Thoughts - North Sentinel Island Five Years After the "Big" One

North Sentinel Island - Pre December 26, 2004

North Sentinel Island is home to a few hundred of the most isolated people on the earth. This group of people has chosen to remain separate from all other peoples. To the credit of India, they have been allowed to remain separate. Prior to December 26, 2004, the inhabitants were content to hunt and gather on their small forest covered island. Then came the dreadful 9.0 earthquake that caused death and destruction throughout this part of the world. North Sentinel Island was not spared. It is unclear if any of the inhabitants were killed as a result of the earthquake. What is clear is that the island underwent a dramatic transformation. This small island was thrust upward. The submerged reef was no longer submerged.

North Sentinel Island - February 2005

The February 2005 image shows the once submerged reef exposed above water. The forest is intact, but the island's fringing reef is now permanently above water. The stark white indicates that the reef is a new comer to the above-water environment.

North Sentinel Island - November 20, 2009

Fast forward to last month and one sees the reef still above water, but undergoing a gradual color change. As the once bone white reef remains in contact with the outside air, dust particles are blown onto the reef daily, algae colonies live and die and organic debris flows out from the island proper onto the reef, all of this contributing to the raised reef's gradual discoloration.

North Sentinel Island - EEVS Precision Map (1:62,500)

My post-earthquake map still gives a good picture of this small uplifted island. I'm glad it remains isolated and it's inhabitants have yet to encounter the world of modern man.

Enjoy!

Thoughts - They Aren't as Good as EVS Precision and That's the Fact , Jack!

Olimarao Atoll Locator Map

You all remember my last post, Olimarao Atoll? I spent a few days prior to posting it doing research into available online mapping. I checked out the standard mapping packages for Olimarao Atoll vicinity maps. Check out my results below...

Olimarao Atoll - Vicinity Map from Google Maps - Some land polygons, no labels.

Olimarao Atoll - Vicinity Map from Yahoo Local Maps - Nothing here.

Olimarao Atoll - Vicinity Map from Bing Maps - And nothing here.

Olimarao Atoll - Vicinity Map from OpenStreetMap - Land polygons and labels.

Google, Yahoo and Bing Maps rely on satellite imagery. The underlying maps of these oceanic island areas are largely neglected in map coverage. Google Maps provides land polygons from a mapping file similar to WVS 1:250,000. OpenStreetMap uses NGA PGS polygons along with NGA Country name files. Clearly the superior map product for oceanic islands is found on OpenStreetMap. But wait! What about a vicinity map using what I call EVS rough precision digitizing. Using Landsat ETM+ imagery, I could quickly digitize island polygons and reefs giving a much clearer map of the island.

Elato, Lomolior and Olimarao Atolls - Landsat N55-05_2000 Coverage

Landsat N55-05_2000 is the imagery I initially tried to work with. As you can see, The vicinity is not covered. It is a blank. So I did what any good mapper would do, improvised. Using Google Earth, I found the blank area and DigitalGlobe had hi-res imagery of the islands located within the blank area.

Elato and Lomolior Atolls - DG Preview Image from GE

Elato and Lomolior Atolls - DG Preview Image from GE Cropped

I decided to use the DG Image Preview from GE. I copied it, cropped it and georectified it. From there, I was able to complete the digitizing within a few minutes. I did this for all islands within the Landsat blank area. Atolls should have reefs digitized as they make up a critically important aspect of this feature. My finished map uses five layers - 1) land polygon 2) reef shallow 3) reef deep 4) ocean and 5) name labels. My island name layer is an extract from NGA's country files.

Olimarao Atoll - Vicinity Map from EVS Rough Precision (1-500,000)

This was all done using Global Mapper. The scale for the above map is 1:500,000. Now that is what I call a real oceanic island vicinity map.

Enjoy!

Olimarao Atoll FM - A Northern Pacific Island Jewel and Uninhabited Too

Olimarao Atoll - DG Island Image from GE (=~1:25,000)

Olimarao Atoll - EEVS Precision Map (1:25,000)

After almost five years of EVS precision island mapping projects, countless comments from the curious and, most often, complimentary guests and thousands of hours of work aimed at making this website better...

