115 nautical raster charts added + 1 new inset added
see GeoGarage news
Saturday, August 11, 2018
Friday, August 10, 2018
The unpleasant reason men navigate better than women
Sea Hero Quest Game - The first scientific results
From BBC by
Men are better at navigating than women, according to a massive study, but there's not much for men to be proud about.
Scientists at University College London say the difference has more to do with discrimination and unequal opportunities than any innate ability.
The findings come from research into a test for dementia.
But it has also given an unprecedented insight into people's navigational ability all around the world.
The experiment is actually a computer game, Sea Hero Quest, that has had more than four million players.
It's a nautical adventure to save an old sailor's lost memories and with a touch of a smartphone screen, you chart a course round desert islands and icy oceans.
Introducing Sea Hero Quest, a mobile game created to change the future of dementia research.
The game anonymously records the player's sense of direction and navigational ability.
One clear picture, published in the journal Current Biology, was that men were better at navigating than women.
But why?
Prof Hugo Spiers thinks he has found the answer by looking at data from the World Economic Forum's Gender Gap Index - which studies equality in areas from education to health and jobs to politics.
He told the BBC: "We don't think the effects we see are innate.
"So countries where there is high equality between men and women, the difference between men and women is very small on our spatial navigation test.
"But when there's high inequality the difference between men and women is much bigger. And that suggests the culture people are living in has an effect on their cognitive abilities."
Sea Hero Quest has produced a raft of other findings.
- Denmark, Finland and Norway have the world's best navigational skills - possibly down to their "Viking blood"
- Sense of direction is in constant decline after you emerge from your teenage years
- People in wealthier countries also tend to be the best navigators
The popularity of the game has turned it into the world's biggest dementia research experiment.
Being lost or disoriented is one of the first signs of the disease.
The next step in the research is to see if catching sudden declines in navigational ability could be used to test for dementia.
Tim Parry, the director of Alzheimer's Research UK, said: "The data from Sea Hero Quest is providing an unparalleled benchmark for how human navigation varies and changes across age, location and other factors.
"This really is only the beginning of what we might learn about navigation from this powerful analysis."
This project was funded by Deutsche Telekom and the game was designed by Glitchers.
Links :
- The Telegraph : Do men have a better sense of direction? Depends where you live, scientists say
- Phys : Nordic nations, North Americans and Antipodeans rank top in navigation skills
- Medical Press : Mobile game designed to help better understand dementia on a massive scale
- GeoGarage blog : About the effect of GPS technology on human sense ... / Polynesian navigators revive a skill that was nearly ...
Thursday, August 9, 2018
The Bermuda Triangle: A breeding ground for rogue waves or a pit of human mistakes?
Also sinisterly known as the Devil's Triangle, the Bermuda Triangle consists of a region in the western part of the North Atlantic Ocean, and is defined by points in Bermuda, Florida and Puerto Rico.
It stretches across less than a thousand miles on any one side.
…and then they just disappeared.
The Bermuda Triangle, a mysterious stretch of ocean between Bermuda, Puerto Rico and the tip of Florida, has allegedly, throughout the years, swallowed a horde of unsuspecting ships, planes and people.
Charles Berlitz's 1974 book kicked off a craze lasting into the 1980's
Sadly our planet’s mysteries have largely been explained
thanks to the proliferation of TV channels with midweek schedules to fill.
Many tales have been told about the vanishings.
Aliens captured the humans for research.
Some geomagnetic storm confused the pilots' navigational systems.
The lost continent of Atlantis sucked the vessels into its grasp with a mysterious, unidentified force.
Better yet, strong vortexes slurped the victims straight into another dimension.
But scientists throughout the years have pointed out that there are plausible explanations for the vanishings, and that the risks of traveling through the Bermuda Triangle are no different than other spots in the ocean.
The SS Marine Sulphur Queen, a converted T2 tanker ship carrying molten sulfur (sulphur is the British spelling of sulfur) and 39 crew members, disappeared near the southern coast of Florida.
It was last heard from on Feb. 4, 1963, when it sent a routine radio message.
When it failed to make further communication, search crews were dispatched to locate it.
After more than two weeks of looking, the rescue team only found a few shards of debris and life preservers, shown above.
It's a bit unsettling that the Sulphur Queen vanished into "the Devil's Triangle," since folklore says that the king of the underworld reeks of sulfur — and what's that creepy shadow in the photo's background, anyway?
