Sunday, February 9, 2014

Earth's magnetic field : lesson from ESA


An introduction to Earth's magnetic field: what it is, where it comes from and what it's used for.


Why it matters
Earth's magnetic field is continuously changing.
Magnetic north wanders, and every few hundred thousand years the polarity gradually flips, so that a compass would point south instead of north.


To learn more about Earth's magnetic field, the three Swarm satellites were launched on 22 November.
Like 3D compasses, they are measuring the strength and direction of the magnetic field.

Saturday, February 8, 2014

Spider crabs vs. stingray


BBC Life - Creatures of the Deep
Huge stingray crashes a spider crab party

Friday, February 7, 2014

The motion of our oceans revealed: Hypnotic interactive globe reveals our planet’s powerful sea currents in real time


The detail is incredible.
A region that looks calm at first glance is seen as an active area of currents on closer inspection, using the mouse wheel to zoom in.

From DailyMail

  • Created by Tokyo-based Cameron Beccario, users can drag the globe to their desired location and click to zoom in
  • A region that looks calm at a first glance is seen as an active area of currents circling as the user moves closer in
  • It follows an interactive global wind map, also created by Mr Beccario (see GeoGarage blog). Studied together, they reveal just how unpredictable our planet’s weather system can be.
If you’ve ever wanted to sail through the world’s powerful ocean currents, then take a look at this.

Created by Tokyo-based Cameron Beccario, this interactive globe shows the ocean currents in real time as they swirl around continents.
Users can drag the globe to their desired location and click on the spot they want to find out an ocean current in all its grandeur.

Fascinatingly, the globe gives viewers an insight into the five major ocean gyres, the large systems of rotating ocean currents, particularly those involved with large wind movements.
The five - located in the Indian Ocean and in the north and south of the Pacific and the Atlantic - are clearly visible and their affects can be traced throughout the world.

This globe shows the ocean currents in real time as they swirl around continents

Pictured here is the ocean current system close to the UK.
The colours in this map denote speed, with red the fastest at over 1 metre per second and blue showing a static state
 
 Fascinatingly, the globe gives viewers an insight into the major ocean gyres, the large systems of rotating ocean currents, particularly those involved with large wind movements
 
The map relies on data compiled by NOAA's Global Forecast System to update its global wind patterns every three hours, and OSCAR Earth and Space Research to update its ocean surface current patterns every five days.
Details are thin on the ground on the sparsely-designed website, created by software engineer Mr Beccario, but it describes itself as a 'visualisation of global weather conditions forecast by supercomputers'.

It follows an interactive global wind map, also created by Mr Beccario.
Studied together, they reveal just how unpredictable our planet’s weather system can be.
Ocean currents transport huge amounts of heat around the world, making them one of the most important driving forces of climate.
Perhaps the most striking example is the Gulf Stream, which makes northwest Europe milder than other regions at the same latitude.

The ocean currents map follows an interactive global wind map (pictured), also created by Mr Beccario.
Studied together, they reveal just how unpredictable our planet's weather system can be

The currents are generated from the forces acting upon the water like the Earth's rotation, the wind, the temperature and salinity differences and the gravitation of the moon.
The colours in this map denote speed, with red the fastest at over 1 metre per second and blue showing a static state.

Links :

The data visualization in this excerpt represents a high point in the Scientific Visualization Studio's work in recent years to show "flows" -- ocean currents, winds, the movement of glaciers.
Using data from sophisticated NASA models, the studio's visualizers have figured out how to illustrate the velocities of these natural phenomena. 

Thursday, February 6, 2014

Here’s how the Internet’s arteries travel across the world's oceans in 2014

Interactive version of the 2014 submarine cable map.
TeleGeography’s Submarine Cable Map has been updated for 2014, 
providing an excellent representation of the infrastructure that makes global connectivity global.
The latest edition depicts 285 cable systems that are currently active or due to enter service by 2015.

From Gigaom

Great news for connectivity connoisseurs: the analyst firm TeleGeography just published this year’s edition of its world map, featuring all the submarine cable systems that comprise the arteries of the internet.

