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

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

I have wanted to map this island for quite some time. Landsat imagery was full of clouds, not good to map details of both shoreline and the island proper. I located some ISS imagery that was relatively clear. The resolution was crude compared to Landsat. Finally Google Earth managed to snag some 1-meter resolution Digital Globe imagery. I had the perfect image, now I just needed time, like Christmas vacation. I have worked on this map and the various layers for about 10-hours. The shoreline is as good as it gets. The northern end of the island is cloud obscured and I had to use ISS imagery to approximate the shoreline. However, the bulk of the shoreline is crystal clear.

Mapping in Google Earth is a challenge. In Marplot it is easy to create multiple features within the same layer (i.e., five Cypress Tree Groves). In GE, each feature stands by itself. I had to create five separate files for each grove of trees. The problem comes when you have many features (i.e., small islets ringing this island). I had to create 13 separate KML packets. Each had to be handled separately to reformat so that they could drop into Marplot.

This island was ravaged by a variety of feral animals, goats and rabbits primarily. The goats eat anything and everything. They were eating the Cypress tree seedlings. They were destroying this unique ecosystem. The Mexican government and US agencies have worked cooperatively to eradicate these feral pests. I noticed that the large stands of Cypress trees are ringed by fences. Reportedly, the goats are almost completely gone. The fragile ecosystem is recovering.

Not in our lifetime, but in our children's children, they will be able to visit a verdant forest that will cover the entire higher elevation of this island. They will stay in a swank lodge and for fun take long hikes. No, not in our lifetime, but perhaps our children's children will experience it.

Enjoy!

PS - The SRTM data was great, so I created 100-m interval contours. Now the map image contains the EVS Contours layer. And now I am finished with Guadalupe Island.

Labels: Digital Globe, EVS, feral animals, GEVS, Google Earth, Guadalupe Island, island, map, Marplot, Mexico, Pacific

Posted by Mr Minton at 12/28/2006 01:07:00 PM | Permalink | Comments | links to this post