Tuesday, January 15, 2013

Navigational backup to aid ships in Dover straits

Loran coast stations
Loran-C systems are in place in some 16 countries worldwide, including Europe, Russia, the Far East and North America, although the transmitters in the US have been switched off, pending a decision on upgrading to eLoran.
At the instigation of the UK and other member administrations, the International Maritime Organisation is developing e-Navigation as the future approach to marine navigation.
There is a strong opinion that this development cannot be realised without a resilient positioning system in place and that this means a terrestrial backup to GNSS – eLoran is the only possible candidate within the timescales envisaged for the project.

From BBC

Ships traversing the busy Dover Strait now have more help to work out where they are and avoid other vessels.


UK switches on GPS backup in the English Channel
The Channel is used by between 400 and 500 vessels a day,
including ferries, oil tankers and cargo ships

A technology called eLoran has been turned on to help navigation if Sat-nav based systems (aka GPS) fail or are jammed.

The General Lighthouse Authority (GLA) has turned on a radio station which broadcasts fine-tuned eLoran signals.

Ships fitted with eLoran receivers will now be able to use the backup radio signal to reach port.
Atlantic Loran coverage

Station location and coverage areas of the LORAN radio navigation system

Longwave alternative

The eLoran technology is based around longwave radio signals that are broadcast from nine separate stations in Northwest England, France, Germany, and the Faroe Islands.

Now added to this is a GLA station in Dover that broadcasts corrections to eLoran that makes signals so precise ships can enter harbours using them in the event of GPS failure.


Example of an eLoran service provision for maritime users

In a statement shipping minister Stephen Hammond said the technology should improve navigational safety in "the busiest shipping channel in the world".

Maritime navigational instruments tend to rely on GPS positioning which employs timing signals broadcast by a constellation of satellites. However, GPS signals can fail or be fooled by a conflicting radio signal, said Professor David Last, an advisor to the to General Lighthouse Authority.
"The problem is, many vessels are wholly dependent on GPS, " Prof Last told the BBC.
"GPS can and does go wrong."

 Example of map including Loran-C hyperboles grid lines (NOAA US)
 >>> geolocalization with the Marine GeoGarage <<<

GPS signals are weak, and so can be disrupted by solar storms, or by a stronger signal broadcast in the vicinity by a GPS jammer.
Compact GPS jammers that run from a car are available to buy, although use is prohibited.

GPS is used to determine a ship's position and direction, and for communications.
All ship's instrumentation is integrated, so if anything goes wrong, the systems can completely fail.

GPS can be disrupted by a weak signal broadcast on the same frequency, said Prof Last.
The weak signal can cause a ship's instruments to gradually drift out of true, without setting off any alarms, leaving the ship in a different position to where it "thinks" it is.
"The ship will drift away from its true position, and slowly start to turn," said Prof Last. "It's insidious."


An eLoran receiver has been installed on a P&O Ferries ship,
but the GPS alternative is not widely use
“Accurate real-time positional information is essential for the safe navigation of ships with modern electronic charts,” said Captain Simon Richardson, Head of Safety Management at P&O Ferries says


eLoran is not widely used on commercial shipping, although an eLoran receiver has been installed on a new P&O Ferries ship, called the "Spirit of Britain".

Links :

Monday, January 14, 2013

Vendee Globe : Fernando de Noronha

14/01/2013 10:00 UTC situation

 >>> geolocalization with the Marine GeoGarage <<<

From EyesofBrazil

Fernando de Noronha is an archipelago in the Atlantic Ocean, part of the State of Pernambuco, around 354 km offshore from the Brazilian coast. Its area is 18.4 km2, its population 2,051 (as of the year 2000).
The area is a special municipality (distrito estatal) of the Brazilian state of Pernambuco.

 >>> geolocalization with the Marine GeoGarage <<<

The archipelago is named after the rich Portuguese merchant of the same name (although he was born Fernão de Noronha and has also been known as Fernão de Loronha).
Under contract by the Portuguese Crown, Noronha sailed westward in search of pau-brasil (an in-demand wood with a distinctive red dye, from which Brazil gets it’s name).
He and his crew of explorers ended up “extracting” aprox. 1,300 tons of this special wood and selling it in Lisbon at a mark-up of 400% to 500%.
As a result of his successfully completed contract, King Manuel I handed the first captaincy of the sea to Noronha, which encompassed of the archipelago.
Also of interest, is the fact that Noronha married off his daughter, Isabel de Castro, to the explorer Pedro Cabral, who “discovered” Brazil.

