The above map shows some of my completed island mapping projects. Each icon contains the name of the primary island associated with the project and a link to the post. Once all of my projects are posted, the map will be covered with icons. To productively use the map, zoom into a region of interest. Then select an icon.

Each of my maps is constructed of numerous layers of information. All of the layers are vector files. I will make these files available upon request. You are free to use them with certain restrictions - 1) Don't sell them. You can use them on research projects, post them to your website or things of that nature. If you aren't sure about the use of my maps, drop me a line and we can discuss your idea. 2) Give me credit when you use my vectors or images of my maps. Credit them to Peter Minton @ EVS-Islands

If I have the island vector file(s) and based upon your need, I will make them available. Images of my maps are yours to download and use, with the above restrictions applicable. Enjoy!

Friday, July 07, 2006

Rapa Island FP

Rapa Island - Image

Rapa Island - Landsat Image S-07-25_2000)

Rapa Island - Map

Rapa Island - Marplot Map

POL - Rapa Island

Rapa (27˚36'S., 144˚20'W.) is an irregular, circular form about 4.5 miles in diameter. There are several deep indentations in the shore; the largest is Baie de Haurei on the E coast.

Winds—Weather.—The prevailing winds from October to April are from the E, but about once in three weeks, during December, January, and February, W winds occur for a short period. From May to the middle of September, W winds with heavy showers prevail, blowing down the valleys into Baie de Haurei; the strongest W winds are felt in July and August. From native reports, typhoons are sometimes experienced. Gales of cyclonic character, though not common, occur at all times of the year. The climate is generally temperate but moist; rains are frequent. The island is often covered with clouds and fog when the weather is clear a few miles out to sea.

Aspect.—Ahurei (Haurei), a village, is situated on the S shore of the bay, 1 mile WSW of Pointe Maomao. The aspect of the island is remarkable; where the steep sides of its high, jagged peaks reach the coast, they become great cliffs falling almost vertically to the sea. The island rises to a height of 650m in its W part. The mountains on the E side of the island are generally either bare or with a growth of stunted trees. On the W side, they are covered with a rich vegetation, and most noticeably with forests of large tree ferns.

The shore is bold and has no off-lying dangers beyond 0.5 mile, except in the approaches to Baie de Haurei, where spits and shoals extend nearly 1 mile seaward. A shoal covered by 30m of water (locally called Maaki Shoal) is located 20 miles ENE of Rapa Island.

Baie de Haurei (27˚37'S., 144˚20'W.) (World Port Index No. 55857), open to the E, is entered between Pointe Tekogoteemu and Pointe Maomao, 0.6 mile SSW. It is protected from the prevailing E winds, and from the heavy sea, by the shoals in the approach. The land surrounding the bay rises rapidly from the shore. The white dome of a weather station is visible on the S side of the bay.

Depths—Limitations.—The entrance is narrow and tortuous, and has a least depth of 5.8m. Three sets of range beacons mark the channel, which is only 90m wide and should not be attempted with any type of cross wind. Shoals, with a least depth of 1.2m, are prevalent along the edge of the channel. Shoal water extends 0.4 mile S of Pointe Tekogoteemu, and 0.5 mile E of Pointe Maomao.

Pilotage.—A pilot is recommended for vessels without local knowledge. The pilot may be requested in advance by radio through Tahiti. Local pilots may be available, but it should be kept in mind that he will have little experience in handling vessels other than local craft. It is strongly recommended that before the channel is attempted, a preliminary reconnaissance be carried out to verify the beacons, and mark the edges of the shoals to be avoided, when altering course from one alignment to the next.

Anchorage.—Anchorage outside the shoals is available, in depths of 11m, with Pointe Maomao bearing 279˚, 1 mile distant.

Within the bay, large vessels anchor when a stone temple with a gray roof situated on the S side of the bay bears 213˚, in depths of 10 to 15m, indifferent holding ground. With E winds, the anchorage inside the bay is protected, but with W winds, violent squalls may blow down from the high land. Vessels over 100m in length should not remain anchored overnight. (SD Pub-126)

Additional information about Rapa from the Aranui website.