1) I have struck a deal with a corporate "sugar daddy" that will pay me to make EVS and EEVS precision island maps as I see fit.

or

2) My wife finally put her foot down and instructed me to "shut it down"! I told her to back off and she left me for a younger, computer illiterate man.

or

3) I'm still making island maps, with my wife's blessing, and am still without a corporate "sugar daddy".

Okay, I'm at Option 3) and enjoying it. However, sometimes our complicated lives cause us to wish for profound simplicity. A place where one can get away from the pressures of "big city" living and spend a day making a single decision, that being to make no decisions.

By far, my most popular posts over the past few months have been about the challenge of locating and living on uninhabited islands. It started with my post "Thoughts - An Uninhabited Island and What You'll Need to Inhabit it 'Robinson Crusoe' Style" and continued with my post "Thoughts - How Many Uninhabited Islands in the World?". These two posts alone have generated over 1,000 page views. As the world's economies continue to struggle and the economically downtrodden victims hunt for ways out, a Google search of "uninhabited islands" will lead the desperate to my aforementioned posts.

Olimarao Atoll could be their Eden. The atoll is small, but affords one fairly secure anchorage near the large motu. The large amount of vegetation suggests an adequate supply of water, most probably in the form of a fresh water lens. The small size of the island might lead one to "island claustrophobia", manifest by a longing for continental security. However, according to the occasional yachtsperson stopping for a short stay, the island is beautiful beyond imagination. Could Olimarao Atoll be your Eden? More to follow...

Enjoy!

Thoughts - Strange Maps: An Atlas of Cartographic Curiosities

Strange Maps: An Atlas of Cartographic Curiosities

When I first exchanged emails with Frank Jacobs, it was shortly after my "Titan's Unnamed Methane Sea" had hit the internet. The subject of the map hit a hot button that translated into 1,000s of visits to this web site. Frank introduced himself and asked if I had visited his blog, Strange Maps. I had and shared that I thought it was a "kick". He revealed that he, likewise, was a follower of my mapping efforts. He most especially liked my Titan map and wondered if he might use it in a book he was going to have published. He quickly added, that he had no money to pay for the use of the map, but would make sure I got a copy of his completed book. "Of course!" I said, "You are welcome to use my map. Just give me proper credit." Deal done!

Now let me tell you what I really thought. Oh, sure. This guy is going to publish a book about strange maps. I'll probably get a pdf copy or a link to his self-published effort. Unfortunately, I do have a healthy streak of skepticisim. After our exchanges I forgot about Frank and his book.

Silly me! I will never doubt Frank Jacobs again. True to his word, last week Fedex delivered a package from the UK. Inside was a slick copy of Strange Maps, Frank's book. I quickly leafed through it and there was my Titan map on pages 206-207. A nice writeup is included speculating on a name for this methane sea. And, sure enough, a paragraph about the author of the map, me.

Buy the book! Amazon.com lists it at $19.80. Support a fellow map lover!

Titan's Unnamed Methane Sea with Lat-Lon Grid (1-750,000)

And, once again, this is my map of Titan's Unnamed Methane Sea. It is still an interesting effort and now my first published map.

Enjoy!

Motu Iti FP - Smaller is Quicker

View Motu Iti FP in a larger map

Motu Iti FP - DigitalGlobe Image from Google Earth (1:10,000)

Motu Iti FP - EEVS Precision Map (1:10,000)

According to widely accepted geographical feature identification practices Motu Iti and the rocky islets to the east are classified as islets (> 1 sq km). They are still defined as islands for the purposes of claiming Exclusive Economic Zones (EEZs), sea level to seafloor ownership encompassing a radius of 200 nm or 370 km from this island's shoreline. Interesting as this might be, it is not the reason I mapped these islets. Yesterday, I needed a break from the Komodo Islands project and these islets looked like a good option. I like the Marquesas and these are a part of the Marquesas.

There was nothing especially challenging in the shoreline mapping of these islets. The DigitalGlobe imagery is exceptional. I did preliminary shoreline mapping in Google Earth and finished the project up using Global Mapper. I've spent about 4-hours from start to finish which is par for the course when mapping a simple island shoreline.

