Saturday, March 26, 2016

Image of the week : San Francisco HR oblique view


from Mapbox
DigitalGlobe’s WorldView-3 satellite collected an astonishing view of San Francisco
We don’t often see pictures like this one.
The problem is haze: as a camera in space looks toward the horizon, it sees more water vapor, smog, and other stuff in the atmosphere that obscures the Earth.
But our friends at DigitalGlobe built WorldView-3 with a sensor suite called CAVIS, which lets it quantify and subtract haze – making atmospheric effects virtually invisible.
Only WorldView-3 can see so clearly at this angle.
The satellite is about 17° above the horizon from San Francisco, and it is looking about 60° away from the point directly under it.
At first I thought there was a typo, because 17° off horizontal should be 73° off vertical, not 61°.
But while sketching it out, I realized I was assuming the ground is flat.
WorldView-3 is way out over the Pacific – more than 1300 km or 800 miles to the west, and over that distance the Earth curves by about 12°!
Pan and zoom to see landmarks and details
 

SF with the GeoGarage platform

Friday, March 25, 2016

Historic UN talks could save the high seas

No-man’s-land. B1mbo, CC BY-SA

From The Conversation by Glen Wright and Julien Rochette

You wouldn’t know it from land, but 45% of the surface of the globe lies outside the control of any government. The high seas (and seabed) are designated as “Areas Beyond National Jurisdiction” by the UN, with little regulation and few environmental safeguards.
Now, after a decade of discussions, a new treaty will be negotiated to ensure the conservation and sustainable use of the biodiversity in these areas.
The United Nations Convention on the Law of the Sea (UNCLOS), adopted in 1982, already provides a “Constitution for the Ocean”, but it doesn’t say much about the high seas or the seabed that lies beyond our borders.
Indeed, we used to believe that these areas were not worth exploiting or protecting, but scientific and technological advancements are opening up a world of possibilities.

In recent decades, cargo shipping has grown rapidly and industrial fishing has moved into ever deeper and more distant waters.
At the same time, a range of novel activities are under development.
Contracts have been signed with the International Seabed Authority to mine valuable minerals from the seabed, and scientists and entrepreneurs are dreaming up new ways to use the ocean to mitigate climate change through “geoengineering”.
One such idea is to “fertilise” the ocean with iron, stimulating algal blooms that can lock away carbon.
We have also found a wealth of potential uses for the unusual genes contained in unique deep sea organisms.
“Marine genetic resources” taken from these organisms are now turning up in everything from anti-cancer drugs to high-end skin creams. The search to find such genes, known as “bioprospecting”, has begun in earnest, with the US, Germany, and Japan, leading the charge.

All this activity puts further pressure on already stressed and fragile marine ecosystems, and will only be exacerbated by climate change and ocean acidification.
This is a problem. Though we are not always aware of the vast ocean expanse beyond the horizon, the high seas provide us with a range of invaluable resources, not least seafood, clean air, and the global sea routes that deliver goods from across the globe to our doorstep.
The high seas contain unique habitats - such as huge underwater mountains and vents that spew boiling water into the icy depths - and we are constantly discovering new flora and fauna making their homes in these extreme environments.
At the same time, high seas ecosystems are highly interconnected with the seas and coasts that do happen to fall within national jurisdiction, with species constantly criss-crossing the arbitrary lines we have drawn on the map. If we fail to to properly manage our global ocean, we have a lot to lose.

Tangled net

Unfortunately the global regulatory framework for these areas is a hodgepodge of different legal instruments and organisations that mostly do not work well together.
Even when they do, huge gaps remain.
There is currently no way to create internationally recognised marine protected areas (MPAs) on the high seas, while the exploitation of marine genetic resources has been a thorny issue because their status under international law is unclear.
There are no global rules requiring the assessment of the environmental impacts of a range of activities, including bioprospecting.