Beach on Fernando de Noronha island :
 "The moment one says it is a moment of perfection, it is something less than perfection.
So on the island of Fernando de Noronha, I will be quiet now.
I will let the birds speak Portuguese.
I will let the waters speak dialects of green.
I will let the rocks tell me I was never really born; and the vistas carry my insights to an early death.
I will let the breeze nudge my years off one cliff here and one cliff there.
I will let the air confiscate my passport.
And I will let the sand send my battles to the sea.
Let them all simply make an island out of me.
The moment I say I am lost without love, I will be something less than lost."
Howard Altman poem ('In this House')

Geology

The islands of this archipelago are the visible parts of a range of submerged mountains.
Consisting of 21 islands, islets and rocks of volcanic origin, the main island has an area of 18 km2, being 10 km long and 3.5 km at its maximum width.
The base of this enormous volcanic formation is 756 m below the surface.

The main island, from which the group gets its name, makes up 91% of the total area;
the islands of Rata, Sela Gineta, Cabeluda and São Jose, together with the islets of Leão and Viúva make up the rest.

Ecosystem

The main attraction is the maritime flora and fauna; one can spot sea tortoises, dolphins, albatrosses, among many others.
Fernando de Noronha is considered the best scuba diving place in Brazil.
Warm water and exuberant sub aquatic fauna and flora can be found in dives from 25 to 40 m deep.
A Brazilian warship, the corvette NaeL Ipiranga, sank in 1987 and is lying in pristine condition at around 190 feet.

In and around Praia Sancho, is a reserve for some 600 spinner dolphins (photo)

Nowadays, Fernando de Noronha’s economy depends on tourism, restricted by the limitations of its delicate ecosystem.
In fact, there is an Environmental Protection Tax of roughly US$10/day just to visit the island which if I’m not mistaken must terminate (along with your stay) after a period of 30 days.
In addition to the historical interest noted above, the archipelago has been the subject of the attention of various scientists dedicated to the study of its flora, fauna, geology, etc.

 >>> geolocalization with the Marine GeoGarage <<<
In 2001, UNESCO declared Rocas Atoll with Fernando de Noronha, a World Heritage Site.

Colonial Prison

Long before becoming the touristic and ecological paradise that it is today, the archipelago housed a prison which stood from 1737 until 1942.
In the remaining years, starting from 1938, only political prisoners of the Estado Novo regime were sent there.
A report from the magazine O Cruzeiro, from August 2nd, 1930, describes the prison as an infernal ghost for these people banished from society, that live completely distanced from what is happening in the rest of the world, in spite of the Government giving the prisoners a healthy life of work and comfort.

Ecological Problems

Although protected by the National Park designation, much of the land-based ecosystem is destroyed. The largest part of the original vegetation was cut down in an effort to stop prisoners from making rafts and escaping.
There is also the problem of invasive species, especially the flax seeds, originally introduced to feed the roosters.
It now is out of control and threatens the existing vegetation.
Without the plants for cover, the islands can’t retain water during the dry season, so the vegetation turns brown as a consequence of drying out.
Another invasive species is the lizard, locally known as teju, which was introduced to control the rat population.
The idea, however didn’t work as the rats are nocturnal and the lizards aren’t, which has made the growing lizard population the more pressing problem.

Detail from the 1502 Cantino planisphere, showing the island of "Quaresma"
(Fernando de Noronha?) off the Brazilian coast

History of Occupation

Many controversies mark the archipelago’s discovery by Europeans.
From its original name, Ilha da Quaresma (Lent Island), it was sighted by expeditions in the years 1501, 1502 and 1503.
The Viscount of Santarém, however, attributed the discovery to Gaspar de Lemos, captain of the supply ship of Pedro Álvares Cabral’s fleet, sent back to Portugal with news of the discovery of Brazil.
Modern historians, however, credit the 1501-1502 expedition led by Fernão de Noronha with the discovery of the archipelago.

 Philippe Buache, Paris, 1737 (BNF)

The first to actually describe the island was Amerigo Vespucci, who travelled with a Portuguese expedition of Gonçalo Coelho to Brazil in the year 1503.
In 1534, the Fernando de Noronha Archipelago was invaded by the English, and from 1556 until 1612, it was held by the French.
In 1628, it was occupied by the Dutch, who were displaced two years later by a Spanish-Portuguese military expedition led by Rui Calaza Borges.

 English manuscript chart on paper of a bay on Fernando de Noronha.
Many names in English, to the lower left.
A rare example of a manuscript sea chart, probably from the Thames School, with intriguing early annotations, perhaps used in the offices of the British Navy. 
This draft is extremely Erroneous.

