What China has been building in the South China Sea

 From reef to island in less of one year
(Fiery Cross Reef)

Images by DigitalGlobe, via the CSIS Asia Maritime Transparency Initiative, 

and CNES, via Airbus DS and IHS Jane’s

From NYTimes by Derek Watkins

China has been feverishly piling sand onto reefs in the South China Sea for the past year, creating seven new islets in the region.
It is straining geopolitical tensions that were already taut.  

The speed and scale of China’s island-building spree have alarmed other countries with interests in the region.
China announced in June that the creation of islands — moving sediment from the seafloor to a reef — would soon be completed.
“The announcement marks a change in diplomatic tone, and indicates that China has reached its scheduled completion on several land reclamation projects and is now moving into the construction phase,” said Mira Rapp-Hooper, director of the Asia Maritime Transparency Initiative at the Center for Strategic and International Studies, a Washington research group.
 So far China has built port facilities, military buildings and an airstrip on the islands.
The installations bolster China’s foothold in the Spratly Islands, a disputed scattering of reefs and islands in the South China Sea more than 500 miles from the Chinese mainland.

Sources: C.I.A., NASA, China Maritime Safety Administration

The new islands allow China to harness a portion of the sea for its own use that has been relatively out of reach until now.
Although there are significant fisheries and possible large oil and gas reserves in the South China Sea, China’s efforts serve more to fortify its territorial claims than to help it extract natural resources, Dr. Rapp-Hooper said. 
The islands are too small to support large military units but will enable sustained Chinese air and sea patrols of the area.
The United States has reported spotting Chinese mobile artillery vehicles in the region, and the islands could allow China to exercise more control over fishing in the region. 

The Chinese were relative latecomers to island building in the Spratly archipelago, and “strategically speaking, China is feeling left out,” said Sean O’Connor, principal imagery analyst for IHS Jane’s.
Still, China’s island building has far outpaced similar efforts in the area, unsettling the United States, which sees about $1.2 trillion in annual bilateral trade go through the South China Sea.
At the end of May, Defense Secretary Ashton B. Carter criticized China’s actions in the region.  

Several reefs have been destroyed outright to serve as a foundation for new islands, and the process also causes extensive damage to the surrounding marine ecosystem.
Frank Muller-Karger, professor of biological oceanography at the University of South Florida, said sediment “can wash back into the sea, forming plumes that can smother marine life and could be laced with heavy metals, oil and other chemicals from the ships and shore facilities being built.”
Such plumes threaten the biologically diverse reefs throughout the Spratlys, which Dr. Muller-Karger said may have trouble surviving in sediment-laden water.  

 Image by DigitalGlobe, via CSIS Asia Maritime Transparency Initiative

What Is on the Islands?

South China Sea in the GeoGarage platform (NGA chart)

Vietnam, Malaysia, the Philippines and Taiwan have all expanded islands in the Spratlys as well, but at nowhere near the same scale as China. 

 Image by DigitalGlobe, via CSIS Asia Maritime Transparency Initiative

For China, the Fiery Cross Reef is the most strategically significant new island, with a nearly completed airstrip that will be large enough to allow China to land any plane, from fighter jets to large transport aircraft.
But China’s airfield is not the first in the region — every other country that occupies the Spratlys already operates one as well. 

 Image by CNES distributed by Airbus DS, via IHS Jane’s

China’s reefs hosted smaller structures for years before the surge in construction.

By preserving these initially isolated buildings, China can claim that it is merely expanding its earlier facilities, similar to what other countries have done elsewhere in the region. 

Image by DigitalGlobe, via CSIS Asia Maritime Transparency Initiative

China continues to expand islands at two locations, Mischief Reef and Subi Reef.

It is unclear what structures will be built on the islands, though each will have straight portions long enough for airfields. 

Image by DigitalGlobe, via CSIS Asia Maritime Transparency Initiative

Links :

• The Economist : Is China making the same mistakes as Japan did before the second world war?  
• WashingtonPost : What happens to a coral reef when an island is built on top?
• The Guardian : Preventing Ecocide in South China Sea 
• CSIS : Airpower in the South China Sea

What does the age of the survey mean for nautical charts?

