EVS-Islands

Eiao and Hatutu Islands FP - NASA and TerraMetrics Image Oblique View (S to N)

According to Google Earth this is Eiao and Hatutu Islands. This blurry mess is claimed by either NASA or TerraMetrics. Whoever claims it, should unclaim it. I am certain that, short of being a blurry curiosity, it serves little purpose. Now for the good stuff!

Eiao and Hatutu Islands FP - DigitalGlobe Image Oblique View (S to N)

Wow! This is what the first image should look like - a nearly cloud-free image draped over an underlying SRTM to add elevation (3D effect). This is where Google Earth "shines", taking a flat picture and creating a 3D-image. I assume, that during the construction of their global masterpiece, they included all available SRTM data. Even if the overlying image is a blurry mess, the SRTM data still provides elevation data from which GE is able to create the 3D effect.

Eiao and Hatutu Islands never looked better. I've seen a number of images, maps and charts and these DigitalGlobe images rival the very best available. I am certain the French government has highly detailed maps, charts and images of these islands as they were once considered as potential sites for nuclear testing. Thank God that ill-conceived idea was dropped!

Eiao Island FP - DigitalGlobe Imagery - S to N

Focusing on Eiao Island first, one can see the eastern edge of the island made up of a severly slanting slope measuring 400-meters plus from top to bottom. This feature spans the entire western shore. The island is part of a submerged volcano. This eastern edge can be identified as the remaining above-water portion of a very large submerged caldera..

Eiao Island - DigitalGlobe Imagery Oblique View (W to E)

On the western side of the island one finds sheer cliffs of 300-meters plus. The bay shown in the above image is the traditional landing place for this island. The ascent to the plateau appears to be quite difficult from this location. The abundant vegetation above the landing place would support the reports that there is a spring located within the area. The island's plateau was once covered in a forest. It was rich in a diverse and unique flora and fauna. What little remains is in spite of the ravages of feral animals.

Eiao Island FP - DigitalGlobe Imagery - NE to SW

This is a seldom seen view of Eiao Island. The S to N view is a cartographic standard, however this NE to SW view shows the northern end of this island as having two potential landing places. They might be subject to heavy seas, but I would give the one on the left a try with a Zodiac. Also, access to the island's plateau seems more gradual from here as opposed to traditional landing places along the western shore that would involve strenuous treks.

Hatutu Island FP - DigitalGlobe Image Oblique View (S to N)

Finally, the oft cloud-shrouded Hatutu Island. My previous post describes my frustrations at obtaining clear images of this island. The one you see here is a composite. The southern portion is virtually cloud-free, whereas the northern portion is a thumbnail of imagery available from DigitalGlobe's extensive archive. So, I stitched the two images together, cut and pasted the ocean surrounding the island (for appearance sake) to create this Hatutu Island image. If you require imagery for serious work, call DigitalGlobe and they will fix you up. However, if you require a quick view that gives you an idea of the topography of this island, here it is.

Both islands, Hatutu and Eiao, are classified as Territorial Reserves. However, both islands still contend with feral animals (goats, swine, sheep, cattle, cats) that have devestated the flora and fauna of Eiao, and to a lesser extent, Hatutu. Now this is where a Hollywood star/activist could make a difference. They could, with the cooperation of local and national governments, fund a practiced group to remove these feral animals from both islands, thus allowing them to revert back to a pristine state. Any Hollywood takers? You could film a documentary about the adventure and make a few bucks, but the real payback is you get to reverse a man-made disaster and save an island. Now, that is worthwhile!

This post began as a "How To..." involving Google Earth's capabilities and DigitalGlobe's imagery, but has evolved into a celebration and a plea for help for two islands - Eiao and Hatutu Islands.

Enjoy and Help!

Labels: DigitalGlobe, feral animals, French Polynesia, Google Earth, Marquesas

Posted by Mr Minton at 5/28/2007 11:01:00 AM | Permalink | Comments | links to this post

Hatutu Island - Digital Globe Image (1:25,000)

Hatutu island - Marplot Map (1-25,000)

Let me begin by apologizing to the fine folks at DigitalGlobe. Their imagery for this island is actually depicted by the bottom half of the image composite. The upper, grainy image is a thumbnail of imagery they have in their archive for this island. So, if I would have had the northern imagery to combine with the southern portion of the island, you would be looking at a nearly cloud-free image of Hatutu Island, which isn't cloud-free very often.

However, the shoreline I was able to fashion from this composite is excellent, based on the available imagery. The shoreline would allow researchers the opportunity to plot information onto the island surface with reasonable accuracy. Let me modify that, with excellent accuracy based on currently available mapping.

Hatutu Island - West to East Profile Using SRTM Data

I'm still waiting for my funding source - merely a living wage, access to Digital Globe's extensive archive of Hi-Res imagery and then get out of my way and let me make maps to share with the rest of us FOR FREE. That's all I need. Any takers?

Enjoy!

Labels: DigitalGlobe, EVS, French Polynesia, Global Mapper, island, Marplot, Marquesas, SRTM

Posted by Mr Minton at 5/25/2007 06:54:00 AM | Permalink | Comments | links to this post

If you follow my posts, you will know that Eiao Island has been mapped a few times before. Once using a hybrid series of Landsat and WRS images and another time using SRTM data. It was a good effort, but there was a problem with clouds obscuring a portion of the shoreline.

Using Digital Globe HiRes imagery with 0% cloud cover, Eiao Island has been definitively mapped. Not only is the shoreline mapped with exquisite detail, as you can tell with the 1:8,750 scale map and image, but vegetation is accurately plotted.

