Saturday, April 27, 2019

Augmented Reality (AR) in shipping

 MOL deploys augmented reality technology on tanker bridges :
The bridges of many of Japan’s Mitsui OSK Lines’ (MOL) tankers are set to get the fighter jet treatment with augmented reality (AR) technology deployed. 
The futuristic navigation system has been developed with compatriot Furuno and is now being installed on 21 VLCCs, after a successful pilot last year on one of the group’s new car carriers and another VLCC. 
The system displays information on other vessels sailing on a vessel’s planned route and surrounding sea areas and other ocean conditions, such as shallow waters. 
It integrates information from the automatic identification system (AIS) and radar with real-time video images from the bridge camera in collaboration with Furuno Electric’s Electric Chart Display and Information System (ECDIS) FMD3300 series. 
The system provides visual support to crewmembers during their watch-keeping and ship operations by using AR technology to superimposing real-time video imagery and voyage information. 
“Due to its deep draft, VLCC operations require special care when navigating on the waters such as the Straits of Singapore and Malacca, a heavily trafficked sea lane that has limited areas,” MOL noted in a release
MOL will install the system in its energy transport fleet including LNG carriers, as well as its dry bulk carriers. 
The company stated today that the technology will play a “key role” in realizing autonomous ships in the future.

Augmented Reality Ship exprimentation with Roll Royce 

Links :
  • YouTube : eAR is a navigation software that integrates hydrographic charts data to the surrounding space vision using augmented reality. EasyMarine offers the opportunity to evaluate, at your own discretion, all spaces in detail, in any visibility condition and with all relevant information.

Friday, April 26, 2019

Antarctica: thousands of emperor penguin chicks wiped out

When a petrel attackes them, emperor penguing chicks stand together against it. 

From BBC by Jonathan Amos

Thousands of emperor penguin chicks drowned when the sea-ice on which they were being raised was destroyed in severe weather.
The catastrophe occurred in 2016 in Antarctica's Weddell Sea.
Scientists say the colony at the edge of the Brunt Ice Shelf has collapsed with adult birds showing no sign of trying to re-establish the population.
And it would probably be pointless for them to try as a giant iceberg is about to disrupt the site.
The dramatic loss of the young emperor birds is reported by a team from the British Antarctic Survey (BAS).

Emperor penguins need a reliable and stable platform of sea-ice
 photo : Christopher Walton

Drs Peter Fretwell and Phil Trathan noticed the disappearance of the so-called Halley Bay colony in satellite pictures.
It is possible even from 800km up to spot the animals' excrement, or guano, on the white ice and then to estimate the likely size of any gathering.
But the Brunt population, which had sustained an average of 14,000 to 25,000 breeding pairs for several decades (5-9% of the global population), essentially disappeared overnight.

 The developing chasm in the Brunt Ice Shelf may have doomed the colony anyway

Emperors are the tallest and heaviest of the penguin species and need reliable patches of sea-ice on which to breed, and this icy platform must persist from April, when the birds arrive, until December, when their chicks fledge.

 2015: The guano stains at Halley colony are visible from space

If the sea-ice breaks up too early, the young birds will not have the right feathers to start swimming.
This appears to have been what happened in 2016.

Strong winds hollowed out the sea-ice that had stuck hard to the side of the thicker Brunt shelf in its creeks, and never properly reformed. Not in 2017, nor in 2018.
Dr Fretwell said: "The sea-ice that's formed since 2016 hasn't been as strong. Storm events that occur in October and November will now blow it out early. So there's been some sort of regime change. Sea-ice that was previously stable and reliable is now just untenable."
The BAS team believes many adults have either avoided breeding in these later years or moved to new breeding sites across the Weddell Sea.
A colony some 50km away, close to the Dawson-Lambton Glacier, has seen a big rise in its numbers.

