?
>
> at least the "sand island" top view is very
> much like an aircraft carrier? ;)
>
> http://static.ddmcdn.com/gif/aircraft-carrier-top-view.gif
>
> regards: Janne.
>
> -----------------------------------------------------------------------------
> -----------------------
>
> strebe at aol.com kirjoitti:
> >
> > Joaquim: Thank you for the explanation. But I think all you have done is
> confirm that the region is probably a large sand bar, sometimes submerged or
> partially submerged. There seems to be two reasons data is so sparse there:
> frequent cloud cover hindering remote sensing, and very shallow water that
> makes soundings by ship impossible.
> >
> > Here is a representative sample of MODIS data that I culled from USGSs
> Global Visualization Viewer:
> > http://commons.wikimedia.org/wiki/File:MODIS-MCD43A4-02-2004.png
> >
> > The particular MODIS data set is MCD43A4 (MODIS/Terra+Aqua Nadir
> BRDF-Adjusted Reflectance 16-Day L3 Global 500m SIN Grid). If you cycle
> through the months and years, you can clearly see that MODIS usually sees
> something there but sometimes does not. That means (to me) that sometimes
> the sand bar is submerged too far for the satellite to detect it but usually
> is shallow enough to yield a signal. None of the data are consistent with
> deep water.
> >
> > Regards,
> > daan Strebe
> >
> >
> >
> >
> > -----Original Message-----
> > From: J. Luis <jmfluis at gmail.com>
> > To: strebe <strebe at aol.com>
> > Sent: Sat, Nov 24, 2012 6:36 am
> > Subject: Re: [Proj] Slightly off-topic: The phantom island that is real
> >
> >
> > Daan
> >
> > Although we never phrased it out in those mails, it's quite obvious
> that what appears to an island in the SRTM+ is nothing but an
> interpolation artifact introduced by a constrain imposed the coastline
> itself. Notice how close the coastline and the 1 m meter contour lines
> are. Furthermore the maximum height in the SRTM+ data is 1m meter, which
> is obviously very suspicious. I'll add it also that the 'Walter' that
> appears in one of those mails is Walter Smith from the Smith & Sandwell
> bathymetry.
> >
> > HOWEVER, that does not rule out the possibility that the island
> exists. Only says that there is no reliable data to constrain the grid
> construction at that location. The 1400 m difference also puzzled me a
> bit and moved by your mail I searched also the MODIS data for Sea Surface
> Temperature ... and the mystery continues MODIS does not seam to find
> water over there. See the image that I posted in GMT mailing list.
> >
> >
> https://listserv.hawaii.edu/cgi-bin/wa?A2=ind1211&L=GMT-HELP&D=0&T=0&P=116217
>
> >
> > Regrads
> >
> > Joaquim
> >
> >
> > I dont follow your assertion. The e-mail you cite states the
> island DOES appear in GTOPO30 and SRM30+. I see the same
> thing. When I look at the raw values in SRTM30 Plus, the
> entire area of the island consists of sea-level DEM
> values. Plus, NASA Blue Marble satellite imagery
> clearly shows shallow water over the entire 30_km x
> 6_km area that is called Sandy Island on
> innumerable maps.
> >
> > Whether or not there is an island there (as opposed to a
> barely submerged sandbar) is perhaps open to
> debate or depends on the tides. But the crew of the
> research vessel is claiming 1,400_m soundings,
> which just does
> not coincide with that area at all
> >
> >
> >
> >
> > Regards,
> > daan Strebe
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: J. Luis <jmfluis at gmail.com>
> > To: PROJ.4 and general Projections Discussions
> <proj at lists.maptools.org>
> > Cc: strebe <strebe at aol.com>
> > Sent: Fri, Nov 23, 2012 6:40 pm
> > Subject: Re: [Proj] Slightly off-topic: The phantom island
> that is real
> >
> >
> > We discussed that on the GMT list too and no, the island
> does NOT exist in the SRTM+ or GTOPO30 series
> >
> > See for example
> >
> https://listserv.hawaii.edu/cgi-bin/wa?A2=ind1211&L=GMT-HELP&D=0&T=0&P=107015
>
> >
> > Joaquim
> >
> >
> > The crew of a research ship claims to have undiscovered a
> large island in the South Pacifics Coral Sea near New
> Caledonia, called Sandy Island. The news feeds have
> picked up on this and its making its way around the
> geeksphere with great rapidity. Here is an example article:
> >
> http://phys.org/news/2012-11-aussie-scientists-un-discover-pacific-islandhtm
> l
> >
> > However, it is quite clear from satellite imagery and
> multiple data sources that the island in fact
> exists, though possibly it is a barely submerged sandbar.
> Yet the crew claims depths there are around 1,400 meters
> >
> > Obviously the ship was not where they say it was. The
> question is, how did the crew of this research vessel
> convince themselves they were sailing in the same
> area? I dont think a datum mismatch can account for this,
> given the size of the sandbar.
> >
> > I have started a thread here:
> >
> http://mapthematics.com/forums/viewtopic.php?f=10&t=469
> >
> > Enjoy!
> > daan Strebe
> >
> >
> >
> >
> >
> >
> >
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> >
> >
> >
> >
> >
> >
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