New life has been breathed into one such theory: that the vessels could have easily been overcome by giant and unexpected rogue waves.
This hypothesis isn't new, but a group of U.K. scientists recently discussed the evidence for freak waves and other theories (including the role of human error) in a three-episode documentary series "The Bermuda Triangle Enigma," produced by the BBC for Channel 5.
This photo shows the U.S.S. Cyclops (AC-4), a massive collier ship that was lost at sea in 1918.
After leaving Barbados for Baltimore, Md., on March 4, the vessel vanished without a trace, taking 306 crew members and passengers with it.
It remains the single largest loss of life in U.S. Naval history that was not the result of combat.
"There is no doubt this area is prone to rogue waves," Simon Boxall, an oceanographer at the University of Southampton and one of the scientists on the team, told Live Science.
They are possible "anywhere you get multiple storms coming together."
The USS Nereus (AC-10) was one of four Proteus-class colliers built for the U.S. Navy during World War I. The craft was named after the mythological Greek sea god Nereus, protector of sailors.
The USS Nereus was lost at sea sometime after Dec. 10, 1941, as it made its way to Portland, Maine, from St. Thomas in the Virgin Islands.
It disappeared with a crew of 61 along the same route as its sister-ship, the USS Proteus, had vanished from the previous month.
The USS Proteus (AC-9) was a Navy collier that had been converted into a merchant ship.
It was never heard from again after Nov. 23, 1941, when it left port from St. Thomas in the Virgin Islands, bound for an East Coast port in the United States.
The approximately 540-foot-long (165 meters) ship was carrying 58 men and a cargo of bauxite ore to be made into aluminum.
Two of Proteus's three sister-ships, the Cyclops and Nereus, also vanished without a trace in the Bermuda Triangle.
Rogue waves are steep and tall, like "walls of water," and they often hit unexpectedly, according to the National Oceanic and Atmospheric Administration.
The tip of South Africa, for example, is very prone to them, where waves from storms in the South Atlantic Ocean, the Indian Ocean and the Southern Ocean all come together at once, Boxall said.
Indeed, there were similar disappearances of big container vessels and tankers off the tip of South Africa throughout the years, he said.
This also holds true for the Bermuda Triangle, where storms can come from all directions, like Mexico, the equator and farther east in the Atlantic.
If each wave can reach over 30 feet (10 meters) tall, occasionally they can coincide at the right moment and create a rogue, or "freak," wave that can be over 100 feet (30 m) high.
Engineers at the University of Southampton in England built some ship models, including one of the USS Cyclops, a vessel that vanished in the Bermuda Triangle in 1918 with over 300 people on board.
They simulated rogue waves in a wave tank and found that, indeed, ships can sink quickly if hit by them.
The bigger the ship, the bigger the difficulty staying afloat, they found.
Small ships can get swamped by them, but sometimes they can ride the wave if they hit it bow-on, Boxall said.
But big ships — designed to be supported in the front by the top of one wave and in the back by the top of another — snap in two.
Gas bubbles, magnetic anomalies…humans being humans?
People often talk about weird magnetic anomalies over the Bermuda Triangle, Boxall said.
"There aren't any," he said.
There are magnetic anomalies in the world that have to do with the Earth's mantle moving beneath the crust, but the nearest one is about 1,000 miles [1,600 km] south, off the coast of Brazil — a long way away from the Bermuda Triangle, he said.
Another theory has to do with pockets of explosive methane gas that could, due to some disturbance, float up toward the water's surface and cause the water to be less dense than the ship, leading the ship to sink.
However, no experiment to date has been able to prove that this is possible, Boxall said.
"Theoretically, it could be happening, but there are lots of places in the world where this can happen," not just in the Bermuda Triangle, Boxall said.
Instead, he thinks the most common cause for the mysterious vanishings is human error.
The Bermuda Triangle's eerie reputation began on Dec. 5, 1945, when flight 19, a squadron of five U.S. Navy torpedo bombers, vanished into thin air during a routine training exercise.
The planes were
fully equipped and had been thoroughly checked before they departed from
the Naval Air Station Fort Lauderdale in Florida.
What
made the disappearance even more mysterious is that it occurred during
peacetime, making it less likely that they were shot down.
This photo shows a U.S. Navy TBF Grumman Avenger flight, similar to the Flight 19 planes.
Before
losing radio contact off the coast of southern Florida, Flight 19's
flight leader was reportedly heard saying: "Everything looks strange,
even the ocean," and "We are entering white water, nothing seems right."
