[Proj] Slightly off-topic: The phantom island that is real
support.mn at elisanet.fi
support.mn at elisanet.fi
Thu Nov 29 06:41:30 PST 2012
Yes,
now you have the right spirit in this topic:
though Nemo must be excluded since it was a fictitious figure
by Jules Verne..
generally speaking as long as something is not excluded it
must be included ;)
Janne.
--------------------------------------------------------------------------------------
Mikael Rittri [Mikael.Rittri at carmenta.com] kirjoitti:
> 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.maptoolsorg] 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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