The only island in French Polynesia that is below the tropical zone, remote Rapa stands proudly alone at 1,074 km. (666 miles) southeast of Tahiti, 600 km. (373 miles) distant from Raivavae, its closest neighbor. The crescent shaped island has a circumference of 18 miles (30 km.), and there are 12 deeply indented bays along its fjord-like coastline. There is no fringing reef in these cold waters and several sugar-loaf shaped islets lie just offshore. Rapa was first sighted by English Captain George Vancouver in 1791.

Rapa-Iti, as the island is also called, has a strong cultural connection to Rapa-Nui, the Polynesian name for Easter Island. Rapa’s 500 inhabitants are strong survivors, descendants of fierce Polynesian warriors and kings, hardy sailors and pearlshell divers. The entire community owns the land and the simple houses are grouped together in Haurei Village and in the smaller village of Area, which is reached by boat across Haurei Bay. There is a town hall, post office, infirmary, weather station and school. A cooperative store provides the villagers with basic supplies and many of the homes have television and telephone service. Archaeological ruins include the remains of seven famous pa fortresses built on superimposed terraces among volcanic pinnacles. These structures were found nowhere else in Polynesia except New Zealand where the Maori people settled. Mt. Perahau, the highest of six peaks, hides among the scudding clouds at 650 meters (2,145 feet) above the island. Herds of cattle, sheep and wild goats roam the velvety green mountain ridges, and farms of coffee, taro, cabbage, apples, oranges, and peaches supplement a diet of fresh salmon, cold water lobster, mussels, oysters, crabs, bêche de mer, shrimp and sea urchin, with occasional portions of beef and tender goat meat from the cooperative store. The South Seas staple of canned corned beef is scorned in favor of fresh food. Because it is below the tropical zone, the coconut trees on Rapa do not produce many nuts.

The temperature in this southerly clime can drop to 5 degrees Celsius (41 degrees Fahrenheit) during the Austral winter of July and August, when violent winds blow across the turbulent open seas, bringing cold temperatures up from the South Pole.

There is no airport on Rapa and supplies are brought in by cargo ship from Tahiti. There are no tourist facilities other than a bed or room in a private home. Even though this lonely island almost at the bottom of the world is difficult to reach, there are still venturesome souls who heed the call to those far away places.

Written by Jan Prince; Photos by Tahiti Tourism Board, Danee Hazama, J. Sekkaki, D. Travers, J. Bourke, L.Pozzoli


Rapa Island - Shuttle Image

Rapa Island - ISS Image ISS004-E-12979

The "ace-in-the-hole" image. This project took about 6-hours to complete, but it was one interesting journey. The cloud covered base image left too many serious gaps in the shoreline of Rapa. I got a cloud free WVS-2 image that showed the eastern half of the island and I was able to digitize a portion of the shoreline. In addition, I located an nautical chart reproduction

Rapa Island - Charts

Rapa Island - Copy of Nautical Chart

(Quarterly Journal of Geologic Society, 1933)

I remembered space shuttle imagery, so I checked it out. There was an image that was virtually cloud-free. A few problems. The image was turned the wrong way. And it need to be skewed and stretched. After lots of work in MS Paint, I got the image squared away. I imported the image into Marplot, georegistered it and digitized the shoreline. I then imported both my new shoreline and the PGS shoreline into Global Mapper where, using the PGS map file along with my new shoreline, I was able to fill in the cloud gaps with accurate shorelines. It is truely a slick effort. Rapa Island hasn't had it's shoreline digitized and mapped like mine effort ever.

PS - Why Rapa Island - Back when I was a young man feeling my "oats", I read about Rapa. The article stated that because of the lack of work on the island, the young men were leaving to get employment. Once they had been away for a few years, they didn't return. The article went on to state that there was a serious problem within the existing population - there were 7-women to every man on this island. Furthermore, the majority of these men were old. I knew that I had found paradise. I do not have more current information

Enjoy!

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Thursday, July 06, 2006

Thoughts - Why Everyone Should Construct Their Own World Shoreline Vector Map - The Reasons

I was so excited about posting the previous post that I forgot to tell you "why" you should make your own WSVM.