Now to explain the title of this post, Don't Blow This Island Up!. Eiao Island was selected and explored by the French Nuclear Agency and French military as the next Pacific test site for nuclear devices. I believe the plan was to drill into the island and ignite nuclear weapons.

Hasn't this island had it's fair share of troubles. Well intended sailors and erstwhile settlers released pigs, goats, cattle and sheep. These critters have eaten much of the native vegetation. Way back when (not sure of the date) the French used Eiao Island as a prison. The prison was finally abandoned and the island reverted back to it's pigs, goats, cattle and sheep.

Now the French want to blow the island up. Eiao Island does not deserve this sort of mistreatment. Fortunately, the island was spared. The French government bowed to world pressure to halt their work to prep this island for nuclear destruction. Still, it is overrun by pigs, goats, cattle and sheep, but the nuclear devices are no longer a threat, for now. Let's hope forever.

view Eiao Island on Google Maps

Enjoy!

Labels: Digital Globe, EVS, feral animals, France, island, Marplot, Marquesas, nuclear weapons, Pacific

Posted by Mr Minton at 3/26/2007 11:19:00 PM | Permalink | Comments | links to this post

Motu One - Landsat Image N-07-05_2000

Motu One - Marplot Map

Motu One - ISS Image ISS009-E-5227

The mystery island of the Marquesas. Now you see it! Now you don't!

In the early days of sailing this reef, with it's small motu, was often misplotted, mischarted and mistaken. With the advent of Landsat images and Shuttle photography the mystery island is now precisely located northeast of Eiao (30-km) and Hatutu Islands (15-km). It's reef outline is based on shuttle imagery. I believe that a few hardy sailors have explored this reef both on land, scant tho' it be, and under the sea along it's extensive reefs.

Enjoy!

Labels: atoll, EVS, Global Mapper, island, Landsat, map, Marplot, Marquesas, Pacific, Polynesia, Tuamotus

Posted by Mr Minton at 12/21/2006 01:50:00 PM | Permalink | Comments | links to this post

Eiao Island - SRTM/DEM With Contours

Eiao Island - Contours 50-Meter Intervals

This was going to be a "How To" post, but I am not ready to tell you "How To" yet. I am still figuring all of the intricacies that apply to creating contours from Global Mapper. Needless to say, it is a fairly simple process. Load the SRTM DEM/HGT file, determine contour criteria, select "Create Contours" from the File Menu and you have created a series of contours.

Obviously, the contours are only as good as the underlying data (SRTM).  As I work more with the data and how it foots with Landsat and Google Earth 1-Meter Imagery, I will gain greater confidence in creating a new layer of information to be included with some of my high islands.

I think it could be a great addition to my EVS Islands. Just have to wait and see.

Enjoy!

Labels: atoll, EVS, Global Mapper, island, Landsat, map, Marplot, Marquesas, Pacific, Polynesia, SRTM

Posted by Mr Minton at 11/25/2006 12:32:00 PM | Permalink | Comments | links to this post

Eiao Island - Landsat Image S-07-05_2000

Eiao Island - Marplot Map

Eiao Island (8˚00'S., 140˚42'W.) lies SW of Hatutu; it rises to a height of 576m. The S coast of the island is formed by a perpendicular cliff, but the NW and W coasts are indented by several small bays. Its SE point displays a noticeable rock in the shape of an obelisk. The channel separating Eiao from Hatutu should be navigated with caution. A 6.4m shoal lies in the E entrance, while a reef, which has been reported to break, lies in the middle of the passage. The current generally sets NW through the channel with some strength.

The passage between Eiao and Motu Iti, further S, reportedly contains depths of 20 to 60m, and will be described with Nuku Hiva. Banc Hinakura, with a depth of 38m, lies 13 miles WNW of Eiao. A depth of 35m was reported 12 miles SW of the S extremity of Eiao, while a depth of 27m lies about 11 miles further SSW.

One can anchor at the opening of Vaituha Bay on the NW coast, in 27m of water, sand and mud, keeping the SW point of the bay bearing 247˚ at 0.2 mile.

In Charner Bay, also to the NW of the island, there is good anchorage, in 30m, sand and gravel, but it is not well sheltered from the swell which is felt strongly there. (SD PUB-126)

This is one of the first islands I became enamoured with. It is fairly large - 12kms by 4kms and 576m high. At one time, people lived on the island. Prior to European arrival, the island was vacated. It was visited by islanders to harvest stones to make adzes. The first Europeans to venture into the Marquesas were Spanish, then French and then American. The American, a Captain Porter, claimed to have discovered the northern islands (Nuku Hiva and north). He claimed these islands (including Eiao) as US possessions. Congress never acted upon his claim, so the islands remained French possessions.

At one time the island was used as a penal colony. Apparently, a few buildings/foundations still remain. In the 1970's/80's the French military suggested that the island be used to test nuclear weapons. They would drill into the island's core, drop bombs and explode them. The idea was rejected.

Today, the island is visited, on occassions, by divers. The island is infested with feral animals - goats, pigs, sheep, cattle and cats. No concerted effort to eradicate these island biota destroyers has yet been mounted. The feral animals are a continuing threat to the island's health. If you are a French authority reading this post, please sponser an effort to eradicate these feral animals from this small island.

Enjoy!

Labels: atoll, EVS, Global Mapper, island, Landsat, map, Marplot, Marquesas, Pacific, Polynesia

Posted by Mr Minton at 5/07/2006 04:44:00 AM | Permalink | Comments | links to this post