The
aircrafts and 14 crew members were never found, despite a lengthy
investigation by the government. In fact, a search-and-rescue aircraft
with 13 men onboard was dispatched to locate the missing planes, but
that aircraft and its passengers also inexplicably disappeared.
And thus, the Bermuda Triangle's spooky reputation was solidified.
The famous disappearance of Flight 19 — five U.S. Navy aircraft that vanished during a training mission in 1945 — that led one journalist in 1964 to give the area its current name, probably occurred because the crew got lost and ran out of fuel, Boxall said.
About a third of all registered and privately owned ocean craft in the U.S. are in the states and islands of the Bermuda Triangle area, he said.
And according to the most recent 2016 figures from the Coast Guard, 82 percent of incidents in this area that year involved people who had no formal training or experience of being at sea, he added.
"So, you take a third of the entire boating population of the U.S., you dump them in the Bermuda Triangle," and what you get is mysterious vanishings, Boxall said.
You don't need any licensing or specific equipment like radios or navigation maps to take a boat to sea, he added.
"A number of times, working at sea, we've come across people who are navigating using a road map, who are relying on their mobile phones as their means of communication, discovering … you get 30 miles offshore [and] you lose the signal," Boxall said.
Retrieving sunken planes and ships from the Bermuda Triangle is especially difficult because it is home to the Puerto Rico Trench, which reaches depths of about 30,100 feet (9,200 meters) and is the deepest part of the Atlantic Ocean.
Crafts that sink to such low points are seldom seen again.
This underwater photo shows an unidentified Caribbean shipwreck discovered by NOAA oceanography researchers on April 1, 2011.
In addition, "environmental considerations could explain many, if not most, of the disappearances," NOAA wrote on its website.
"The ocean has always been a mysterious place to humans, and when foul weather or poor navigation is involved, it can be a very deadly place."
NOAA also says the area could be prone to accidents because of the Gulf Stream, a strong and fast ocean current that can cause "rapid, sometimes violent, changes in weather," and shallow waters around the Caribbean islands that can prove fatal for ships.
"You can extend the Bermuda Triangle to ever bigger areas…what you'll find is that the Bermuda Triangle covers the entire globe," Boxall said.
"Rogue waves can hit lots of different places, methane bubbles can hit lots of different places, and wherever you get a high concentration of amateurs without any experience you're going to get a high concentration of mysterious disappearances."
But, you know, maybe it is aliens capturing unsuspecting humans using vortexes that lead straight into their laboratories that they've set up in the lost city of Atlantis.
Links :
- LiveSciences : Is the Bermuda Triangle Really Dangerous? / Bermuda Triangle: Where Facts Disappear / No, 'Honeycomb' Clouds Don't Explain Bermuda Triangle Mystery
- History : Bermuda Triangle Mystery: What Happened to the USS Cyclops?
- GeoGarage blog : Mystery of the Bermuda Triangle solved? / Mysterious waters: from the Bermuda Triangle to ... / The Bermuda triangle of space: the high-energy ...
Wednesday, August 8, 2018
Antarctic seas host a surprising mix of lifeforms – and now we can map them
In contrast to common perceptions, Antarctic seafloor communities are highly diverse.
This image shows a deep East Antarctic reef with plenty of corals, sponges and brittlestars.
Can you spot the octopus?
Australian Antarctic Division
From The Conversation by Jan Jansen
What sort of life do you associate with Antarctica?
Penguins? Seals? Whales?
Actually, life in Antarctic waters is much broader than this, and surprisingly diverse.
Hidden under the cover of sea-ice for most of the year, and living in cold water near the seafloor, are thousands of unique and colourful species.
An underwater robot has captured a rare glimpse beneath the Antarctic sea ice, revealing a thriving, colourful world filled with coconut-shaped sponges, dandelion-like worms, pink encrusting algae and spidery starfish.
The footage was recorded on a camera attached to a Remotely Operated Vehicle (ROV) deployed by Australian Antarctic Division scientists under the sea ice at O’Brien Bay, near Casey research station in East Antarctica.
Our research has generated new techniques to map where these species live, and predict how this might change in the future.
Biodiversity is nature’s most valuable resource, and mapping how it is distributed is a crucial step in conserving life and ecosystems in Antarctica.