First - Just for the thrill of doing it. Taking software and vector files, smashing them together and getting what you set out to obtain is real cool! It is a challenge that can be met. Do I expect any of you to make the WSVM just because it is cool? Maybe. But, I do know that some of my vistors are folks like me, with a passion for maps and the craft of map making. And some of those visitors love a bargin, like free stuff. If you follow the steps, you can make your very own WSVM.

Second - All of us need to keep our creative juices flowing. Sure, you can purchase an atlas for a few bucks. It will show you the world according to the atlas maker's vision. But, how much more satisfying is it when you construct the world according to your vision. It is much more difficult, time consuming and challenging smashing all of that data together and eventually getting your very own WSVM creation. It is deeply satisfying.

Third - It is so good to be a life-long learner. We all need to learn. Learn about new software. Learn about shorelines and what they define. Learn about islands scattered about our seas, oceans, lakes and rivers. Learn about magnificent river deltas that splash out into oceans. Learn about the Caspian Sea shorelines. Learn, learn learn!

Those are three very good reasons why one should make their very own WSVM. Take it from me, I have made probably 10 to 15 WSVMs. They all come out differently. Yes, they show world shorelines, but how they show them is my choice. And I love making that choice!

Thoughts - Why Everyone Should Construct Their Own World Shoreline Vector Map

I am relaxing, listening to Boz Scaggs singing "Harbor Lights" and I am thinking about why it is so important that everybody should learn to construct their very own World Shoreline Vector Map (WSVM).

First, my regular visitors know that I use a "poor man's" mapping program called Marplot. It is free and it works for my purposes. If you follow the above link, you will wonder why someone would bother to put a world shoreline vector map into software that was designed for EPA useage. Again, it is free and it works. When you install the program you will find a Maryland county pre-loaded. I believe it is Prince William County. You will see a very busy image. As you zoom in you will begin to distinguish roads, building locations, and various other Tiger info. To build your WSVM, you must delete these layers of information. Once these layers are deleted you can begin to prep Marplot for importing of vectors to create your WSVM. I name my layers for the data I am importing into them. For example, when I created the NGA Prototype Global Shoreline (NGA PGS) layers, I named them NGA PGS ## (appropriate number associated with the file). I also create a layer group (NGA PGS Shorelines) that holds all of the associated layers.

So, lets create a NGA PGS World Shoreline. Go to NGA PGS site and download each of the 32 files onto your desktop, or other storage device. They will arrive as zipped shp files. Now for the "poor man's" data conversion secret - shptomie.exe. It is a small, efficient program that does one thing well - convert shp files into mie formats. The program downloads ready to go. You will be asked to identify, from a list of choices the name for each object. Pick one. You won't use it, but it is fun to do. Next, you select the Marplot layer. I would name them for each file. For example, file #1 would be layer NGA PGS 1 and so on. Next, and very important, name the map you will import into. My map is called World Shoreline. Each file fill be imported into this map - World Shoreline. Each file, all 32 of them, will occupy their own unique layer. Trust me, it makes for fast importing and flexibility when working with your map. Once all of the files have been converted and placed into your NGA PGS folder, located on your desktop, you can begin importing them into Marplot.

The importing process is simple and typically fast, depending on your computer. From within Marplot select from the menu - File, Import and then go into your folder and select the first mie file to import. Import it - it is a Marplot formated file! When it is completed, import the next file. Bring in all of the 32-files, one at a time, each into it's own unique layer. When they are all into Marplot , you get to define the layer.

Construct a group layer to place all of the NGA PGS layers into. Select the layer, ctl-i, select the group and enter. Do that with each layer until you have each of the layers into that group layer. Then select the group and determine an appropriate color for the lines, thickness, fill or no fill, and symbol. Then select Range and determine when to show the layer and when to hide it. Don't show names or icons. A practical range for the NGA PGS is 1-cm = 120-km. When you go out farther than that the load time is very slow.

My WSVM contains shorelines for 1:2000000 scale available from NOAA Coastlines. I downloaded by WSVM @ 1:2000000 in sections and in ARC/Info Ungenerate format, which drops straight into Marplot. But, this is another story.

PS - I realize pictures would have made this post much more practical, but - so it goes. If this post tickles your fancy and you would like to give this exercise a try and you require more info, drop me a line and I will talk you through it.