 What are the differences between data collected in 1900, 1940, or 1960?

Let’s take a look at a…

From NOAA

Alaska’s nautical charts need to be updated — we all know that.
The diagram below shows the vintage of survey data currently used for today’s charts in Alaska.
The graphic includes all surveys done by NOAA’s Office of Coast Survey (and its predecessors), and some limited data acquired by other agencies, i.e., the U.S. Coast Guard.
Areas that are not colored in have never been surveyed or have data acquired by another source — from Russia or Japan, for instance — before the U.S. was responsible for charting in that area.

Brief Historical Sketch of Survey Technologies

Nautical charts have a lot of information, but mariners especially are concerned with two major components: water depths (known as “soundings”) and obstructions (like underwater seamounts or wrecks).
Different eras used different technologies to find, measure, and determine the position of the two components.
Note that adoption of new systems does not happen abruptly; rather, new technologies are phased in as techniques and equipment improves.

Measuring Water Depth (Soundings)

3.7 million years ago to present day: sounding pole
It isn’t inconceivable that the earliest humanoid, Australopithecus afarensis, used sticks to gauge water depths before crossing streams and rivers.
People still do it today.

 Note the ancient Egyptian on the far right, using a sounding pole.

~ 2000 B.C. to 1930s: lead line

As good as they were for their eras, 19th and 20th century surveyors faced technological challenges. The first challenge was accounting for gaps between depth measurements.
The second was the inability to be totally accurate in noting the position of the measurement.
(In other words, a specific location out in the ocean may be 50 feet deep, but a surveyor must also accurately note the position of that specific location.)

 This surveyor is casting a lead line.

Early Coast Survey hydrographers measured depths by lead lines — ropes with lead on one end — that were lowered into the water and read manually.
Even though soundings were generally accurate, coverage between single soundings was lacking. And we need to remember that this was before the age of GPS.
While sextants gave accurate positions when a hydrographer could fix on a shoreline feature, the further offshore the survey, the less accurate the position.

(Interesting fact: Hydrographers still use lead lines occasionally, in some circumstances — but not for a complete survey.)

There have been variations on lead lines through the centuries.
From 1492 to the late 1870s, for instance, mariners used hemp rope for deep-sea soundings.

(Interesting fact: Christopher Columbus and Ferdinand Magellan each tried to measure mid-ocean depths with about 1,200 feet of hemp rope. Neither one of them found the sea bottom.)

In 1872, the hemp was replaced by small diameter piano wire (again, primarily for deep-sea work), and the weight of the lead was increased.
Later, hydrographers added a motorized drum to wind and unwind the line, with a dial to record the length of the line.

(Interesting fact: In 1950, the British ship Challenger used piano wire in the first sounding that established Mariana Trench as the deepest place on earth.)

 20th century to the present: echo sounders

 Compare the bottom coverage achieved by the different survey methods.

1918 to 1990s: single beam echo sounder

Sonar came into its own in 1913.
The first echo sounders (also known as “fathometers”) had single beams that measured the distance of the sea floor directly below a vessel.
The echo sounders were able to take many more depth measurements than was possible with the lead line, but the technique still resulted in gaps between the lines where the beam measured the water depth.
The U.S. Coast and Geodetic Survey (a NOAA predecessor agency) adopted this acoustic sounding technique in 1923, installing it on USCGS Ship Guide.
But full-fledged change didn’t happen right away.
These early sounding systems were too large to install on survey launches used in harbor and inshore work, so from 1924 until the early 1940s many surveys were still conducted with a lead line, and many were totally acoustic — and some were hybrid, using soundings from both methods, depending on coverage area and seafloor configuration.
→ 1940: U.S. Coast and Geodetic Survey fully adopts single beam echo sounding technology
The development of smaller “portable” fathometers for shallow waters, about 1940, was a primary impetus in the obsolescence of lead line as survey technology and the adoption of acoustic systems.
The development of World War II electronic navigation systems for bombing purposes led to the development in 1945 of the first survey-quality electronic navigation systems, which allowed for more accuracy in positioning.