Now for my guess work. The main islet, Motu Iti, has scatter vegetation on it. My source, Vegetation of the Tropical Pacific Islands found in Google Books, states that three types of low lying vegetation are found on the islet (Perlman, unpublish notes, 1989). The main islet is said to be 220 meters high. Based on this unsubstantiated elevation, I guesstimated 25-meter contour intervals using visual interpretation of the base imagery. I was unable to use SRTM coverage for these islets as it is of very poor quality. It would be nice to have side views of these islets, but alas, no side views were turned up in my research. Consequently, the elevations are educated WAGs (Wild A...d Guesses).

I'll rest up today and spend time with my wife, doing long overdue honeydos. She will be happy and so will I.

Enjoy!

Thoughts - Working on the Komodo Islands EEVS Precision Island Mapping Project

Komodo Islands, Indonesia

Bima, Indonesia (txu-oclc-21752461-sc50-4) Perry-Castañeda Library
Map Collection

Why Make Another Map of a Previously Mapped Island?

The highly detailed mapping for this group of islands is paper. I create digital maps. The paper map lives in a library map drawer. My digital map will be available for any person wishing to use it. The raster imaged map above is a US 1:250,000 scale topo created from aerial surveys conducted in the 1940s and 50s. The scale my finished map will be useful is between 1:50,000 to 1:125,000. My map will contain additional layers of information detailing types of vegetation and reefs. Plus, I just like to make island maps.

Komodo Islands - EEVS Precision Digitizing using Landsat ETM+ Imagery (1:20,000)

Komodo Islands - EEVS Precision Digitizing using ASTER Imagery (1:20,000) Credit: NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team

Komodo Islands - EEVS Precision Digitizing, Size Modified (1:20,000)

Better is Better and More Accurate is More Accurate

I love the ASTER imagery for this island group. It is extremely detailed and provides a cloud-free look at almost all of the islands within this group. One is able to get an excellent view of different types of vegetation - mangroves, dense forests and scattered brush. Comparing it to the Landsat ETM+ image, the ASTER image provides a greater amount of cloud-free coverage. Combining the two images, ASTER and Landsat, one is able to create a virtually cloud-free image of the Komodo Island group. In the tropics, cloud-free is unique. One challenge was the georectifying of the ASTER image to the Landsat ETM+ image. It took 27 unique ground control points to twist, stretch and tug the ASTER image so that it precisely overlay the base Landsat image. Once that task was accomplished, I got around to digitizing layers of information. My first layer is always the island shoreline. Then comes all of the additional layers. I have completed the beaches and an inland vegetation layer at the northern end of Pulau Komodo and am currently working on the mangrove forest layer.

Pulau Siaba Besar and Kecil Islands - Landsat ETM+ Image (1:20,000)

Pulau Siaba Besar and Kecil Islands - ASTER Image (1:20,000

Pulau Siaba Besar and Kecil Islands - EEVS Precision Map, Preliminary (1:20,000)

Mapping at EEVS using ASTER Imagery

The above map is an example of the level of detail one can extract from the ASTER image. Those dark green areas along the island's shore are mangrove forests. Interestingly, these mangrove forests seem to primarily form along the eastern shores of the islands. This would be where the water is less turbulent.

Komodo Islands - Mangroves

The vegetation layer identified as EVS Vegetation Wetland, mangrove forest, detailed on the Pulau Siaba Besar map above, would look like the above image, dense dark green foliage along the shore. The dense dark green foliage that one sees inland will be classified as EVS Vegetation Forest (Hi). As you can see from the above image, much of the land is sparsely covered with vegetation. I have identified that layer as EVS Vegetation Scattered, which will include low lying grasses and small bushes.