Casey lies on the northern side of the Bailey Peninsula overlooking Vincennes Bay on the Budd Coast of Wilkes Land in the Australian Antarctic Territory, a territory claimed by Australia
NGA chart in the GeoGarage platform
The Casey Station, commonly called Casey, is one of three permanent bases and research outposts in Antarctica managed by the Australian Antarctic Division (AAD).
AHS chart in the GeoGarage platform
Surprises on the seafloor
The ocean surrounding the Antarctic continent is an unusual place.
Here, water temperatures reach below freezing-point, and the ocean is covered in ice for most of the year.
While commonly known for its massive icebergs and iconic penguins, Antarctica’s best-kept secret lies on the seafloor far below the ocean surface.
In this remote and isolated environment, a unique and diverse community of animals has evolved, half of which aren’t found anywhere else on the planet.
These solitary sea squirts stand up to half a metre tall at 220m depth in the dark, cold waters of East-Antarctica.
Images such as this one were taken with cameras towed behind the Australian Icebreaker Aurora Australis.
Australian Antarctic Division
Colourful corals and sponges cover the seafloor, where rocks provide hard substrate for attachment.
These creatures filter the water for microscopic algae that sink from the ocean surface during the highly productive summer season between December and March.
In turn, these habitat-forming animals provide the structure for all sorts of mobile animals, such as featherstars, seastars, crustaceans, sea spiders and giant isopods (marine equivalents of “slaters” or “woodlice”).
The Antarctic seafloor is also home to a unique group of fish that have evolved proteins to stop their blood from freezing.
Most Antarctic fish have evolved ‘anti-freeze blood’ allowing them to survive in water temperature below zero degrees C.Australian Antarctic Division
Mapping biodiversity is hard
Biodiversity is a term that describes the variety of all life forms on Earth.
The unprecedented rate of biodiversity loss is one of the biggest challenges of our time.
And despite its remoteness, Antarctica’s biodiversity is not protected from human impact through climate change, pollution and fisheries.
Although scientists have broadly known about Antarctica’s unique marine biodiversity for some time, we still lack knowledge of where each species lives and where important hotspots of biodiversity are located.
This is an issue because it hinders us from understanding how the ecosystem functions – and makes it hard to assess potential threats.
Why don’t we know more about the distribution of Antarctic marine species?
Primarily, because sampling at the seafloor a few thousand metres below the surface is difficult and expensive, and the Antarctic continental shelf is vast and remote.
It usually takes the Australian Icebreaker Aurora Australis ten days to reach the icy continent.
A selection of the diverse and colourful species found on the Antarctic seafloor.
Huw Griffiths/British Antarctic Survey
To make the most of the sparse and patchy biological data that we do have, in our research we take advantage of the fact that species usually have a set of preferred environmental conditions.
We use the species’ relationship with their environment to build statistical models that predict where species are most likely to occur.
This allows us to map their distribution in places where we have no biological samples and only environmental data.
Critically, until now important environmental factors that influence the distribution of seafloor species have been missing.
Using predictions to make a map
In a recent study, we were able to predictively map how much food from the ocean-surface was available for consumption by corals, sponges and other suspension feeders at the seafloor.
The science behind linking food-particles from the ocean surface to the biodiversity of Antarctic seafloor fauna.
Satellites (1) can detect the amount of algae at the ocean-surface.
Algae-production is particularly high in ice-free areas (2) compared to under the sea-ice (3).
Algae sink from the surface (4) and reach the seafloor.
Where ocean-currents are high (5), many corals feed from the suspended particles.
In areas with slow currents (6), particles settle onto the seafloor and feed deposit-feeding animals such as seacucumbers.
Jansen et al. (2018), Nature Ecology & Evolution 2, 71-80.
Although biological samples are still scarce, this allowed us to map the distribution of seafloor biodiversity in a region in East Antarctica with high accuracy.
Further, estimates of how and where the supply of food increased after the tip of a massive glacier broke off and changed ocean conditions in the region allowed us to predict where abundances of habitat forming fauna such as corals and sponges will increase in the future.
Antarctica is one of the few regions where the total biomass of seafloor animals is likely to increase in the future.
Retreating ice-shelves increase the amount of suitable habitat available and allow more food to reach the seafloor.
Colourful and diverse communities are also found living in shallow waters.
Australian Antarctic Division
For the first time in history, we now have the information, computational power and research capacity to map the distribution of life on the entire continental shelf around Antarctica, identify previously unknown hotspots of biodiversity, and assess how the unique biodiversity of the Antarctic will change into the future.
Links :
Subscribe to:
Posts (Atom)