  2018: The Dawson-Lambton colony has increased its numbers

Quite why the sea-ice platform on the edge of the Brunt shelf has failed to regenerate is unclear. There is no obvious climate signal to point to in this case; atmospheric and ocean observations in the vicinity of the Brunt reveal little in the way of change.
But the sensitivity of this colony to shifting sea-ice trends does illustrate, says the team, the impact that future warming in Antarctica could have on emperor penguins in particular.
Research suggests the species might lose anywhere between 50% and 70% of its global population by the end of this century, if sea-ice is reduced to the extent that computer models envisage.

  Emperors are the tallest and heaviest of the penguin species
photo : Christopher Walton

This would have consequences beyond just the emperors themselves, commented Dr Michelle LaRue, an ecologist at the University of Canterbury, New Zealand.
"They're an important part of the food web; they're what we call a mesopredator. They're both prey for animals like leopard seals but they also prey themselves on fish and krill species. So, they do play an important role in the ecosystem," she told BBC News.

Dr Trathan said: "What's interesting for me is not that colonies move or that we can have major breeding failures - we know that. It's that we are talking here about the deep embayment of the Weddell Sea, which is potentially one of the climate change refugia for those cold-adapted species like emperor penguins.
"And so if we see major disturbances in these refugia - where we haven't previously seen changes in 60 years - that's an important signal."
Whether the Halley Bay colony specifically really had a future is a moot point.

The Brunt Ice Shelf is being split apart by a developing crack.
This chasm will eventually calve an iceberg the size of Greater London into the Weddell Sea, and any sea-ice stuck to the berg's edge may break up in the process.
The colony could have been doomed regardless of what happened in 2016.
Drs Peter Fretwell and Phil Trathan report their investigation in the journal Antarctic Science.

Links :

Thursday, April 25, 2019

The risks to migrants of crossing the English Channel

source : MarineTraffic

From The Economist by G.D.

Immigration checks are almost non-existent, but turbulent waters bring other problems

Stand on Britain’s southern shore, looking towards France, and your gaze will settle upon the world’s busiest shipping lane.
Over 600 cargo ships pass through the English Channel each day.

 A maritime version of Guernica realized by Javcho Savov

Many are heading to and from London or Rotterdam, separated by what amounts to a motorway-style central reservation that they may not cross (see image).
Adding to the traffic are more than 60 daily cross-Channel ferry services, as well as fishermen and private recreation vessels that can number in the thousands on a summer weekend.
To date, only small numbers of migrants have tried to reach Britain this way, but their numbers are rising: 539 migrants attempted the journey last year, according to figures from the Home Office, but around 80% of these attempts were made in the last three months of 2018.

Is Brexit driving the surge in migrants crossing the English Channel by boat?
 photo : AFP

What are the risks and rewards of making the crossing?

The risks are clear: this is a testing crossing even for an experienced sailor with a seaworthy boat.
It is not just maritime collisions that skippers have to think about.
Tides in the Channel are among the biggest in the world.
The island of Jersey has a maximum tidal range of over 12m (39ft).
At low tide up to 3km of beach and rock can be exposed.
The channel goes from 240km at its widest point to 33km at its narrowest, which is why tidal races such as the Alderney Race, a strait just off the Cotentin Peninsula of France, or the waters just off Portland Bill near Weymouth are so notorious.
These can create treacherous seas even on the calmest of days.
Then there are sandbanks, shoals, isolated rocks and other dangers to negotiate—and that’s before the weather plays its unpredictable part.

Iranian migrants being picked up by the Gendarmerie Maritime in Calais.
Photograph: Gendarmerie Maritime

Yet for migrants and traffickers this particular route also has a definite upside.
Perhaps because of longstanding assumptions about the sea’s effectiveness as a barrier, there is little in the way of security controlling the movement of pleasure craft.
Many hundreds of ports along Britain’s south coast can be entered by small boats, which are greeted by little more than a poster (see image) suggesting that a phone call to the authorities or the national yachtline may be required to declare the immigrant status of certain sailors.
Official ports of entry such as Portsmouth or Southampton are for ferries and commercial traffic and a world away from an unmanned wooden jetty or marina berth where people come and go at all hours.