Despite a consensus decision to press on with negotiations, states haven’t always seen eye to eye.
In particular, there has been intense ideological debate about the status of marine genetic resources: developing countries are concerned that only the wealthiest countries can afford to exploit this common resource, while many developed countries don’t want their potentially profitable activities to be subject to regulation.
States agree on some issues, such as the need to provide developing countries with the know-how and technology to conduct marine scientific research.
International guidelines are already in place, but states have been slow to act.
Some efforts have been made, such as the provision of training for early career scientists in developing countries and shared scientific cruises, but such efforts are limited, ad hoc, and uncoordinated.
It is unclear how a new agreement could kickstart a new era of assistance and cooperation.
Even issues that initially appear easy to address may ultimately prove tough to resolve in the context of charged negotiations.
For example, while almost all states have their own environmental impact assessment laws at home, agreeing a similar process for the high seas is likely to be far more complicated.

Stormy weather
The current consensus is already an uneasy one, and this meeting is only the first of four that will take place in 2016 and 2017.
It won’t be until 2018 that the UN General Assembly decides on the convening of an intergovernmental conference to adopt a new treaty.
This is undoubtedly an historic and optimistic moment, and an important first step to ensuring that our global ocean gets the protection it so badly needs.
Nonetheless it seems likely that there will be many more storms ahead before any heads of state are signing on the dotted line.

Thursday, March 24, 2016

Massive network of robotic ocean probes gets smart upgrade

Ray Collins/Barcroft Media/Getty
Oceans can be monitored with increasing scope and quality with the use of Argo floats.

From Nature by Jeff Tollefson

The Southern Ocean guards its secrets well.
Strong winds and punishing waves have kept all except the hardiest sailors at bay. But a new generation of robotic explorers is helping scientists to document the region’s influence on the global climate.
These devices are leading a technological wave that could soon give researchers unprecedented access to oceans worldwide.

Oceanographers are already using data from the more than 3,900 floats in the international Argo array.
These automated probes periodically dive to depths of 2,000 metres, measuring temperature and salinity before resurfacing to transmit their observations to a satellite (see ‘Diving deeper’).
The US$21-million Southern Ocean Carbon and Climate Observations and Modeling Project (SOCCOM) is going a step further, deploying around 200 advanced probes to monitor several indicators of seawater chemistry and biological activity in the waters around Antarctica.
A primary aim is to track the prodigious amount of carbon dioxide that flows into the Southern Ocean.
“The Southern Ocean is very important, and it’s also very poorly known because it’s just so incredibly miserable to work down there,” says Joellen Russell, an oceanographer at the University of Arizona in Tucson and leader of SOCCOM’s modelling team.


Scientists estimate that the oceans have taken up roughly 93% of the extra heat generated by global warming, and around 26% of humanity’s CO2 emissions, but it is unclear precisely where in the seas the heat and carbon go.
A better understanding of the processes involved could improve projections of future climate change.

SOCCOM, which launched in 2014, has funding from the US National Science Foundation to operate in the Southern Ocean for six years.
Project scientists’ ultimate goal is to expand to all the world’s oceans.
That would require roughly 1,000 floats, and would cost an estimated $25 million per year.
Interest in this global array, dubbed the Biogeochemical Argo, is growing.
The Japanese government has put a proposal to expand use of SOCCOM probes on the agenda for the meetings of the Group of 7 leading industrialized nations in Japan in May.
And the project is gaining high-level attention as a result: the SOCCOM team has briefed John Holdren, science adviser to US President Barack Obama.
Project scientists are rushing to develop a plan to expand use of the next-generation probes.
“It’s like, ‘Oh, couldn’t they wait a year?’” jokes SOCCOM associate director Ken Johnson, an ocean chemist at the Monterey Bay Aquarium Research Institute in Moss Landing, California.
His team is drafting a proposal to present to the inter­national Argo steering committee at a meeting that begins on 22 March.

  Beautifully viz'd data & floats in deep ocean. 
(courtesy of earth.nullschool.net)

Meanwhile, another set of researchers hopes to extend the existing Argo array beyond its current 2,000-metre limit.
The US National Oceanic and Atmospheric Admini­stration (NOAA) is spending about $1 million annually on a Deep Argo project to monitor ocean temperature and salinity down to 6,000 metres.
The agency deployed nine Deep Argo floats south of New Zealand in January, and is planning similar pilot arrays in the Indian Ocean and the North Atlantic.