The Dutch occupied the island once again in 1635, making it a hospital for their troops who occupied Northeastern Brazil (the Brazilian coast between Rio São Francisco and Maranhão).
The island became known as Pavonia, in honour of Michiel de Pauw, one of the directors of the Dutch West Indies Company.
It would remain under Dutch control for nearly twenty years, when it was reconquered by Portugal.

Finding it uninhabited and completely abandoned in 1736, the French East Indies Company took the island and renamed it Isle Dauphine.
Only from 1737 on, after the expulsion of the French, Fernando de Noronha was definitively occupied by Portugal.
This time it was decided to fortify the island.
For this purpose, ten forts were built in all strategic points where a possibility of disembarkation existed; nine in the main island and one in the Ilha de São José situated in front of the Saint Anthony harbour.
The forts were connected by a network of stone roads.
This defense system was planned by the Portuguese military engineer Diogo da Silveira Veloso. Around 1770, the first permanent settlement, Vila dos Remédios, was founded.
The village was divided in two units (pátios); in the superior one were the administrative buildings, in the lower one the church and the associated religious buildings.

As Brazil became independent, very little changed for Fernando de Noronha.
At the beginning of the 20th century, the British arrived to provide technical co-operation in telegraphy (The South American Company).
Later the French came with the French Cable and the Italians with Intalcable.

 >>> geolocalization with the Marine GeoGarage <<<

In 1942, during World War II, the archipelago was made a Federal Territory that also included Rocas Atoll and Saint Peter and Paul Rocks, and political and ordinary prisoners were sent to the local prison. In 1988 approximately 70% of the archipelago was declared a maritime national park, with the goal of preserving the land and sea environment.
On October 5, 1988, the Federal Territory was dissolved and added to the state of Pernambuco (except Rocas Atoll, which was added to the state of Rio Grande do Norte).

Ernest Shackleton voyage to be retraced by modern-day Antarctic explorers


Sir Ernest Shackleton's Trans-Antarctic Expedition is one of the greatest survival stories in history and has inspired adventurers across every continent over three generations.
Now, in honour of Shackleton's legendary expedition, a crew of five British and Australian adventurers will join expedition leader Tim Jarvis, AM FRGS, in an attempt to become the first to authentically re-enact Shackleton's complete 'double' voyage from Elephant Island to South Georgia and dangerous crossing of its mountainous interior.

From HuffingtonPost

A group of intrepid explorers are readying themselves for the first-ever recreation of the epic voyage made by British explorer Ernest Shackleton on his ill-fated attempt to reach the South Pole in 1914, on an exact copy of Shackleton's lifeboat.


Shackleton's boat, the Endurance, became trapped in the Antarctic ice and was eventually crushed and sank.
His attempt to raise the alarm is considered by many to be one of the greatest journeys ever made.


Shackleton took a small party from his crew and rowed 1,287 km (800 miles) on the lifeboat James Caird from Elephant Island to South Georgia, where they knew they could get help from a whaling station.


Their journey took from 1914 to 1916.

The British and Australian team, led by Australian explorer and environmentalist Tim Jarvis, will row the same route and then cross the mountainous, glacial interior of South Georgia to reach the north coast.
They will use no equipment that was not available in Shackleton's time.


The Shackleton Epic team will depart from South America in early January, rowing an identical copy of Shackleton's 6.85 meter (22 feet 6 inches) lifeboat before climbing the mountains.
The journey will not be without danger.
The replica boat, named the Alexandra Shackleton after the British explorer's granddaughter, has no keel and capsizes very easily.
"You know, we ran the numbers and said what can we do with an exact replica of Shackleton's boat, without cheating, to try and make this ... less susceptible to capsize than what he had," Jarvis said.

 Elephant island
(photo  Ralf Müller)
>>> geolocalization with the Marine GeoGarage <<<

The team have practiced capsizing the vessel and trying to right it again, and have attempted to use their supplies, equipment and rocks as ballast instead of just rocks as Shackleton did.
"We ran all the numbers, we fiddled around with rocks and our camera batteries because we are filming this ... and you know what? We came up with exactly the same configuration of how the ballast was loaded as what Shackleton did with rule of thumb," Jarvis said.
"It's amazing to think that (after) a hundred years, with all of our modern thinking, we've ended up with exactly what Shackleton had. But yeah, it's still a very tippy, very unsafe boat," he said.

Jarvis was toasted at a presentation in Sydney at the weekend with an identical whisky to that carried on board the original Endurance, served in tin mugs for added authenticity.
Jarvis, an environmental scientist and an experienced explorer, said he was inspired by Shackleton's leadership style and his ability to turn disaster into success.
He also said Shackleton's story was an ideal platform to promote his environmental message.
"Well, Shackleton was trying to save his men from the Antarctic and we're now trying to save Antarctica from man," Jarvis said.