The traditional flag etiquette for those arriving from a foreign trip was to fly a yellow quarantine (Q) flag before getting the all-clear from officials who would check on travellers’ health and customs matters.
The flying of the flag is still a requirement for ships coming to Britain from outside the EU (owing to concerns about disease more than migrants), but small boats do not always adhere to the rule.
And a craft registered within the EU and wishing to enter another EU port need not show the Q flag at all, so there is no indication whether it has come from abroad or from just up the coast.
On many occasions your correspondent has enjoyed a breezy daytime crossing, a berth in a French port, steak frites on shore, and a jaunt back home the next day, with never a form filed or passport asked for.

 Britain will recall two overseas border patrol boats in response to a spike in migrants attempting to cross the English Channel in dinghies.

Britain’s Border Force has four cutters that are unlikely to patrol en masse in the Dover Strait.
They may not be enough.

Links :

Wednesday, April 24, 2019

NOAA encourages all mariners to use NOAA ENC® for latest updates and other advantages

The New Orleans Baton Rouge Steamship Pilots Association uses a portable pilot unit displaying NOAA ENC® data as it guides a tanker running upriver from New Orleans to Baton Rouge.


NOAA’s Office of Coast Survey maintains a suite of over 1,000 NOAA electronic navigational charts (ENC) and paper nautical charts, and like many other chart producing nations, maintains an ENC focused production process called “ENC-first.”
That is, ENCs are the “first” or primary nautical product, and new data is compiled onto ENCs before all other products.

NOAA ENC® data was originally created by digitizing paper nautical charts – starting in the early 1990s – but ENCs are now considered NOAA’s primary nautical chart product.
NOAA’s production process is now reversed.
That is, new source data and critical corrections are compiled into NOAA’s ENC production database first and the compiled portrayal of that data is subsequently applied to the corresponding paper charts and their associated digital raster products.
This sequential compilation process ensures the consistent equivalent portrayal of data between ENCs and paper nautical charts.

In this blog, when discussing aspects of paper charts and paper chart production, the same factors also apply to all corresponding digital raster chart products.
These digital images, identical to NOAA paper nautical charts, include the NOAA raster navigational chart (NOAA RNC®) – also known as BSB format, full-size and booklet charts released as PDF files, and RNC tile service data.

Synchronization of NOAA ENC and paper nautical charts

Because new chart source data is applied to ENCs first, there can be a delay of a month or more before the same information appears on paper nautical charts and their raster chart equivalents.
This is a characteristic of the standard production process.
This enables NOAA to provide the public with updated information as early as possible – in ENCs. Strict synchronization of ENC and raster products would require holding back the release of updated ENCs to enable the paper charts to catch up.

Releasing ENCs first is in the best interest of safe navigation.

Cartographer Julio Castillo reviews controlling depths in the Canaveral Barge Canal in Florida
 on ENC US5FL82M.

Data that could appear on ENCs before paper nautical charts

Coast Survey receives many types of data to compile on its nautical chart products.
Chief among these are hydrographic surveys used to update water depth values and the positions of rocks, wrecks, and other hazards; and topographic surveys used to update shorelines and some landmarks.
The application of these surveys usually constitutes a major update for ENCs and paper charts.
After compilation, this data is released to the public at the next weekly update of ENC products, which usually occurs on Thursdays.
This same data may not appear on some paper charts for up to a month or longer, and in some cases, it may not be published until the next new edition of the chart, which could be several months or even a few years away.

NOAA strives to keep both ENC and raster products up-to-date with Notice to Mariner corrections, but again, because NOAA does not hold back the release of this critical data, there can be a variation in the timing of Notice to Mariner based correction releases between products.