The deep-ocean data will be particularly useful in improving how models simulate ocean circulation, says Alicia Karspeck, an ocean modeller at the National Center for Atmospheric Research in Boulder, Colorado.
“From a scientific perspective, it’s a no-brainer,” she says — noting that the new floats are a low-risk investment compared with spending money on developing models without additional oceanographic data.

NOAA is using two different models of float, both designed to withstand the crushing pressures at the bottom of the sea.
And Argo teams in Japan and Europe are already using upgraded floats that can reach down to 4,000 metres.
The goal is to establish a new international array of some 1,250 deep-ocean floats — most of which would need to dive to 6,000 metres.
Doing so would provide basic data on 99% of the world’s seawater.
“We are really still working the bugs out of the equipment and trying to show that we can do this,” says Gregory Johnson, a NOAA oceanographer in Seattle, Washington, and one of the principal investigators for Deep Argo.

Even if scientists succeed in expanding next-generation ocean probes around the globe, he says, the data that they provide will not supplant detailed measurements of carbon, water chemistry, salinity and temperature that are currently made by ship-based surveys.
Deep Argo measures only temperature and salinity, and the technology used in Biogeochemical Argo is not yet sensitive enough to measure subtle changes in the deep ocean.
Still, ship surveys — which are done on average every ten years — cannot follow how heat is taken up by the deep ocean.
By contrast, Deep Argo would allow researchers to continually watch heat move through the oceans.
That could lead to a better understanding of how the oceans respond to global warming — and how the climate responds to the oceans.
“This has all kinds of ramifications for ecosystems and climate,” says Johnson of NOAA.

Links :





Wednesday, March 23, 2016

Future land-based centre for controlling a fleet of autonomous RC vessels across the world

The film marks the final stage of research that will inform the design and construction of an effective remote operations centre which is essential to the company’s plans to develop autonomous and remote controlled vessels.
The film is the latest in a series to present Rolls-Royce’s vision of future shipping known as the ‘oX’ operator experience concept and introduced in 2014.
Previous studies have looked at the user experience of future command bridges on Platform Supply Vessels, container ships and tugs
It explored the lessons learned from other industries where remote operation is commonplace, such as aviation, energy, defence, and space exploration.

From Motorship

Rolls-Royce has revealed a futuristic vision for shore-based operation of unmanned ships, and plans to build a project demonstrator by the end of the decade.

The shore control centre is the latest in the company’s oX (operator experience) series – previous instalments have focused on future bridge concepts for PSVs, tugs and containerships – and employs interactive smart screens, voice recognition, holograms and surveillance drones to remotely control and monitor unmanned vessels.
It is staffed by a crew of seven to 14 operators and is capable of operating and monitoring a global fleet.

Rolls-Royce presents a vision of a future land-based control centre in which a small crew of 7 to 14 people monitor and control a fleet of remote controlled and autonomous vessels across the world.
The crew uses interactive smart screens, voice recognition systems, holograms and surveillance drones to monitor what is happening both on board and around the ship.
Remote and autonomous ships are one of three elements of the company’s innovative Ship Intelligence strategy, which will enable customers to transform their marine businesses by harnessing the power of big data.

Iiro Lindborg, general manager, remote & autonomous operations, ship intelligence, Rolls-Royce, said: “Unmanned and remote-controlled transportation systems will become a common feature of human life. They offer unprecedented flexibility and operational efficiency. Our research aims to understand the human factors involved in monitoring and operating ships remotely. It identifies ways crews ashore can use tools to get a realistic feel for what is happening at sea.”

 OnboardUX automated logbook

The research, undertaken by VTT Technical Research Centre of Finland and University of Tampere’s Unit for Computer Human Interaction (TAUCHI) in collaboration with Rolls-Royce, explored the lessons learned from other industries that already use remote operation, including aviation, energy, defence, and space exploration.