1964 to current day: multibeam echo sounder

By mid-century, scientists were increasing the beams projected by the echo sounder, to get a broader swath of measurements.
The multibeam echo sounder was developed for the Navy in 1964, but it remained secret until the late 1970s when commercially available systems were developed.
Coast Survey first used a MBES technique, called the “Bathymetric Swath Survey System,” in 1977 on NOAA Ship Davidson, for depths ranging from 160 to 2,000 feet.
In 1980, NOAA Ship Surveyor installed a deep-water MBES system called “Sea Beam,” for depths from 1,600 to 33,000 feet.
About 1986, Coast Survey began using GPS to calibrate medium-frequency navigation systems while operating in the far reaches of the United States Exclusive Economic Zone.
By the mid-1990s, GPS was the primary control for accurate positioning.
→ 2000: Coast Survey fully adopts multibeam surveying
By 2000, Coast Survey was performing full-coverage multibeam hydrographic surveys for charting purposes.
NOAA survey ships now use multibeam echo sounders that measure navigable coastal depths from 45 to 1,000 feet.
For shallower and more constricted waters, the ships deploy hydrographic survey launches with multibeam echo sounders that efficiently and safely survey areas from 12 to 200 feet deep.
These systems make it possible to acquire 100% sea floor coverage in the survey grounds (excluding ultra-shallow, near-shore, or obstruction areas).

Finding Underwater Obstructions

1880s to early 1990s: wire drag

Surveyors used wire drag, not as a sounding system but as a way to look between the sounding lines to find obstructions to navigation and establish safe navigational channels.
The first documented wire drag was conducted in the 1880s, in French Indochina, Gulf of Tonkin area, attaching the wire to buoys at each end and letting it drift with tidal currents.
Around 1900, the U. S. Lake Survey developed the technique of using a ¼-mile wire drag between two boats.
In 1903, Coast Survey began using the technique, and within a few years was using it extensively in Alaskan waters as they looked for pinnacle rocks.
Coast Survey’s Alaska wire drags were up to 3.5 miles long.
(Initially, “least depths” over discovered obstructions were determined by lead line, then acoustic means and, ultimately, by divers with depth/pressure gauges.)

 Survey vessels conduct wire drag operations.

1960 to present day: side scan sonar

Side scan sonar is essentially the sonar equivalent of an aerial photograph.
It improves the ability to identify submerged wrecks and obstructions.
Evolving from submarine detection sonars of World War I and World War II, side scan sonar was fairly well developed by 1960, when the United Kingdom Hydrographic Office started using it regularly with their surveys.
→ 1990: Coast Survey fully adopts side scan sonar for East Coast and Gulf Coast surveys
NOAA Ship Whiting used the technology in 1984-1985 for approaches to New York. U.S. Coast Survey fully adopted side scan sonar (in place of wire drag) in the early 1990s.

 Side scan sonar operations use “towfish” like this one, lowered into the water and towed from the back of the vessel.

 Side scan sonar captures images of objects, which improves the ability to identify submerged objects.

Today’s Charts Reflect Different Tech Eras

Each of NOAA’s 1000-plus nautical charts, even today, can contain information collected by any or all of these sounding and positioning techniques.
Most nautical charts are an amalgamation of geospatial information collected using different techniques at different times.
For example, one area of a specific current-day nautical chart might be based on a lead line and sextant survey conducted in 1910, and another area on the same chart might be based on a multibeam and GPS survey conducted in 2010.
If we dig deep enough, we will probably find a sounding or two from the 18^th century British explorer, Captain James Cook.
NOAA cartographers mold this disparate information so that it fits together as a coherent representation of the geographic area.
So when was the data acquired for the chart you’re using?
NOAA cartographers add a “source diagram” to large-scale charts.
(See the diagram on the current chart 16240, pictured below.)
Check yours.
That will give you the years of the surveys… and now you have a better idea on the technology used by the surveyor.

