Saturday, May 30, 2015

Earth's magnetic declination

The magnetic poles (indicated by green circles) slowly move with time.
The magnetic declination varies with time due to changes of the Earth's magnetic field.
Since the 1970's the Magnetic North Pole has accelerated from less than 10 to more than 30 miles per year


Earth is like a giant magnet with a North and South Pole.
However, the magnetic North and South Pole are not aligned with the Geographic North and South Pole.
The Geographic North Pole is defined by the latitude 90° N and is the axis of the Earth's rotation.
The Magnetic North Pole is where the Earth's magnetic field points vertically downward.
The Earth creates its own magnetic field from the electric currents created in the liquid iron-nickel core.
Compass needles point in the direction of the magnetic field lines, which is generally different from the direction to the Geographic North Pole.
The compass pointing direction can also differ from the direction to the Magnetic North Pole since the magnetic field lines are not just circles connecting the magnetic poles.

 1700 map of declination (compass variation) maybe first use of isolines ?

This dataset shows lines of equal magnetic declination (isogonic lines) measured in degrees east (positive) or west (negative) of True North.
The green line is where the declination equals zero and the direction of True North and Magnetic North are equal (agonic line).
The Magnetic North and South Poles are indicated by the green circles.

World Showing the Lines of Equal Magnetic Declination (1896)

It is important to know the magnetic declination when using a compass to navigate so that the direction of True North can be determined.
Since the 1970's, the movement of the Magnetic North Pole has accelerated, which is noticeable in this dataset.
In this figure and animation, the magnetic field from 1590 to 1890 is given by the GUFM-1 model of Jackson et al. (2000), while the field from 1900 to 2015 is given by the 11th generation of the International Geomagnetic Reference Field.
Between 1890 and 1900, a smooth transition was imposed between the models.
This visualization uses a transverse aspect of the Plate Carrée projection to minimize distortion near the poles.

Links :

Friday, May 29, 2015

Researchers measure giant "internal waves" that help regulate climate

This animation shows density layers in the South China Sea being perturbed by the regular back-and-forth tidal flow through the Luzon Strait.
These leads to large amplitude internal waves (shown in red underwater, and in white when seen from above), being radiated west to the Chinese continental shelf.

From Phys

Once a day, a wave as tall as the Empire State Building and as much as a hundred miles wide forms in the waters between Taiwan and the Philippines and rolls across the South China Sea – but on the surface, it is hardly noticed.

Simulation of internal waves of the South China Sea by Dr. Harper Simmons of the University of Alaska Fairbanks using Arctic Region Supercomputer Center High Performance Computing resources. Visualization by the University of Washington Center for Environmental Visualization).

These daily monstrosities are called "internal waves" because they are beneath the ocean surface and though scientists have known about them for years, they weren't really sure how significant they were because they had never been fully tracked from cradle to grave.

Surprisingly, internal waves can sometimes be seen clearly in satellite imagery (like in the above image of the Luzon Strait).
This is because the internal waves create alternating rough and smooth regions of the ocean that align with the crest of the internal wave.
Sunlight reflects the smooth sections, appearing as white arcs, while the rough sections stay dark.

But a new study, published this week in Nature Research Letter, documents what happens to internal waves at the end of their journey and outlines their critical role in global climate.
The international research project was funded by the Office of Naval Research and the Taiwan National Science Council.

"Ultimately, they are what mixes heat throughout the ocean," said Jonathan Nash, an Oregon State University oceanographer and co-author on the study. "
Without them, the ocean would be a much different place.
It would be significantly more stratified – the surface waters would be much warmer and the deep abyss colder.
"It's like stirring cream into your coffee," he added. "Internal waves are the ocean's spoon."

Internal waves help move a tremendous amount of energy from Luzon Strait across the South China Sea, but until this project, scientists didn't know what became of that energy.
As it turns out, it's a rather complicated picture.
A large fraction of energy dissipates when the wave gets steep and breaks on the deep slopes off China and Vietnam, much like breakers on the beach.