 New digital opportunities will shape the world of work in various industries and VTT’s research helps create the conditions needed for digitalization to promote sustainable development, employment and well-being in society.

Mikael Wahlström, senior scientist, VTT, said: “We need to understand current work by field studies. This allows the creation of innovations that reflect the positive aspects of existing job practices, which are not always obvious. If, for example, a mechanic can assess the engine status by hearing the engine noise, it should be beneficial to be able to do the same at a remote control centre.”


Eija Kaasinen, principal scientist, VTT added: “Unmanned ships need to be monitored and controlled and this will require entirely new kinds of work roles, tasks, tools and environments. The future shore control centre concept has been designed by emphasising the user experience of the human operators. By focusing on the operators’ point of view, it is possible to introduce meaningful, pleasurable and engaging new roles for the ships’ shore control centre professionals.


On 5 April in Helsinki Rolls-Royce will reveal separate research findings, which it believes will set the direction for the development of remote and autonomous shipping.

Remote and autonomous ships are one of three elements of the company’s Ship Intelligence strategy, a portfolio of innovative products and services – comprising health management solutions, optimization and decision support, and remote and autonomous operations – which will enable customers to transform their operations by harnessing the power of big data.

 
Links :

Tuesday, March 22, 2016

Isaac Asimov predicted we'd be living underwater by now. Why aren't we ?

 Tritonia Lusitania 1935

From Inverse by Megan Logan

In some ways, Asimov's vision of the future was eerily close to the mark.
In others, not so much.

In Alternate Futures, we take a look at incorrect predictions from the past in order to better understand what we can foresee and what we cannot.
“Population pressure will force increasing penetration of desert and polar areas.
Most surprising and, in some ways, heartening, 2014 will see a good beginning made in the colonization of the continental shelves.
Underwater housing will have its attractions to those who like watersports, and will undoubtedly encourage the more efficient exploitation of ocean resources, both food and mineral.” - Isaac Asimov, Visit to the World’s Fair of 2014, 1964
In some ways, Asimov was eerily close to the mark.
He was pretty right about population pressure — and even pretty close in his population predictions (he predicted a US population of 350 million, 2014 census puts it at 318.9 million).
But he might have overestimated both human ambition and the speed of technological advancement.
He didn’t understand how we could alleviate population pressure or just how much we could stand.
Underwater housing is limited to a few submarines and a lab in the Florida Keys.
And people aren’t exactly migrating en masse to deserts and polar climates, so what made Asimov think we’d be living underwater by 2014?
And why aren’t we?

 Your voyage to the bottom of the ocean begins with this submarine exosuit
designed by Nuytco Research.

Hostile environments are challenging and challenges are expensive

Underwater, polar, and desert environments are hostile towards human life.
Hostile environments necessitate advanced design, engineering, and the creation of supply lines.
There’s a good reason as to why cities form around major waterways, ports, and railroads: We rely heavily on trade and imported goods.
There are no underwater railroads and Antarctic infrastructure is almost nonexistent.
The complexities that come with building habitats capable of withstanding conditions like sub-zero temperatures, significant heat, permanent or long-term submersion or underwater pressure are vast.
Add our dependence on outside resources and a total inability to grow food without major allowances (tons of water without rain, robust greenhouses, etc.) in hostile environments.
We’re talking about a lot of money.
We’re also talking about building systems for sanitation and sewage, food production, water treatment, and transportation in hostile environments, which, again, means a lot of money.
To be fair, just because it’s expensive doesn’t mean it’s impossible (though we’re still pretty damn far away on the underwater colonization front).
But it does mean that someone needs to put up the money.
Given our government’s state of affairs, monetary resources for moonshot colonization projects seems much more unlikely than living underwater, so we’re probably talking about private sector funding, which requires interest and opportunities for profit.
That brings us to our next point: human nature.