The map also shows the cables’ landing points, which is handy for those who take an interest in the current surveillance scandal.
Why is British intelligence so good at tapping cables?
Here’s why – so many of them pass through the U.K.:

Cable map UK

The 2014 edition includes 263 cables that are lit (in service), and 22 that should be lit by the end of 2015, so 285 cable systems in total.
Last year’s map showed 244 cables, and the year before that just 150, so the cable-laying boom of a few years back has definitely slowed down.

Unfortunately this year’s edition lacks a neat feature of Telegeography’s 2012 and 2013 maps, which was a breakdown of how much of the cable systems’ capacity is actually being used.
It also doesn’t have the 2013 edition’s Olde Worlde appeal.
On the plus side, it does offer a good breakdown of cable faults over recent years, cable-laying ships and maintenance zones, if that’s your thing.

One cable system that’s not on the map, probably because it will only go live in 2016, is the Asia Africa Europe-1 (AAE-1) cable that was detailed on Tuesday.
AAE-1 will run from South-East Asia to Africa and Europe via the Middle East, and yesterday the backing consortium announced membership including the likes of China Unicom, PCCW, Etisalat and Ooredoo.


Main projection

The map depicts routes of 263 in-service and 22 planned undersea cables.
Each country is colored according to how many international submarine cable system links are connected there.
Capital cities and the location and direction of 44 cable vessels (as of December 6, 2013) are also provided.

 

Cable landing sites

The map provides detailed information about cable landing stations in key regions including Hawaii,Southern Florida, New York, New Jersey, Cornwall, Singapore, Hong Kong, Tokyo, and Sydney.



Inset map

An inset map presents geographically accurate submarine cable paths, the locations of seven cable maintenance agreement zones, and subsea topographical features.




 

Cable installation

The map includes a diagram highlighting the various parts of a submarine cable system, including a submarine cable cross section.



Cable faults

Infographics provide data on cable faults and repairs, including:
  • Causes of cable faults, 2008-2011
  • Number of cable breaks by country, 2008-2012
  • Mean time to commence repair by country, 2008-2012


Seabed profiles

The map provides examples of trans-Atlantic and trans-Pacific cable route seabed profiles.



All these submarine telecommunication cables leading to the following map of the Internet :

Map of the Internet 1.0: explore this beautiful, hand-drawn map of the online world
(see The Independant)

Links :

Wednesday, February 5, 2014

New species of sea anemone discovered in Antarctica


During a routine test of an underwater robot, NSF scientists from University of Nebraska-Lincoln made a startling discovery...an entirely new species of sea anemone living inside the ice.

From NSF

National Science Foundation (NSF)-funded researchers from the University of Nebraska-Lincoln, while using a camera-equipped robot to survey the area under Antarctica's Ross Ice Shelf, unexpectedly discovered a new species of small sea anemones that were burrowed into the ice, their tentacles protruding into frigid water like flowers from a ceiling.
"The pictures blew my mind, it was really an amazing find," said Marymegan Daly, a specialist in sea anemones at Ohio State University, who studied the specimens retrieved by scientists and engineers with the NSF-funded Antarctic Geological Drilling (ANDRILL) Program's Coulman High project.

The team made the astonishing discovery of thousands upon thousands of the small anemones.

The new species, discovered in late December 2010, was publicly identified for the first time in an article published last month in PLOS ONE, an open-access, peer-reviewed journal published by the Public Library of Science.

Known localities of Edwardsiella andrillae, n. sp.
The site labeled A is at 77° 31.6’ S 171° 20.1’ E ; this corresponds to “Site 3” for the 2010-2011 SCINI dive series.

The site labeled B is at 77° 28.03’ S 171° 36.28’ E ; this corresponds to “Site 4 (CH-1)” for the for the 2010-2011 SCINI dive series (Rack et al., 2012).

Though other sea anemones have been found in Antarctica, the newly discovered species is the first reported to live in ice.
They also live upside down, hanging from the ice, compared to other sea anemones that live on or in the seafloor.

The white anemones have been named Edwardsiella andrillae, in honor of the ANDRILL Program.

Scott Borg, who heads the Antarctic Sciences Section in NSF's Division of Polar Programs, noted that the discovery indicates how much remains both unknown and unexplored by scientists, even after more than 50 years of active U.S. research on the Southernmost continent
"It is an absolutely astonishing discovery--and just how the sea anemones create and maintain burrows in the bottom of the ice shelf, while that surface is actively melting, remains an intriguing mystery," he said.
"This goes to show how much more we have to learn about the Antarctic and how life there has adapted."