ENC data that is not available on paper nautical charts

Data that is only available on ENCs includes the minimum (also called controlling) depths of navigational channels maintained by the U.S Army Corps of Engineers.
NOAA is transitioning its paper nautical charts to show only the channel project design depths in many ports.
New minimum channel depths are provided as often as monthly for some channels.
Read more about this on the “NOAA announces change in channel depths on raster nautical chart products,” blog post.

Similar to the source diagrams on paper nautical charts, ENCs also provide a graphic representation of the extents of hydrographic surveys used to compile the depth data on the ENC.
However, unlike the diagrams on a paper chart, the quality of the surveys – indicated by a number of stars – may be toggled on and off over the ENC data itself.
This is easier than trying to match an area on a chart to the chart’s source diagram and then look up a quality category keyed to a letter shown on the diagram.

A new note will soon appear on all paper nautical charts

To reinforce the new nature of our nautical chart products in the ENC-first chart production environment, NOAA has started to place a note on all paper nautical charts that will encourage nautical chart users to take advantage of the benefits of using ENCs.

Other advantages of using ENCs

Low Cost Option – NOAA ENCs and ENC updates may be downloaded for free from the Coast Survey website.
They are also available from a number of value added resellers who offer services such as increased security through encryption and managed chart updates.
Generally, NOAA paper nautical charts each cost $20 or more.

Larger Scale Coverage – As part of a multi-year transition, many areas of ENC coverage will be offered at a larger scale.
Larger scale charts will offer more detail, including features such as high-density depth contours.
This more detailed data will only be available in the ENC format.
There are no plans to create new, larger scale paper charts.

Easier to Update – No hand corrections are needed on ENCs as is the case to update paper nautical charts.
Loading ENC revision files automatically apply all the latest ENC updates.
ENC updates are available weekly from NOAA and its value added resellers.

Less Clutter / Smarter Data – The database within each ENC enables users to turn the display of certain features and groups of text on and off on many navigational systems or chart plotters.
This can reduce clutter and make other important features easier to see that are more relevant for a particular activity in which a ship is engaged.
The minimum scale attribute that is encoded for many ENC features also enables systems to suppress the display of certain features when a chart is zoomed out to a point where a feature’s display would clutter the chart.
ENC data also has additional information that can be accessed by a mouse click (or query) on a chart display.
This includes information about the date and origin of the source data used to compile features on the ENC, any text associated with a feature, such as place names or light characteristics for buoys and other aids to navigation, can be turned off by the user, but quickly accessed by a query.

Added Level of Safety – Many navigational systems – including all the systems used by large commercial vessels – take advantage of the ENC’s database of depth areas, dangers to navigation, and regulated or restricted areas.
These systems use information in ENCs, as well as the ship’s draft input by the mariner, and information from the ship’s sensors, such as a GPS receiver, to plot the ships position, speed, and direction; the system can then also determine if the ship is heading in to unsafe waters.
Having this data available enables these systems to initiate visual and auditory alarms to alert the crew when a ship is moving into a dangerous condition, such as deviating from its planned course, entering an area shoaler than the ship’s draft, or entering other dangerous or restricted areas.

Always Oriented Correctly – ENCs have no inherent orientation.
That means no matter if the ENC display is set to display “north up,” “course up,” or some other orientation, the symbols and text on the digital chart display will always be displayed facing up for easy reading and interpretation.

NOAA Custom Chart – This capability, currently being prototyped by Coast Survey, will enable users to define the extent, scale, and paper size of their own customized paper chart, created from the latest ENC data and output as a PDF file.
Recreation boaters may print these files to use as a backup for their chart display systems or for small scale overview planning.

Links :

Bitcoin couple could face death penalty for ‘seasteading’ home off Thailand coast

The first small step to humanity’s future on the seas has been taken.
Are you ready to make the leap and live free on the sea?
In Episode 4, Chad and Nadia share what it’s like to live on the seastead and their hopes for the future.