Utopian underwater living : Imagine a world where cities bustle under the sea.
Despite attempts to colonize the ocean, only wreckage of the dream remains. 
National Geographic channel

Humans Adore a Vacuum

Perhaps the most important thing that Asimov didn’t consider?
Humans beings, by and large, hate change and love comfort and cleanliness.
Without a real kick in the ass, we tend to just carry on as usual; it would likely take a pretty major event for us to make a home in a place that’s naturally antagonistic towards human life.
Take a look at our global inaction on the issue of climate change, for example.
Clearly things have to get very, very bad before we get our shit together, and apparently the strain of a growing population on our global infrastructure hasn’t reached the call-to-action breaking point yet.
Beyond that, it takes a special person to commit to life underwater or in sub-zero temperatures, even if we solve the loads of expensive R&D problem.
Sure, there are mavericks, those people willing to go on one-way trips to Mars and the like.
But for the most part, we’re a bunch of lazy blobs who prefer to be close to amenities and creature comforts, thanks very much.

 Introducing Mission Aquarius - Dive into an Underwater Laboratory

Population Density Isn’t All Bad

There’s a reason why city populations have skyrocketed and continue to grow: they have a lot to offer.
They provide excitement and opportunity, whereas pushing into sparsely-populated areas presents many challenges, no matter the environment.
Venturing further into desert environments is probably the most plausible of Asimov’s three scenarios, but it hasn’t come to pass in a significant way because humans are drawn to opportunity, not strife.
To be fair, his visions of these desert, polar and underwater habitats themselves probably weren’t places of great hardship.
He talks about the General Motors “model of an underwater hotel of what might be called mouth-watering luxury” at the 1964 World’s Fair.
Even if “mouth-watering luxury” were the case, though, we’re looking at a pretty serious overestimation: Of the resources for proper infrastructure to build grand, comfortable colonies in inhospitable environments.
Whether it’s a matter of dedication, funding, resources, solving hostile environments, or human nature, Asimov’s prediction for 2014 wasn’t quite right.
Perhaps Asimov overestimated the spirit of adventure inherent to human beings.
Maybe he just hoped we’d have more interest in an amphibious lifestyle than we seem to.
His predictions weren’t laughably off-base, but they certainly didn’t come to pass in this universe.
Maybe in an alternate one.

Links :

Monday, March 21, 2016

Evolution of ocean exploration: mapping the seafloor with geodesy

Many datasets have been created by utilizing the ETOPO2 dataset, which was generated from digital data bases of sea floor and land elevations on a 2-minute latitude/longitude grid (1 minute of latitude = 1 nautical mile, or 1.15 statute mile).
The ETOPO2 is a combination of satellite altimetry observations, shipboard echo-sounding measurements, data from the Digital Bathymetric Data Base Variable Resolution and data from the GLOBE project which has a global digital elevation model.
The topography and bathymetry side of the Hot Topo dataset was created with this digital data base.
All of these datasets show the intricate topography and bathymetry of the Earth.
The longest mountain range in the world, the global mid-oceanic ridge system, can be found on the ocean floors and runs for approximately 37,000 miles.
All of the mid-ocean ridges of the world can be regarded as a continuous oceanic ridge system.
The Mid-Atlantic Ridge, which cuts through the Atlantic Ocean, has peaks that break the waters surface to form islands.
The ridge joins the Indian Ridge which is to the east of Africa.
All of these ridges are the result of plate tectonics.
The plates in the Atlantic Ocean are slowly drifting apart causing the Atlantic Ocean to widen at a rate of 5 - 10 cm per year.
Other notable features on the seafloor are the impressive trenches that have formed where one tectonic plate dives beneath another.
The Marianas Trench between Japan and Australia is the deepest spot in the world's oceans with a depth of 36,201 feet.
The deepest part of the Atlantic Ocean is in the Puerto Rico Trench, off the coast of Puerto Rico.
It has recorded depths of 28,232 feet.


By Marine Technology Magazine by Kira Coley

The evolution of ocean exploration continues with seafloor mapping with Geodesy.
In an age where the surface of Mercury and Mars can be mapped in great detail, it’s difficult to imagine how around 85-95 percent of our ocean floor remain enigmatic.
While advanced sonar technology has allowed ships to create highly detailed topographic maps, it would take 125-200 ship-years to survey the deep oceans alone, costing billions of dollars.
Gravity models are powerful tools for charting large areas of the ocean where tectonic structures and deep ocean basins remain unmapped by ships or hidden under thick sediment.