Researchers from the Office of Naval Research's multi-institutional Internal Waves In Straits Experiment (IWISE) -- including from Princeton University -- have published the first 'cradle-to-grave' model of internal waves, which are subsurface ocean displacements recognized as essential to the distribution of nutrients and heat. The researchers modeled the internal waves that move through the Luzon Strait between southern Taiwan and the Philippine island of Luzon. Credit: Maarten Buijsman, University of Southern Mississippi

Read more at:
Researchers from the Office of Naval Research's multi-institutional Internal Waves In Straits Experiment (IWISE) -- including from Princeton University -- have published the first 'cradle-to-grave' model of internal waves, which are subsurface ocean displacements recognized as essential to the distribution of nutrients and heat.
The researchers modeled the internal waves that move through the Luzon Strait between southern Taiwan and the Philippine island of Luzon.
Credit: Maarten Buijsman, University of Southern Mississippi

But part of the energy remains, with waves reflecting from the coast and rebounding back into the ocean in different directions.
The internal waves are caused by strong tides flowing over the topography, said Nash, who is in OSU's College of Earth, Ocean, and Atmospheric Sciences.
The waves originating in Luzon Strait are the largest in the world, based on the region's tidal flow and topography.
A key factor is the depth at which the warm- and cold-water layers of the ocean meet – at about 1,000 meters.
The waves can get as high as 500 meters tall and 100-200 kilometers wide before steepening.
"You can actually see them from satellite images," Nash said.
"They will form little waves at the ocean surface, and you see the surface convergences piling up flotsam and jetsam as the internal wave sucks the water down. They move about 2-3 meters a second."
The graph above shows the band-passed semidiurnal baroclinic energy flux magnitudes.

The waves also have important global implications.
In climate models, predictions of the sea level 50 years from now vary by more than a foot depending on whether the effects of these waves are included.
"These are not small effects," Nash said.

This new study, which was part of a huge international collaboration involving OSU researchers Nash and James Moum – as well as 40 others from around the world – is the first to document the complete life cycle of these huge undersea waves.

The complexity of the Luzon Strait's two-ridge system was not previously known.
The Princeton researchers' simulations showed that the two ridges of the Luzon Strait greatly amplify the size and energy of the waves, well beyond the sum of what the two ridges would generate separately.
The simulation above of the tide moving over the second, or western, ridge shows that the tidally-driven flow reaches a high velocity (top) as it moves down the slope (left to right), creating a large wave in density (black lines) with concentrated turbulent energy dissipation (bottom).
As the tide moves back over the ridge, the turbulence is swept away.
For both the velocity and energy dissipation panels, the color scale indicates the greatest velocity or energy (red) to the least amount (blue).
Credit: Image by Maarten Buijsman, University of Southern Mississippi

Links : 

Thursday, May 28, 2015

The new Silk Road: A visionary dream for the 21st century

From Forbes by Jean-Pierre Lehmann

The New Silk Road may be the dream to inspire coming generations.
This seems all the more the case when set in the historical context of the last half-century.
If it were to become reality, it could be a major inspirational epochal game-changer.
Whether it’s a dream or a nightmare depends in great part on the spirit with which the opportunity is seized and the challenge tackled.

The past golden years

When British Prime Minister Harold MacMillan made his speech on 20 July 1957 saying “You’ve never had it so good”, he was right.
I was 12 years old then and life and its prospects, for a Western European adolescent, did seem good and promising.
Of course I was conscious that it was not like that everywhere.
The year before, 1956, there had been the Hungarian Uprising and its brutal suppression (including the killing of children my age) by Soviet troops.
But as a Western European I realize that ours is the luckiest generation ever.
My grand-father was in World War I, my father in World War II, my mother a refugee from the Spanish Civil War, they experienced the depression, the rise of extremist ideologies, genocide, along with all the other dreadful things that happened.
My generation got peace, prosperity and instead of European War, the European Union.
Not only was the West a far better place than it had been, but things seemed to keep getting better; it was an age of optimism.
In the early 1960s I was living in Washington DC, where racist bigotry pervaded the city and the country; on 28 August 1963, the day before my 18th birthday, Martin Luther King’ gave his famous “I have a dream” speech; it ignited and inspired a whole generation.
Along with the struggle against racism in the West, there was the struggle against sexism, for women’s liberation.
Yes, there was hatred and ugliness, but, as in the lyrics of the famous song of that era, we knew that “We Shall Overcome“.
There was bleakness in the 1970s, including the oil crises, unemployment and inflation soaring, terrorist movements such as the Baader Meinhof in Germany, the Rengo Sekigun and the (Charles) Manson Family in the US.
These were to some extent counterbalanced by a number of more positive developments.
With the deaths of their respective dictators, Salazar and Franco, Portugal and Spain renounced their military dictatorships and embraced democracy.
At the other end of the planet, the Cultural Revolution ended in China, Mao Zedong died and the economic reform program was about to be launched.
If the era were put to a symphony, the grand finale, with drums, cymbals, French horns and the entire orchestral works, molto giojoso, would come in the early 1990s, following the fall of the Berlin Wall, the collapse of the Soviet Union and its empire, the end of apartheid in South Africa, reforms and opening up in India, the establishment of the World Trade Organization, continuing opening of China, reforms in Vietnam, democratization in South America, also in Korea and Taiwan, etc, etc!