From TheEpochTimes by

An American bitcoin investor and his Thai partner could face life in prison or even the death penalty for alleged violation of Thailand’s sovereignty by occupying a floating home off the country’s coast.

Chad Elwartowski and Supranee Thepdet (aka Nadia Summergirl) sought to be pioneers in the “seasteading” movement, which promotes living in international waters to be free of any nation’s laws.
But Thailand’s navy said Elwartowski and Thepdet posed a threat to the country’s national sovereignty, an offense punishable by life imprisonment or death.

The cabin was situated within Thailand’s exclusive economic zone (EEZ), but not its territorial sea.
Under the United Nations Convention on the Law of the Sea (pdf), to which Thailand is a party, an EEZ extends 200 nautical miles from a nation’s coastline.
Within it, a state has exclusive rights to natural resources such as fish and oil but does not have full sovereignty.
It does have the latter within its territorial waters, which extend out 12 nautical miles from the shore. 
Localization with the GeoGarage platform (Thaï nautical maps) 

 More detailed localization with the GeoGarage platform (NGA nautical maps)

Thai authorities on April 13 raided the couple’s floating home in the Andaman Sea, about 12 nautical miles from shore.

Thailand’s navy claims the couple endangered national sovereignty, an offense punishable by life imprisonment or death.
The couple was not at the home at the time of the raid on April 18, 2019. (Royal Thai Navy via AP)

Elwartowski and Thepdet were not at the home at the time of the raid and have gone into hiding.
In a Facebook post on Monday—since deleted—Elwartowski wrote, “Thailand wants us killed.”
“Hunting us down to our death is just plain stupid and highlights exactly the reason someone would be willing to go out in the middle of the ocean to get away from governments,” he wrote.
“We never had any ill intentions and I even state plainly several times that I would not want to be a citizen of any seastead nation that would have me.”

The couple wrote on their website that the floating home is anchored outside Thailand’s territorial waters, at least 12 nautical miles off the coast of Phuket.
“It’s designed to ignite an entire libertarian movement of freedom seekers gearing up to live in permanent dwellings at sea—outside of the jurisdiction of any government,” wrote Thepdet.

The claim is supported by an official statement released by Ocean Builders, the company who built the couple’s floating home, officially called XLII and billed as “the first seastead.”
“Our AIS beacon is still displaying our position 13 nautical miles from Thailand outside of Thailand’s territorial waters,” Ocean Builders wrote.
“It is claimed by the Thai navy through their media mouth pieces that the seastead is in a shipping lane,” Ocean Builders wrote.
“This makes it sound like there is heavy cargo traffic coming to Phuket. If anyone knows Phuket, they have one cargo port that gets maybe one or two cargo ships a week. They also admit that the seastead is in international waters, at least 12 nautical miles from land.”

 A Royal Thai navy ship drags a floating home, lived in by a U.S. man and his Thai partner, in the Andaman Sea, off Phuket Island in Thailand, on April 22, 2019.

But a Thai deputy naval commander insisted the project was a threat.
“This affects our national security and cannot be allowed,” Rear Adm. Wintharat Kotchaseni told Thai media on Tuesday, as cited by The Associated Press.
He said the floating house also posed a safety threat to navigation if it broke loose because the area is considered a shipping lane.

Thai police Col. Nikorn Somsuk told the South China Morning Post that the authorities were seeking clarification with the attorney general on how to proceed with the case since the outpost was technically in international waters.
“We have not met the couple yet. We have sent investigators to their home but they were not there,” he told The Post. “We don’t know what their thoughts are apart from the fact that it seems a bit extreme to want to be so isolated.”

He hinted the couple may not face the most serious punishment, telling the South China Morning Post, “As of now, there is no evidence that their actions pose a risk to Thai sovereignty.”