Now, the new marine gravity model announced by a team of international scientists’ shows unprecedented resolution of the seafloor uncovering several new tectonic features.
It is an exciting time for ocean exploration as each new year reveals more of the uncharted oceans, catalyzing new developments in plate tectonics, navigation, petroleum exploration and earthquake forecasting.

While ship-based surveys remain a vital and valuable tool, topographic mapping is limited by the number of ship crossings.
As such, only around 11 percent of the seafloor has been mapped at high resolution and 17 percent at lower resolution to date.
In 1978, NASA’s Seasat altimeter was the first to demonstrate the ability to gather seafloor bathymetry from space.


 Beginning in 1978 with the first Earth orbiting ocean observing satellite, Seasat, continuing with Geosat, ERS-1,TOPEX/Poseidon, ERS-2, Jason-1, Envisat and Jason-2 missions and looking ahead to the Surface Water and Ocean Topography (SWOT) mission scheduled to launch in 2020, the improvement of the spatial resolution in NASA and partners altimetric missions is dramatic.
This animation illustrates this progression of improved data resolution.
SWOT will provide sea surface height and hydrography measurements at very high spatial and temporal resolutions unlike anything that has ever been available.

“When I was a graduate student I worked on Seasat, which was a NASA altimeter satellite,” said David Sandwell, Scripps Institution of Oceanography.
“When the data came out from Seasat everyone realized that the data we were looking at looked like the ocean floor – we were looking at the ocean surface topography, but it looks like the seabed. That was probably then we realized we could use gravity field data to map the ocean floor.”

The broad bumps and dips of the ocean surface mimics the topography of the seabed.
The extra gravitational attraction of features on the seafloor produces minor variations in the pull of gravity that produce tiny variations in ocean surface height.
These bumps and dips can be mapped using a very accurate radar altimeter mounted on a satellite.

For decades, David Sandwell from the Scripps Institution of Oceanography and Walter Smith from the National Oceanic and Atmospheric Administration (NOAA) have been using Earth’s gravity field data from the civilian and military satellite operators.
By combining new radar altimeter measurements from satellites such as the European Space Agency’s (ESA) CryoSat-2 and NASA CNES Jason-1 with existing data, a global marine gravity model was constructed that is two times more accurate than previous models.
The team of scientists included R. Dietmar Müller from the University of Sydney, Emmanuel Garcia of NOAA and Richard Francis from ESA.
The data they collected regarding gravity measurements and sea surface heights have formed unprecedented detailed maps of beneath the oceans’ surfaces.

“We’ve been doing this for a longtime – at first we got data from a satellite called Geosat which was a U.S. Navy satellite launched in 1985.
A breakthrough in altimeter coverage became available in 1995 when the United States Navy declassified the data from their mapping missions.
The next big breakthrough was the CryoSat-2 ESA, which maps of the changing topography of the icecaps and over the ocean.
It’s really a wonderful platform because it has better accuracy and coverage than all previous altimeters,” said Sandwell.

 Gravity map uncovers sea-floor surprises
Sharpest pictures yet of the ocean basins reveal uncharted volcanoes and other geological wonders.

Global maps constructed using satellite-derived gravity data will never replace the ships.
The resolution of this new method is limited by the ocean depth because the potential field which gets smooth as you go from the bottom of the ocean to the surface.
Whereas, the standard ship-based multibeam echo-sounders resolves features on the seafloor in high resolution about 100 meters across.
The problem is in our lifetime we will probably never see the complete mapping of the seafloor by ships.
Which makes the satellite data vital to filling in the gaps.

 NIWA marine geologist John Mitchell gives a brief history of bathymetric (seabed) charting, and how it's been carried out over the last few hundred years

The main challenges scientists face in developing these gravity field models is improving the resolution from the satellite altimetry data.
Sea surface topography is a noisy measurement as the waves roughen the ocean’s surface making the range measurement less precise.