The dark years

However, the euphoria of the end of the last century has been followed by disillusionment, or worse, in this century.
There continue to be good things happening, but the overall global ambience is depressing and the outlook discouraging.
Youth unemployment has soared pretty much everywhere, the looming threat of climate change is, well, left to loom, the US and China seem more headed to confrontation rather than collaboration, as the sequels of the catastrophic UK-US invasion of Iraq not only linger, but fester, the situation in the Levant is dramatic, we have the terrible tragedy of the Rohingyas, the many deaths of refugees in the Mediterranean, the consequences of the global financial crisis, the rise of populist parties, the resurgence of nationalism, the cynicism and criminality of too much of the finance industry, and perhaps above all in lieu of the optimism that pervaded my generation, growing pessimism and fatalism among the coming generations.
So I’m ok. I will have had a very good and lucky life.
But I worry for my grandchildren.
And I worry all the more because I do not have sufficient confidence that our business and political leaders, obsessed by cynical egotistical material short-termism are concerned about the next generations.
What kind of planet do we want to leave behind?

The past and future promise of the New Silk Road?

It is in this context that ever since the announcement of its launching I have been intrigued by the vision of The New Silk Road – or, to give it its full rendition, The New Silk Road Economic Belt and 21st Century Maritime Route.
I have since followed developments closely; I was privileged to attend in December last year a meeting in Qianhai (Shenzhen), jointly organized by the Qianhai Institute for Innovative Research (QIIR) and the Italian Ambrosetti Group, on the 21st century Maritime Silk Road, and with my great and dynamic class at Hong Kong University this last month we have had wide-ranging, intensive and stimulating conversations on the subject.
I shall also be presenting findings at a major annual event, Orchestrating Winning Performance, at IMD, in Lausanne (Switzerland), next month.
It is a fascinating prospect at every level.

The Silk Road and its maritime Spice Route (see above) lie at the origins of globalization not only in the transmission of goods, but in the transmission of ideas, knowledge, culture, religions, science and technology.
The Silk Road lasted and flourished from the first century BCE until the mid-15th century, challenged and ultimately superseded by the rise of the Portuguese seaborne empire.
The Spice Route was initially mainly the preserve of the Arabs, its point of departure was in Indonesia, which it will also be for the New Maritime Silk Road: spices were the first globally traded product.
The legacy of the Silk Road in history is enormous as it is in art, literature, science and architecture.
The Great Colonnade in Palmyra, Syria, that ISIS (the Islamic State of Iraq and the Levant) threatens to destroy, is one of the multiple grandiose and awe-inspiring examples, as is the Kalyan Minaret and Mosque in Bukhara, Uzbekistan (see illustration below).
In Europe, Venice was a major destination for the merchants of the Silk Road, hence of the prosperity and beauty of La Serenissima, as Venice is called; the plan for the 21st Century Maritime Silk Road is also to make Venice a key destination.