The couple has been charged with article 119 of the Thai Criminal Code, which prohibits any acts that cause a deterioration of Thailand’s independence.

Why seastead? Joe Quirk, co-author of the book "Seasteading, How Ocean Cities Will Change the World," has more than a couple of reasons.
Joe was one of dozens who attended the Seasteading Conference 2012 in San Francisco, which brought together dedicated adventure seekers and entrepreneurs looking to transform the ocean into the next frontier for humanity.
Every great change throughout history has begun with a group of individuals who dreamt up a desire, and then acted to make their vision a reality.
The number of reasons behind the desire to seastead are as numerous as the number of people in our community.
Why are you seasteading?

‘Excited About the Project’

“We were hoping to bring tourism to Phuket with an underwater restaurant, floating hotels, and medical research, tech jobs, etc. We had 3 wealthy entrepreneurs in the past week tell us they were coming to live in Phuket because they were excited about the project,” Elwartowski wrote on Facebook.

A promotional video from March showed the couple toasting champagne on the floating home.
“Ocean Builders is selling this ocean-front property at a fraction of the cost of any other place you would get oceanfront property,” Elwartowski says in the video, plugging the project as “something completely brand new.”

He added the home was the first of an additional 20 homes planned.
“May the seastead be a beacon to freedom lovers everywhere,” Elwartowski said in the video.

Meanwhile, Ocean Builders announced that due to the raid, the sale of its seastead homes “is to be postponed until we can get everything straightened out and figure out the best path forward for everyone.”

According to the company’s website, “seasteading is the concept of creating permanent dwellings at sea, called seasteads, outside the territory claimed by any government. The term is a combination of the words sea and homesteading.”

Links :

Tuesday, April 23, 2019

Norway (NHS) layer update in the GeoGarage platform

130 nautical raster chazrts updated & 2 new insets added

These ocean floats can hear earthquakes, revealing mysterious structures deep inside Earth

A MERMAID undergoes testing off Japan's coast in 2018
photo : Alex Burky / Princeton University

From ScienceMag by Erik Stokstad

A versatile, low-cost way to study Earth's interior from sea has yielded its first images and is scaling up.
By deploying hydrophones inside neutrally buoyant floats that drift through the deep ocean, seismologists are detecting earthquakes that occur below the sea floor and using the signals to peer inside Earth in places where data have been lacking.

In February, researchers reported that nine of these floats near Ecuador's Galápagos Islands had helped trace a mantle plume—a column of hot rock rising from deep below the islands.
Now, 18 floats searching for plumes under Tahiti have also recorded earthquakes, the team reported last week at the European Geosciences Union (EGU) meeting here.
"It seems they've made a lot of progress," says Barbara Romanowicz, a geophysicist at the University of California, Berkeley.

A MERMAID recently launched near Tahiti is sending messages to the satellite before diving a mile underwater to begin monitoring for earthquake signals.
Photo by Frederik Simons, Department of Geosciences

The South Pacific fleet will grow this summer, says Frederik Simons, a seismologist at Princeton University who helped develop the floats, called MERMAIDs (mobile earthquake recorders in marine areas by independent divers).
He envisions a global flotilla of thousands of these wandering devices, which could also be used to detect the sound of rain or whales, or outfitted with other environmental or biological sensors.
"The goal is to instrument all the oceans."

Drifting a mile below the surface, MERMAIDs cover a large area. The red circles show where a MERMAID picked up a seismic signal.
Image courtesy of the researchers

For decades, geologists have placed seismometers on land to study how powerful, faraway earthquakes pass through Earth.
Deep structures of different density, such as the cold slabs of ocean crust that sink into the mantle along subduction zones, can speed up or slow down seismic waves.
By combining seismic information detected in various locations, researchers can map those structures, much like 3D x-ray scans of the human body.
Upwelling plumes and other giant structures under the oceans are more mysterious, however.
The reason is simple: There are far fewer seismometers on the ocean floor.