 This is the source diagram on nautical chart 16240.

 16240 chart in the GeoGarage platform

The search for Malaysia Airlines Flight 370 : debris discovery 'consistent with ocean currents from search area'

Possible MH370 clue rode ocean currents

Here's how wreckage from Malaysia Airlines Flight 370 could have floated thousands of miles away from the search area off the coast of Australia

 From Reuters by Lincoln Feast and Jeffrey Dastin

Vast, rotating currents sweeping the southern Indian Ocean could have deposited wreckage from a missing Malaysia Airlines passenger jet near Africa, thousands of kilometres from where it is thought to have crashed, oceanographers said on Thursday.

French authorities are studying a piece of plane debris found on Reunion Island, off the east coast of Madagascar, to determine whether it came from Flight MH370, which disappeared without a trace 16 months ago with 239 passengers and crew on board.

If confirmed to be part of the missing Boeing 777, experts will try to model its drift to retrace where the debris could have come from, although they cautioned it was unlikely to help in narrowing down the plane's final resting place beyond the vast swathe of ocean off Australia that has been the focus of the search for months.

"This wreckage has been in the water, if it is MH370, for well over a year so it could have moved so far that its not going to be that helpful in pinpointing precisely where the aircraft is," Australian Deputy Prime Minister Warren Truss told reporters.
"It certainly would suggest the search area is roughly in the right place."

Australia has been leading a search for the plane since analysis of a series of faint satellite "pings" from the aircraft led investigators to conclude that it crashed in the stormy southern Indian Ocean about 2,000 km southwest of Perth.

Ocean current models

Models of ocean currents were consistent with the potential discovery of debris in the tropics, roughly 3,700 km to the northwest, oceanographic experts said.

A huge, counter-clockwise current, called a gyre, covers much of the southern part of the 70.5 million sq km (27.2 million sq miles) Indian Ocean, running east along the Southern Ocean near Antarctica, up the west Australian coast and westward below the equator towards Reunion and Madagascar, before turning south.

 Marked by the green circle, Reunion Island is visible in this map highlighting the complexity of eddies and gyres in the Indian Ocean.
Embedded in overall broad ocean currents are small eddies that create turbulence and make it complicated to track the flow of potential debris.

source : earth.nullschool.net
 

On the basis of the aircraft debris that was found on 29 July on the island of Réunion, hydrodynamic experts of Deltares produced a simulation model that indicates that the northern part of the search is now a more likely source of the debris.

Debris tracking flight MH370 based on ocean currents

Deltares experts Maarten van Ormondt and Fedor Baart used a particle tracking routine to compute the movement of debris from different locations in the search area.

The calculation was made using surface currents (assuming that they are the most relevant for the floating debris) from the global HYCOM model.

The results show how debris moves with the counter-clockwise gyre in the Southern Indian Ocean and quickly disperses over large areas.

Particles released in the northern section of the search area arrive at the African coast first within a year of the release time.

Those released in the southern section do not travel as far and do not make it to Africa within the simulation period.

 Average surface currents since the disappearance of MH370. Colors have been Zissoufied and indicate current speed. Arrows show current direction and larger arrows = faster currents.

source : Dr Martini

 Ocean currents in the search area : shows the east to west flow of the Indian Ocean gyre, one of five such major surface currents on Earth. 

Maarten van Ormondt (a Deltares hydrodynamic expert): ‘The model shows us that the ocean currents are able to carry the debris from the search area west of Australia to Réunion. It also suggests that it is more likely that the debris originates from the northern section of the search area than from the southern part.”

Erik van Sebille, an oceanographer at Imperial College London, said that, if the debris on Reunion was indeed from MH370, his modelling suggested the aircraft went down in the north of the search zone.
"This westward drift from near Australia all the way across the Indian Ocean can really only happen if the plane went into the water relatively close to the equator," he said.
Finding more debris would help triangulate where MH370 may have hit the water, he added.