Of course the Silk Road and the Spice Route of the past were very much about money.
There was a pecuniary goal.
But the cultural wealth that was generated was immense.
Global civilization would be much the poorer without it.
The historical Silk Road is a major source of inspiration, wonder and dreams.
Can the 21st century Silk Road be anything of the sort?
The answer to that question all depends on how political, business and thought leaders approach and develop the opportunity.
Looking at the project it is clear it includes (of course) economic objectives on the part of he Chinese, and it is also clear it has a geopolitical dimension in the context of the US-China rivalry.
But if it is adopted as a global project it could also provide a great and dynamic fillip to the global mood and activity.
The fact that 57 countries chose to defy Washington and become founding members of the Asian Infrastructure Investment Bank (AIIB), the financial institution behind the New Silk Road, is an encouraging sign: among major potential members only Canada, Japan and the US chose to stay out.
So it already is a global, or certainly trans-Eurasian project.
There is the engineering feat it will represent.
It will re-engineer the planet much in the same way as the railroad did in the 19th century – something which was also a source of dreams and wonder beyond just the mundane bit of going from A to B.
Remember, among others, the Orient Express (see illustration below)!
It will include regions, Western China and Central Asia – Afghanistan, Turkmenistan, Uzbekistan, Kazakhstan, Kyrgyzstan, Iran, Iraq and Syria – that were hubs of globalization at the time of the Old Silk Road, but in more recent times have been marginalized, described as the “orphans” of globalization.
The New Silk Road might give would-be Jihadists other more constructive dreams to pursue than their current destructive nihilistic fanaticism.
With the current forces of de-globalization threatening the prospects of future global prosperity and peace, the New Silk Road might give a boost to re-globalization.

The New Silk Road and Maritime Route can bring about the reintegration of the Eurasian continent. The potential boost for an increasingly inward-looking and morose Europe is enormous.
While the New Silk Road encompasses three continents – Asia, Africa and Europe – for the moment the “new world” of the Americas does not feature.
A compelling recent publication by Germán Muñoz, President of the Mexican Chamber of Commerce in Hong Kong, proposes how the New Silk Road might link up with another historic global route, the Ruta de La Plata, which served as the conduit for the transport of Mexican silver (the international currency of the time) to Asia from the 15th to the 19th centuries, arguing that: “History can provide lessons for the future, and the legacy of La Ruta de la Plata has great potential – and not just in trade itself. It also provides a template, as do the Silk Roads, for enhanced multilateral cooperation, regional development and integration of Asia and Latin America.”

The New Silk Road is not a given.
There are pitfalls.
But the prospects are also mind-boggling.
It behooves the world, especially the major powers, to tackle the challenge with enthusiastic clear-eyed determination.
It is the kind of visionary dream that could inspire the next generations … including my seven grand-children!

Links :

Wednesday, May 27, 2015

Troubled waters: the South China Sea dispute

OVER THE SOUTH CHINA SEA (May 20, 2015) Sailors assigned to Patrol Squadron (VP) 45 conduct flight operations aboard a P-8A Poseidon over the South China Sea.
During the flight, the crew of the P-8A documented several warnings, issued by China’s People's Liberation Army Navy (PLAN), to leave the area.
The mission documented the continued expansion of reefs which have been turned into man-made islands with airport infrastructure in the South China Sea. VP-45 is on deployment supporting U.S. 7th Fleet operations in the Pacific. (U.S. Navy video/Released/)
other video : AirSource

From Euronews

With the world distracted by seemingly more immediate stories of war, migration and elections, a spat between the US and China wasn’t exactly headline news for many.
It happened earlier this month (May) when a US spy plane flew over disputed territory in the South China Sea, prompting a strong exchange between Beijing and Washington.

Some believe arguments over the contested waters could descend into a military conflict.

Why is the South China Sea so important?

In short, money.
Half of the world’s commercial shipping passes through the sea en-route from Europe and the Middle East to East Asia.

South Sea China ENCs in the GeoGarage platform

Trade value is put at $5 trillion (4.58 trillion euros) every year, according to Reuters.
But, perhaps more importantly, it is believed there are huge oil and gas reserves beneath the seabed.
The World Bank says the South China Sea has oil reserves of at least seven billion barrels and an estimated 900 trillion cubic feet of natural gas.
This could provide China’s growing economy with energy security but is also of huge potential for smaller countries like Malaysia and Vietnam.

Who claims ownership of the South China Sea?

The sea, which covers 3.5 million square kilometres, borders so many countries: Malaysia, Brunei, the Philippines, Vietnam, Taiwan, and, of course, China.
China says nearly the whole sea belongs to it, contradicting competing claims from several other Asian nations including Vietnam, Taiwan, Malaysia, Brunei and the Philippines.
China’s neighbours – and the US – fear Beijing will use the newly-created facilities for military use, cementing their claims over the sea.

 Country claims to South China Sea, shown in grey 

Why is tension building?