Such instruments are expensive because they must be deployed and retrieved by research vessels.
And sometimes they fail to surface after yearlong campaigns.
More recently, scientists have begun to use fiber optic communication cables on the sea floor to detect quakes, but the approach is in its infancy.

MERMAIDs are a cheap alternative.
They drift at a depth of about 1500 meters, which minimizes background noise and lessens the energy needed for periodic ascents to transmit fresh data.
Whenever a MERMAID's hydrophone picks up a strong sound pulse, its computer evaluates whether that pressure wave likely originated from seafloor shaking.
If so, the MERMAID surfaces within a few hours and sends the seismogram via satellite.

The nine floats released near the Galápagos in 2014 gathered 719 seismograms in 2 years before their batteries ran out.
Background noise, such as wind and rain at the ocean surface, drowned out some of the seismograms.
But 80% were helpful in imaging a mantle plume some 300 kilometers wide and 1900 kilometers deep, the team described in February in Scientific Reports.
The widely dispersed MERMAIDs sharpened the picture, compared with studies done with seismometers on the islands and in South America.
"The paper demonstrates the potential of the methodology, but I think they need to figure out how to beat down the noise a little more," Romanowicz says.

This animation shows every recorded earthquake in sequence as they occurred from January 1, 1901, through December 31, 2000, at a rate of 1 year per second.
The earthquake hypocenters first appear as flashes then remain as colored circles before shrinking with time so as not to obscure subsequent earthquakes.
The size of the circle represents the earthquake magnitude while the color represents its depth within the earth.
At the end of the animation it will first show all quakes in this 100-year period.
Next, it will show only those earthquakes greater than magnitude 6.5, the smallest earthquake size known to make a tsunami.
It will then show only those earthquakes with magnitudes of 8.0 or larger, the “great” earthquakes most likely to pose a tsunami threat when they occur under the ocean or near a coastline and when they are shallow within the earth (less than 100 km or 60 mi. deep).
The animation concludes by showing the plate boundary faults responsible for the majority of all of these earthquakes.
The era of modern earthquake seismology—the scientific study of earthquakes—began in the 20th Century with the invention of the seismometer and its deployment in instrument networks to record and measure earthquakes as they occur.
Therefore, when the animation begins only the largest earthquakes appear as they were the only ones that could be detected at great distances with the few available instruments available at the time.
But as time progresses, more and more seismometers were deployed and smaller and smaller earthquakes could be recorded.
For example, note how in the 1930’s many small earthquakes suddenly seem to appear in California, but this illusion results from the installation of more and more instruments in that region.
Likewise, there appears to be a jump in the number of earthquakes globally in the 1970’s when seismology took another leap forward with advances in telecommunications and signal processing with digital computers, a trend that continues today.
20th Century seismology revealed the global geographic distribution of earthquakes and helped to solidify the Theory of Plate Tectonics.
Notice how earthquake epicenters do not occur randomly in space but form patterns over the earth’s surface, revealing the boundaries between tectonic plates as shown toward the end of this animation.
This time period also includes some remarkable events, including those that generated devastating tsunamis:
8.8 — Ecuador — 31January 1906 8.4 — Kamchatka, Russia — 3 February 1923 8.4 — Sanriku, Japan — 2 March 1933 8.6 — Unimak Island, Aleutian Islands — 1 April 1946 9.0 — Kamchatka, Russia — 4 November 1952 8.6 — Andreanof Islands, Aleutian Islands — 9 March 1957 9.5 — Valdivia, Chile — 22 May 1960 9.2 — Prince William Sound, Alaska — 28 March 1964 8.7 — Rat Islands, Aleutian Islands — 4 February 1965
These earthquakes represent some of the largest ever recorded.
Note how they all occur at a particular type of plate boundary, subduction zones where tectonic plates collide, so these are the regions where we expect future devastating tsunamis to be generated.
This animated map created from the NOAA, NWS, and PTWC shows every recorded earthquake in chronological order from January 1, 2001 to December 31, 2015.
The size of the circle shows the magnitude of the earthquakes in relation to each other.
The color represents the earthquake depth.