The Age of Charted Oceans

The two big areas of discoveries this model has already uncovered is found on the flanks of the seafloor spreading ridges; there’s a fabric called the Abyssal Hills.
These hills are parallel to the spreading ridge and were yet to be resolved in the old gravity fields. “These hills are important because when the water moves across the bottom of the oceans due to the tides, it hits the hills generating ‘internal waves’.
These internal waves propagate up and mix the ocean, keeping the ocean from always being warm on top and freezing on the bottom.
So, understanding where theses hills are and how they interact with the tides is important and a big science project,” said Sandwell.

The second big area is at the continental margins, which is where the plates split apart during rifting, forming fracture zones and transform faults.
These are locations typically buried under sediments on the flanks of the continental margins, making them difficult to detect using ships.
This new data allows researchers to see the fracture zones under the sediment which can be used in detailed plate tectonics as well as identifying sedimentary basins when searching for oil.

Ocean Exploration with Marine Gravity Models

One the real uses of the gravity field for seafloor mapping is identifying features that are unmapped, but also big in size such as large sea mounts and other structures.
This allows researchers and commercial operators to target ship surveys to complete detailed mapping.

“The original reason these altimeters were launched by the U.S. Navy was to map out the variations in the pull of gravity their effects on moving platforms. The military applications are obvious and provided the rationale for the $80 million cost of the Geosat mission,” said Sandwell.
“When you’re in a submarine you can’t use your GPS because you’re under the water, so you use these precise accelerometers to measure your trajectory but you also have to know the gravity field, otherwise you might think you’re turning but you’re actually going straight. It’s called ‘inertial navigation’. Aircrafts also use this.”
The global gravity grids also revealed half of all volcanoes on the seafloor reaching heights greater than 1000m, which were previously uncharted.
The large petroleum exploration companies also use satellite altimeter gravity data from Geosat and ERS-1 to locate offshore sedimentary basins in remote areas.
This information is combined with reconnaissance surveys to determine where to collect or purchase multi-channel seismic survey data.

Evolving Marine Gravity Models

The project is still evolving and the interpretation of the results is yet to be completed. As these gravity fields are developed, the fine detailed of tectonic structures formed up to 150 million years ago will need to be interpreted.
The objectives of this work will be to unravel the marine tectonics environments and other types of data that needs to be combined into current models.

“In terms of improvements to the marine gravity models, CryoSat is still up there and will run till at least 2017 hopefully – and every year of data it gives us another improvement in the resolution of the gravity fields so that’s good. There’s another altimeter up there launched by the French and the Indians called SARAL which has improved technology with better resolution than CryoSat. It’s a slow process but over the years the gravity resolution will improve,” said Sandwell.
“Also, there is not a good global compilation of ship mapping locations or data, because it is done by dozens of different countries and companies. The big improvement would be to assemble all the data that’s ever been collected and figure out where the holes are so we can go out systematically and map them.”


 NASA has studied our home planet for more than 40 years -- from space, in the air and on the ground -- seeking to reveal the complex interactions among Earth's natural systems and improving forecasts of weather, climate, and natural hazards.
This video presents a vision of the future and demonstrates how technology advances may change the way we observe and study Earth.

In January 2016, Google replaced its global seafloor map with an improved version constructed using the latest gravity predictions and the available multibeam sounding data.
NASA has a planned swath altimeter mission, SWOT, scheduled for a launch in 2020, that could provide another factor of 5 improvement in global ocean floor bathymetry.

Satellite technology is always evolving, helping scientists follow the movements of Earth’s tectonic plates over time and target areas to study further using sonar scanning.
While the increased use of non-invasive methods promise a more environmental friendly future, the continuous discoveries of new seafloor features in deep-sea marine territories marks a huge milestone in understanding our planet.

Sunday, March 20, 2016

A new portrait of our Planet (1960)


The New Portrait of our Planet, published in LIFE magazine in 1960. 
"LIFE made up these unique maps which reveal for the first time how the ocean floors would like if the water and ice were suddenly removed" 

Links :