Tensions escalated when satellite images emerged in April appearing to show China building an airstrip on the Spratly Islands, a disputed territory.

 Airbus Defence and Space imagery shows ongoing construction at Fiery Cross Reef in the South China Sea.
The runway, approximately 3,000 metres long, will be able to handle all Chinese military aircraft when completed.
(CNES 2015, Distribution Airbus DS / IHS)

The construction work on reclaimed land can accommodate a runway around 3,000 metres long, according to a report published in IHS Jane’s Defence Weekly.
There has also been claims China was building airstrips on Johnson South Reef in the Spratlys and Woody Island in the Paracel Islands.

 Chinese dredging vessels around Mischief Reef in the disputed Spratly Islands, shown in a surveillance image. The work has led to tensions with China's neighbors. (US Navy)

On Tuesday (May 26), China outlined a strategy to boost its naval reach in the region, saying it would go on the offensive if required.
It also unveiled two lighthouses in disputed waters, something likely to increase tensions further.

What happens next?

Taiwan put forward a peace plan on Tuesday (May 26) aimed at reducing tensions between China and its neighbours and the US.
President Ma Ying-jeou called on those involved to shelve their disagreements and start talking about sharing resources.
Launching initiative, Ma urged a peaceful resolution “before a major conflict breaks out.”
Taiwan normally maintains a low key approach to such issues, but has coast guard and military facilities in the area.
They include an airstrip and soon-to-be-completed port on Taiping Island, also known as Itu Abu, the largest natural land mass in the disputed Spratlys archipelago.
Ma’s plan is similar to that proposed for the East China Sea, which opened the way for Taiwan and Japan to jointly fish in the contested waters.

How serious could it get?

Launching Taiwan’s peace initiative, Ma urged a peaceful resolution “before a major conflict breaks out.”
Hua Chunying, a spokesman for China’s foreign ministry, said: “We believe Chinese people on both sides of the Strait have a duty to jointly protect China’s territorial sovereignty and maritime rights and interests and safeguard the stability of the South China Sea region.”

Links :

Tuesday, May 26, 2015

New maps reveal California’s sensational seafloor geography

The topography of the ocean floor in the Golden Gate area of the San Francisco Bay. USGS

From Wired by Betsy Matson

An unprecedented effort to map the seafloor bordering California’s coastline has produced some of the most detailed, beautiful and useful maps of an underwater landscape ever made.

Virtual fly-through over the seafloor of Central California near San Francisco as if the water was drained from the ocean.
The movie flies out of San Francisco Bay pausing over a field of large sand waves west of the Golden Gate, and then up to the Bolinas area revealing folded and fractured bedrock.
The movie then turns south flying down the coast past Pacifica and towards Half Moon Bay again revealing folded and fractured bedrock beneath the Maverick's surf break.
The movie finishes by flying over very complex seafloor of folded bedrock, fault scarps, and ripple scour depressions south of Half Moon Bay and offshore San Gregorio State Beach.
The seafloor is colored for depth with reds and oranges representing shallower regions and dark blues and purples representing deeper regions.  (USGS)

No fewer than 18 state and federal agencies and institutions led by the US Geological Survey banded together to make these maps.
A staggering amount of work went into the California Seafloor Mapping Program, and the results are impressive.

 Data integration and visualization, Offshore of San Francisco map area
by Peter Dartnell (USGS)

“Nowhere else in the world are people pursuing comprehensive seafloor mapping at this scale,” said USGS geologist Sam Johnson, the agency’s lead scientist on the project.
“It’s really unprecedented globally.”

 A map of seafloor character in the Golden Gate area of the San Francisco Bay. USGS

The maps could be important for studying things like navigation safety, coastal erosion and sea level rise, fisheries, and earthquake and tsunami hazards.
The maps have already yielded a ton of new information for scientists, along with a few surprises.
For example, in Bodega Bay, the San Andreas fault is actually located about 800 meters away from where it was thought to be.