Since that campaign, the MERMAID design was reworked by research engineer Yann Hello of Geoazur, a geoscience lab in Sophia Antipolis, France.
He made them spherical and stronger, and tripled battery life.
The floats now cost about $40,000, plus about $50 per month to transmit data.
"The MERMAIDs are filling a need for a fairly inexpensive, flexible device" to monitor the oceans, says Martin Mai, a geophysicist at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia.

Between June and September of 2018, 18 of these new MERMAIDs were scattered around Tahiti to explore the Pacific Superswell, an expanse of oddly elevated ocean crust, likely inflated by plumes.
The plan is to illuminate this plumbing and find out whether multiple plumes stem from a single deep source.
"It's a pretty natural target," says Catherine Rychert, a seismologist at the University of Southampton in the United Kingdom.
"You'd need a lot of ocean bottom seismometers, a lot of ships, so having floats out there makes sense."

So far, the MERMAIDs have identified 258 earthquakes, Joel Simon, a graduate student at Princeton, told the EGU meeting.
About 90% of those have also been detected by other seismometers around the world—an indication that the hydrophones are detecting informative earthquakes.
Simon has also identified some shear waves, or S-waves, which arrive after the initial pressure waves of a quake and can provide clues to the mantle's composition and temperature.
"We never set out to get S-waves," he said.
"This is incredible." S-waves can't travel through water, so they are converted to pressure waves at the sea floor, which saps their energy and makes them hard to identify.

In August, 28 more MERMAIDS will join the South Pacific fleet, two dozen of them bought by the Southern University of Science and Technology in Shenzhen, China.
Heiner Igel, a geophysicist at Ludwig Maximilian University in Munich, Germany, cheers the expansion.
"I would say drop them all over the oceans," he says.

Links :

Monday, April 22, 2019

Sous l'eau

Sous l'eau from Petole Films by Olivier Sautet
is visual poem filmed all around the underwater world.
Location : Hawaii, Madagascar, France, Mauritius, Tahiti.
Music : Bach, Busoni - Chaconne D minor

Sunday, April 21, 2019

How Leonardo da Vinci made a “satellite” map in 1502

It was accurate — and incredibly imaginative.
How do you create a “satellite” map in 1502?
As the video above shows, it takes a lot of technical expertise and imagination.
Fortunately, that was Leonardo da Vinci’s expertise.
When Leonardo was installed at Imola, Italy, as politician Cesare Borgia’s military engineer, he was charged with helping Borgia become more aware of the town’s layout.
To do it, he made a groundbreaking map that combined cutting-edge surveying techniques with his artistic imagination.
The resulting “ichnographic” map was a step forward for cartography, transforming it from a partly imaginative exercise to an informational asset.
Check out the video above to see how he did it.
-From Vox by Phil Edwards-

It was a feat of technological and symbolic imagination.
And it was pretty accurate, too.
Leonardo da Vinci’s known for his art and inventions — but also his groundbreaking maps, like this one of Imola, Italy.

Drafting 1502’s equivalent to a “satellite” map was a massive undertaking, and Leonardo managed to pull it off.
His early map helped Italian politcian Cesare Borgia construct an idea of the town of Imola that was far more accurate than most contemporary maps.
Through the use of careful measurements of angles and pacing out distances using a primitive odometer, Leonardo managed to create a map that was very close to accurate.
This map — an “ichnographic” map — was a step forward in portraying how maps could work to represent geography.
Though it’s marked with some inaccuracies, it’s stunningly precise for the time and pushed forward the art of mapmaking.
Leonardo’s Imola remains, even today, a remarkably useful guide to the city.

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