NSF is responsible for managing all scientific research and logistics of the U. S. Antarctic Program on the Antarctic continent and in the Southern ocean.
The discovery was "total serendipity," said Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln.
"When we looked up at the bottom of the ice shelf, there they were."

Scientists had lowered the robot--a 4.5-foot cylinder equipped with two cameras, a side-mounted lateral camera and a forward-looking camera with a fish-eye lens--into a hole bored through the 270-meter-thick shelf of ice that extends over 600 miles northward from the grounding zone of the West Antarctic Ice Sheet into the Ross Sea.

Their research mission, funded by NSF with support from the New Zealand Foundation for Research, was to learn more about the ocean currents beneath the ice shelf to provide environmental data for modeling the behavior of the ANDRILL drill string (a length of pipe extending through the water column and into the sea floor through which drilling fluids are circulated and core samples are retrieved), Rack said.
They didn't expect to discover any organisms living in the ice, and surely not an entirely new species.

Rack, who is U.S. principal investigator for the environmental surveys that were conducted as part of the international ANDRILL Coulman High project, had left the site via helicopter just prior to the discovery.
He was listening by radio when he heard the report from the robot deployment team, composed of engineers Bob Zook, Paul Mahecek and Dustin Carroll, who began shouting as they saw the anemones, which appeared to glow in the camera's light.
"People were literally jumping up and down with excitement," Rack said. "They had found a whole new ecosystem that no one had ever seen before."
"What started out as an engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery," he said.

External anatomy and habitus of Edwardsiella andrillae n. sp.
A. Close up of specimens in situ. Image captured by SCINI. B.
“Field” of Edwardsiella andrillae n. sp. in situ.
Image captured by SCINI.
Red dots are 10 cm apart.

In addition to the anemones, the scientists saw fish who routinely swam upside down, the ice shelf serving as the floor of their submarine world, as well as polychaete worms, amphipods and a bizarre little creature they dubbed "the eggroll", a four-inch-long, one-inch-diameter, neutrally-buoyant cylinder, that seemed to swim using appendages at both ends of its body, which was observed bumping along the field of sea anemones under the ice and hanging on to them at times.

The anemones themselves measured less than an inch long in their contracted state--though they get three to four times longer in their relaxed state, Daly said.
Each features 20 to 24 tentacles, an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles.

After using hot water to stun the creatures, the team used an improvised suction device to retrieve the animals from their burrows.
They were then transported to McMurdo Station for preservation and further study.

Because the team wasn't hunting for biological discoveries, they were not equipped with the proper supplies to preserve the specimens for DNA/RNA analyses, Rack said.
The specimens were placed in ethanol at the drilling site and some were later preserved in formalin at McMurdo Station.

 Cnidae of Edwardsiella andrillae n. sp.
Scale at bottom, in µm, applies to all images.
See Table 1 for size ranges for each capsule type in each tissue.
A. Basitrich.
B. Spirocyst.
C. Spirocyst. Although this capsule is smaller and has a thinner tubule than the spirocyst in Figure 4A, spirocysts show continuous variation in capsule size and robustness.
D. Small basitrich.
E. Basitrich.
F. Small microbasic mastigophore. The small size of these cnidae precludes distinguishing them as b- or p- mastigophores.
G. Spirocyst.
H. Basitrich.
I. Microbasic p-mastigophore.
J. Small basitrich.
K. Basitrich.
L. Microbasic p-mastigophores.

Many mysteries remain about the creatures, the scientists report.
Though some sea anemones burrow into sand by using their tentacles or by expanding and deflating the base of their body, those strategies don't seem feasible for hard ice.
It is also unclear how they survive without freezing and how they reproduce.
There is no evidence of what they eat, although they likely feed on plankton in the water flowing beneath the ice shelf, Daly said.

Rack said a proposal is being prepared for further study of this unusual environment, using a robot capable of exploring deeper in the ocean and further from the access hole through the ice.
NASA is helping to finance the development of the new underwater robot because the Antarctic discoveries have implications for the possibility of life that may exist on Europa, the ice-covered moon of Jupiter. He said researchers hope to return to Antarctica as early as 2015 to continue studying the sea anemones and other organisms beneath the ice shelf.