 Sand waves mapped on the seafloor, looking to the southeast over the entrance to San Francisco Bay. The Golden Gate bridge is to the east (left) of this view. USGS

The scale of the project, started in 2007 by the California Ocean protection Council, is staggering.
For 83 blocks of seafloor, each stretching 3 nautical miles from the shoreline, ten different maps are being made of the bathymetry (underwater topography, as seen in the color shaded-relief map of San Francisco Bay at the top of this post), geology, and ocean floor biological habitats.
The maps are based on a wide range of data collected since 2007, including swath sonar data, acoustic backscatter, seismic-reflection profiles, seafloor photos and video, and samples of the seafloor sediment.
Pretty much the only thing they didn’t use are the Navy’s trained dolphins.
All the data collection and mapping has been completed, and the USGS is in the process of releasing the maps and related reports to the public.
Today the maps for the Bay Area, Tomales Point, and Drakes Bay were published.
A total of 12 blocks have been released to date, and Johnson expects the next ten to be available by October.

 Geology of the San Francisco region

Sensational Geography

If your first reaction to these maps is an urge to print them out and hang them on your wall, you’re not the only one.
Johnson says the map of offshore San Francisco shows off some “sensational geography,” including a deep scour pool beneath the Golden Gate, the first detailed mapping of the Bay’s sand waves and an offshore sand bar known as the Potato Patch.
Maps of the geology below the surface down to 100 meters reveal a big paleochannel through which the Sacramento River flowed around 21,000 years ago when sea level was about 125 meters lower.
But in addition to being very cool to look at, the maps contain a lot of potentially important detail.
Johnson’s group at the USGS studies earthquake and tsunami hazards and is working on producing maps that show in detail where the offshore faults are.
For the first time, they can see precisely how long offshore faults are and whether they are connected to each other.

 Marine habitats mapped along the seafloor near Tomales Point

This kind of information is critical because the magnitude of an earthquake is determined by the length of a fault that ruptures. Longer faults are capable of bigger quakes. If two smaller faults that were thought to be separate are actually connected, they could potentially rupture together to cause a bigger earthquake than previously thought. Discoveries of that sort could even change the USGS’s seismic hazard forecast for California.
One place the data is already leading to new discoveries is near the Diablo Canyon nuclear power plant in central California.
Johnson’s team has identified previously unknown faults and new connections between faults, findings that will influence the current understanding of the seismic risk in the vicinity of the controversial power plant.
Johnson’s team is also looking for evidence of underwater landslides, which can be triggered by earthquakes.
Evidence of past slides and sites with similar characteristics could help identify where landslides big enough to generate local tsunamis are likely to occur.
The scientists have also found evidence for ground failure significant enough to wreak havoc on offshore infrastructure on surprisingly gentle slopes, even ones as shallow as 1 degree.

 Geology in the Refugio State Beach region where an oil spill occurred on May 19, 2015.

The maps show an unwelcome dearth of sediment along the San Francisco peninsula.
This is because such a narrow strip of land doesn’t provide large drainage areas to deliver sediment to the seafloor.
And while this isn’t unexpected, it is troubling.
Naked seafloor is a lot more vulnerable to being eroded by ocean currents than seafloor that is covered in a deep blanket of sediment.
And this problem is only going to get worse, because as sea level rises, more and more of the California coastline will be threatened by erosion.
There are three ways massive coastal erosion is being handled in other areas, Johnson says.
You can just let the coastline retreat and relocate infrastructure further inland, which is expensive and not practical or even possible in some coastal areas.
You can build jetties and groins, but this causes a whole new set of problems and introduces huge, unnatural structures into the marine environment.
Or you can bring in sediment from adjacent areas that have more of it, and stall the erosion.

 Sediment depths in Drakes Bay
Mapping sediment thickness, as shown on the map below, is important for this strategy.
And the lack of sediment along the San Francisco peninsula means this method may not be an option. “It was an unknown,” Johnson said.
“Nobody had mapped the distribution of sediment thickness before like we have on these maps.”
One of the most important things these new maps do is create a detailed snapshot of California’s coastline as it exists today, Johnson says.
This gives scientists a baseline they can use to monitor how things change.
The high-resolution data could be particularly useful in evaluating the effects of accidents like the oil spill that hit the Santa Barbara coastline at Refugio State Beach just three days ago.

Monday, May 25, 2015

US NOAA update in the GeoGarage platform

Coral bleaching animation

 Zoom into a coral reef and discover photosynthetic algae inside the coral’s cells.
Reef-building corals rely on these symbionts for their survival.

Sunday, May 24, 2015

Surfing and sailing from above

l'Hydroptère from Kai Concepts Team