Comparison - Landsat ETM+ to ASTER Images (1:5,000)

Pulau Siaba Kecil Island - DigitalGlobe Image from Google Earth, Size Modified (1:5,000)

Pulau Siaba Kecil Island - EEVS Precision Map, Preliminary, Size Modified (1-5,000)

Mapping at Scales Between 1:1,000 to 1:2,500 Using DigitalGlobe Imagery

In a perfect world, maps created from DigitalGlobe imagery found in Google Earth would be owned by their map maker and that map maker would be free to use that map anywhere and anytime they wished. No restrictions. No ownership delimmas. Just a map one would be free to use as one sees fit. But this world isn't perfect and DigitalGlobe and Google Earth have stern restrictions on how one is allowed to use their imagery. Pulau Siaba Kecil EEVS precision map was constructed off of DigitalGlobe imagery found in Google Earth. I am able to post my map, but there are restrictions on how I might use this map further. With that said, let's move on.

I decided to experiement using DGs hi-res imagery found in GE. I have used their mapping tools before and found them easy to use, intuitive and flexible. There are drawbacks, but one can work around them easily. The DG imagery allowed me to digitize the dense vegetation along the island's western shore. I have mixed feelings working with hi-res imagery. It is the best for extremely accurate work, but sometimes it is too much. If you aren't careful, you can find yourself digitizing the location of individual trees or offshore rocks. That is overkill for my maps.

All other mapping within the Komodo Island group will be taken from ASTER or Landsat ETM+ imagery. A variety of vegetation layers will be used, along with at least two reef layers. All of the islands are outlined and I am currently working on vegetation layers for Pulau Komodo. Wish me luck and...

Enjoy!

Robinson Crusoe Island CL - When This Old World is Getting You Down or Two Other Maps

Robinson Crusoe Island CL

Robinson Crusoe Island - Landsat ETM+ S-17-30_2000 (1:85,000)

Robinson Crusoe Island - DigitalGlobe Image from Google Earth (1:85,000)

Robinson Crusoe Island - EVS Precision Map (1:85,000)

When This Old World is Getting You Down

At times we all wish we could pull a "Robinson Crusoe", find some forgotten spot, seldom visited, yet replete with all the necessities of life - food, water, clothing and shelter. A place without financial pressures, martial woes, busy urban scene and no threat of crime spilling into our fragile lives. I'm not sure that place exists. Alexander Selkirk, the individual Daniel Defoe based his Robinson Crusoe character on, was so lonely by the end of his four year exile, he gladly rejoined the crew of the individuals who had originally abandoned him. His life on previously uninhabited Isla Mas a Tierra was often wretched. His diet was life sustaining, but challenging to gather. His clothing was handmade and unkept. His shelter is reputed to be a cave. He spent many lonely hours at his lookout scanning the horizon for a ship that might rescue him.

With that said, we still wish we could escape to his place. We all know in our heart of hearts we would do better. We would not grow lonely, but using our 21st century knowledge and preplanning, our island life would be a special time to reflect on the world and all of its mysteries and how we fit into them. When we grow tired of our adventure, we would merely dial our satellite phone and be whisked away, back to our previous lives.

Robinson Crusoe Island - Wikimedia Commons

Robinson Crusoe Island - Source Unknown (1:120,000)

Two Other Maps

A map is seldom an entirely unique creation. Robinson Crusoe Island has been mapped many times. Some of these are excellent compositions. I used two other maps to aid in the construction of my map. The first one, found in the Wikipedia article on Robinson Crusoe Island was used to gather feature names. The second map, source unknown, was used to confirm certain feature names and supply any new ones not found on the first "helper" map.

The vector files making up my EVS precision map were created using Landsat ETM+ and DigitalGlobe from Google Earth. The majority of the shoreline was extracted from DigitalGlobe imagery. Where clouds obscured the land, I used Landsat to map the underlying area. The 50-meter contours were derived from SRTM data. There is a problem with the elevations, some of the higher elevations are dramatically different than what they should be. El Yunque Peak is supposed to be 913-meters, but is shown to be approximately 650-meters using SRTM data. I did not correct the erroneous elevations in this version of my map. Perhaps, I'll correct them later.

Robinson Crusoe Island - Chilean Nautical Chart 5410 (1:50,000)

Finally, for all of you sailors that wish to explore Robinson Crusoe Island, the Chilean Hydrographic Office (SHOA) has a nautical chart you might wish to purchase. The above image is a copy of it.

Enjoy!