 Another computer model developed by Erik van Sebille, an oceanographer at the Imperial College in London, uses historical ocean currents data to predict the probable paths that objects could take drifting through the ocean over the course of several months.

This map shows the model's predictions for an object washing up on the island of Réunion.

Pattiaratchi's modelling shows debris could also drift also as far east as Tasmania or beyond.
"Our model results that we did last year predicted that within 18-24 months after the crash, it was a possibility that it would have ended up within that region," said Charitha Pattiaratchi, Professor of Coastal Oceanography at the University of Western Australia.
The point of origin "will definitely be in the Southern Hemisphere, it would be to the east, it would cover definitely the area of the physical search at the moment", he added.
That physical search, now halfway to being completed, covers 120,000 sq km of sea bed.

 Oceanographers created this chart one year ago showing the potential drift of MH370, starting from the Indian Ocean search zone.
Scientists at The University of Western Australia say there is a consistency between the current search area at Reunion Island and where debris from missing Malaysian Airlines flight MH370 could have drifted to, based on their research.
source : UWA 

Barnacle clues

Dave Gallo, who co-led the search for Air France Flight 447 that crashed in the Atlantic Ocean in 2009, warned that retracing the debris' drift through sea-current models could lead investigators astray.

"Retro-drifting" from wreckage found just five days after the Air France crash led to no breakthrough, he said.
"We spent two months in that area and found absolutely nothing. That brought mistrust from the industry," said Gallo, director of special projects at the Woods Hole Oceanographic Institution. "Looking at something that is 500 days old is going to be tough."

France's BEA crash investigation agency raised questions in 2012 over the reliability of such "reverse drift" calculations after conducting tests during the search for AF447.
It had asked the French Navy to drop nine buoys at a single spot in the Atlantic, only to find they scattered hundreds of miles apart, highlighting the "great difficulty" of predicting drift.

Experts say such divergences can increase over time.

Still, further clues might yet come from the debris.

Experts can age the barnacles that attach themselves to flotsam, which would give an idea of how long it had been in the water.

They may even be able to tell which part of the ocean it has come from by the species of barnacles attached.
"There's different barnacles in different parts of the ocean, so you might expect some CSI scenario where just by looking at the barnacles, you can pinpoint where it came from," van Sebille said.

 

Links :

• NYTimes : Search for flight 370
• The Guardian :  M370 possible breakthrough debris found Reunion island 
• CNN : MH370: Takeoff, disappearance, searches ... and possible debris found
• Gov.uk : UK government offers support to narrow down the search for MH370
• WP (2014) : “Roaring Forties” winds, gyrating ocean currents pose Malaysia plane search nightmare
• GeoGarage blog : Why locating MH370 in the Southern Ocean is so difficult 

Rolling the Deep - Papua New Guinea

Rolling in the Deep - Eastern Papua from Dustin Adamson

Eastern Papua New Guinea is one of the last unspoiled diving destinations in the world.
The diversity of life in this region is staggering.

Rolling in the Deep - Papua New Guinea from Dustin Adamson

This episode of the Rolling the Deep series focuses on the small critters of the area.
The colors and textures of these animals is an amazing and beautiful sight.

Enjoy! 

Nudibranchs of Papua New Guinea from Dustin Adamson

Nudibranchs are generally small, a bit like a traditional slug.
But these slugs are much more interesting that the ones we find in the garden.
The different shapes, colors, and sizes make each species of nudibranchs unique.
Hopefully with this video that is up close and personal with the nudi's, you gain the appreciation for their beauty.

First flights off Lorient

A genuine test laboratory, in the space of six months the Multi70 Edmond de Rothschild has become the perfect guinea pig for Gitana Team’s design office.
After an initial research phase involving T-foil rudders, which was validated by Sébastien Josse’s third place in the Route du Rhum 2014, it’s now time for the second phase of development.
Equipped with asymmetric foils (L-foil to port and C-foil to starboard) and new, more substantial T-foil rudders, the 2015 version of the trimaran fitted out by Baron Benjamin de Rothschild is undergoing her first sea trials offshore of Lorient; the first flights in real conditions."