PPSS - And yes, I know that there are powerful mapping packages, some of them at little cost others quite costly, that will map rings around Marplot. Marplot works for me and I am sure it can work for others.

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Wednesday, July 05, 2006

Comparison - EVS, PGS, WVS and SRTM (1) Shorelines

Comparison 4-Vector Shorelines (1)

Comparison of EVS, PGS, WVS and SRTM (1)Shorelines

A picture is worth a thousand words. The above image contains a small segment of Eiao Island FP. The scale is 1:12,000. What are visually displayed are the shorelines of various global shorelines (PGS, WVS and SRTM (1)) as they compare to my own EVS shoreline. They all fall short of depicting the actual shoreline and that is to be expected. A shoreline is a dynamic geologic entity. It is constantly in motion. There will never be a penultimate map (a static entity) that depicts a global (dynamic) shoreline. With that said, which of the four shorelines works best for your needs. All four shorelines have their uses.

The World Vector Shoreline, "old reliable", works for most mapping needs at a scale of 1:250000 or above. When you work above 1:2000000, the map becomes too busy. But between those two scales, WVS works fine.

Prototype Global Shoreline, when completed, will be "THE" map file for work from 1:62,500 up to 1:1,000,000 scale. It will provide details that will make WVS look like a clunky jalopy compared to a sleek race car. PGS will impact every country in the world. It will require a country-by-country acceptance. It will cause nations to redefine maritime limits and that is not an easy notion for nations to agree upon. Nations will gain or lose valuable real estate because maritime base lines and economic zones will be shifted because PGS shorelines will shift. If the shift results in a lose of real estate, my suspicion is the losing nation will not buy the new boundary. What an exciting proposition for the global community. Much of the above comes from a source within NGA that has the enviable task of completing this monumental map file.

SRTM (1)(SWBD) shoreline was added to show how far this vector mapping program has advanced. It is a solid vector map file that improves mightily upon WVS, but it does not accomplish the precision that is found in PGS. However, again from my source in NGA, there is a more precise global data source within SRTM. It is SRTM Level-2. It is available for the US today, but NGA has access to global coverage at the level-2 precision. I am purposely vague on SRTM Level-2 as I have not done much work with it, but I am certain it will perhaps rival PGS when released to the eager public.

Finally, my own Enhanced Vector Shorelines effort and how it compares with the other three shorelines. I like to think that EVS is the most accurate of the four, but that isn't quite so. The three are global in scope and mine covers islands and some shorelines. The places I have mapped at EVS resolution are more exact in depicting the actual shoreline than any of the other three shoreline sources. My ultimate goals with EVS is to see all shorelines mapped at that level of precision, to develop a consistent decision-making process as to map or not to map certain features and to bump this effort up into a legitimate concerted, well-funded effort that will result in a timely completion of the project within 2 to 3 years.

EVS, in my opinion, is the ultimate map file that can be extracted from Landsat-7 ETM+ 2000 imagery. When 1-meter resolution imagery is released and the coverage is global, the new and improved ultimate map could be created, EEVS (Extremely Enhanced Vector Shorelines). Until then, I will keep myself busy working on my labors of love – creating shoreline maps of islands.

Enjoy!

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Tuesday, July 04, 2006

Comparison: Admiralty - French Admiralty and EVS

Comparison Nautical Charts

Comparison of Admiralty Chart, French Admiralty Chart and EVS Shorelines

The above map is taken from Bulletin 70, Bernice P Bishop Museum (1930). It is a copy of an Admiralty Nautical Chart No. 2868 and French Admiralty Chart No. 4962. The red "fat" shoreline is my digitized EVS shoreline. It was taken from Landsat S-06-20_2000.

I will acknowledge that the nautical charts were based on pre-satellite cartographic skills. These charts are off. They are 1-minute by 1-minute off from the true position of Tubuai Island. The brown lines are the charts lat / lon (23 23S 149 27W) whereas the red line shows the map's lat / lon (23 23S 149 27W). The chart is off by 1.7-kilometers.

The misplot is either due to a datum difference (Unknown datum compared to WGS-84) or an error. I would tend to favor the error problem, but it could be a datum problem.

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