Links :
  • StuffNZ : Retracing Shackleton in Antarctica
  • TheGuardian : Shackleton's journey: what adventures are left to emulate?
  • DailyMail : The quest to find Ernest Shackleton's lost ship Endurance that disappeared beneath the ice of the Antarctic nearly a century ago
  • TheIndependent : Team sets out to replicate Shackleton's epic journey

Sunday, January 13, 2013

Image of the week : red dust storm goes over the ocean

A towering red dust storm goes over the ocean ahead of a cyclone
approaching Onslow on the West Australian coast, on Jan. 9.
>>> geolocalization with the Marine GeoGarage <<<

Tug boat worker Brett Martin, who captured the fearsome pictures 25 nautical miles from the town of Onslow, reported conditions were glassy and flat before the storm hit late on January 9.

But when the wild weather arrived, the swell lifted to 6 feet, winds increased to 40 knots and visibility was reduced to 328 feet.

Links :
  • Facebook : Perth Weather Live : Onslow dust storm photos
  • DailyMail : Skipper, turn this thing around! Incredible wall of sand whipped up by cyclone hits remote stretch of Western Australia coast

Saturday, January 12, 2013

Vendee Globe : Trindade and Martin Vaz

Situation January 12, 2013 11:00 UTC 

>>> geolocalization with the Marine GeoGarage <<<

The islands of Trindade (occasionally called Trinidad) and Martim Vaz (also called Martin Vaz) are located about 1,200 kilometers (740 mi) east of Vitória in the Southern Atlantic Ocean, belong to the State of Espírito Santo of Brazil.
They are considered part of the area of the state capital, Vitória.
The islands are uninhabited, except for a garrison of the Brazilian Navy, 32 strong.
The group consists of Ilha Trindade, by far the largest island, and Ilhas de Martim Vaz, 29 miles further east.

Clearer view of the island
(photos Marcelo Koelho)

 >>> geolocalization with the Marine GeoGarage <<<
Trindade is the largest island, with an area of 10.1 km² (3.9 sq mi); 

Martim Vaz

  >>> geolocalization with the Marine GeoGarage <<<
Note : the shift between the position of the DHN nautical chart and the Google imagery
about 49 km (30 miles) east of it are the tiny Martin Vaz islets.

The archipelago consists of five islands and several rocks and stacks.
The islands are of volcanic origin and have rugged terrain.
The island lies more than halfway between Brazil and the Mid-Atlantic Ridge near the eastern end of the submarine Vitória-Trindade Ridge.
The island is the main nesting site of the green sea turtle in Brazil.


They are largely barren, except for the southern part of Ilha Trindade.
They were discovered in 1502 by Portuguese explorer Estêvão da Gama and stayed Portuguese until they became part of Brazil at its independence.
From 1890 to 1896, Trindade was occupied by the United Kingdom until an accord with Brazil was reached.
During the period of British occupation, Trindade was known as “South Trinidad”.

Many visitors have been to Martim Vaz, the most famous of whom was the English astronomer Edmund Halley (of Halley’s Comet fame), who took possession of the island on behalf of the British Monarchy in 1700.
Captain La Pérouse stopped there at the outset of his 1785 voyage to the Pacific.

In 1893 the American James Harden-Hickey claimed the island and declared himself as James I, Prince of Trinidad.
According to James Harden-Hickey’s plans, Trinidad, after being recognized as an independent country, would become a military dictatorship and have him as dictator.
He designed postage stamps, a national flag, and a coat of arms; established a chivalric order, the “Cross of Trinidad”; bought a schooner to transport colonists; appointed M. le Comte de la Boissiere as Secretary of State; opened a consular office at 217 West 36th Street in New York; and even issued government bonds to finance construction of infrastructure on the island.
Despite his plans, his idea was ridiculed or ignored by the world.

In July 1895, the British again tried to take possession of this strategic position in the Atlantic.
The British planned to use the island as a cable station.
However, Brazilian diplomatic efforts, along with Portuguese support, reinstated Trindade Island to Brazilian sovereignty.

In order to clearly demonstrate sovereignty over the island, now part of the State of Espírito Santo and the municipality of Vitória, a landmark was built on January 24, 1897.
Nowadays, Brazilian presence is marked by a permanent Brazilian Navy base on the main island.

 (source : Aenigmatis)

On January 16, 1958, a unidentified flying object (refers as the Trindade Island's UFO) was seen and photographed over the Trindade Island.
The photographs were rumored as being a hoax.