Ocean // Current

The Sea Is RIsing

http://www.youtube.com/watch?v=J08MqOtAEVs

Allorno1
added this
3 days ago
|
7 comments

Wyland and the Art of Saving the Ocean

He painted 100 life-sized walls of life in the ocean over the past 30 years - now... more

spaceshark
added this
5 days ago
|
0 comments

Shark bites another shark in half

A White Pointer shark (an cannibal by nature) biting another smaller White Pointer... more

e_young
added this
12 days ago
|
1 comment

Cryogenics and Coral

The prospects of saving the world's coral reefs now appear so bleak that plans are... more

Allorno1
added this
14 days ago
|
0 comments

Blue whale washes ashore in Northern California

SAN FRANCISCO – A 70-foot, female blue whale that officials believe was struck by a... more

sk8r408
added this
18 days ago
|
0 comments

You'll love it on top and underneath (the water surface)

Six-figure salary spenders can act out their craziest aquatic chase scenes, now that... more

Skyscraper08
added this
20 days ago
|
1 comment

Shocking pictures of bird corpses filled with plastic

You've heard of the Great Pacific Garbage Patch, the Texas-sized gyre of floating... more

TreeHuggerDotCom
added this
20 days ago
|
42 comments

Beach safety and dogs

Beach safety tips, hotel review and LOTS of pictures, even a slide show.

dogexaminer
added this
21 days ago
|
0 comments

BIODIVERSITY: Earth's life support systems failing

The world has failed to slow the accelerating extinction crisis despite 17 years of... more

JanforGore
added this
23 days ago
|
8 comments

What do Sharks Have to do With Sustainable Seafood?

"What Makes Sharks so Sensitive? Sharks are at the top of the food chain, which... more

lookatmypix
added this
27 days ago
|
1 comment

American brazilian artist in big sur

This clip was filmed at Garapatos State beach in Big Sur, California! As you watch... more

bigsur_rpdf
added this
1 month ago
|
0 comments

Dungeness Crab & Seafood Festival - Washington

The Dungeness Crab & Seafood Festival is the annual celebration of the region's... more

amaness
added this
1 month ago
|
0 comments

Australian Dust Storm Causes Boom In Aquatic Life - And Researchers' Fertilization Plans

The Australian dust storm of September 23rd has created a boom of aquatic life in the... more

theauthor
added this
1 month ago
|
0 comments

Creating & Delivery of smoke breathing Blaze the " Dragon "

Reinforced Concrete Sculpture of smoke breathing Blaze the Dragon, 9 ft tall 7 ft wide... more

tjneil
added this
1 month ago
|
0 comments

Mini-Cams Reveal Albatross & Orca "association"

From BBC: Albatrosses associate with killer whales out in the open ocean, tiny cameras... more

jcub
added this
1 month ago
|
2 comments

748-Pound Shark

"I vividly remember the quote 'We might as well get this thing. Someone's dying... more

interditx
added this
1 month ago
|
1 comment

Samoa -- The Broken Heart of the Sacred Ocean

After being ravaged by an earthquake and tsunami, Samoa -- the “sacred heart” of... more

YouthOutlookMultimedia
added this
1 month ago
|
0 comments

GOCE Harnesses Ion Propulsion to Capture First 'Gravity Map' of Earth

Ion-Propelled Gradiometer GOCE must remain in stable free fall at low orbit, so an electric ion propulsion engine constantly provides small bursts of thrusts to counteract any air resistance the craft encounters.

After six months of testing and very careful calibration, the European Space Agency’s GOCE satellite is sending back its first data sets as it now begins precisely mapping tiny variations in Earth’s magnetic field. How does one go about mapping the Earth’s fundamental force? As it turns out, very, very carefully.

The Gravity field and steady state Ocean Circulation Explorer launched from Russia in March with the aim of creating a better understanding of Earth’s gravity and in turn the natural processes of our planet. Though gravity obviously exists everywhere on the planet, it is not distributed evenly across the planet’s surface. Geological differences like mountains or ocean trenches, density variations within the Earth’s crust and mantle, and the rotation of the Earth can cause slight changes to gravitational force. Knowledge of these changes is crucial to accurately measuring ocean circulation and sea levels.

Gravity Map: GOCE's final map will look something like the one shown here, representing Earth's gravity distribution with unprecedented accuracy and spatial resolution. ESA
But precise maps call for precise measurements, and mapping the Earth’s gravitational fluctuations from nearly 160 miles up is more than challenging. Because gravity is stronger closer to Earth, GOCE needs to be as close to the surface as possible. However, because the instrumentation aboard GOCE needs to be as stable as possible to measure accurately, an environment with no aerial drag is ideal. The GOCE team compromised between these contrary conditions by creating a sleek, aerodynamic satellite boasting a unique propulsion system that orbits a mere 158 miles up, extremely low for an earth observation satellite but far enough up to eliminate most drag.

Because GOCE is so low, it’s actually riding along the fringes of the atmosphere. It’s aerodynamic design helps it cut through any remaining air there, but sleekness alone isn’t enough. The gravity measurements require the craft remain stable in free fall; any interference from air at this altitude could skew the gravity data and jeopardize the mission’s quality. So GOCE was fitted with an electric ion thruster that continuously offers tiny bursts of thrust to compensate for any drag the satellite encounters.

The calibration for such an undertaking took several months as the GOCE team commissioned the instruments and eased the satellite from its original orbit just over 170 miles up down to its current altitude of 158 miles. Both the space gradiometry and the drag reduction via ion propulsion are technologically unprecedented, and the timing couldn’t be better for GOCE’s next first: the precision mapping of the planet’s gravity. The lack of solar activity right now makes for perfect atmospheric conditions for gravity mapping, meaning the initial data coming down from GOCE is even more accurate than researchers were anticipating.

What do researchers get for all this painstaking precision? With an accurate map of Earth’s gravity in hand, scientists will be able to better measure ocean circulation and sea levels, which in turn will tell us more about climate change. In addition, data from the GOCE will hopefully shed light on some of Earth’s geological processes that take place deep within its interior, as well as for more pragmatic undertakings like surveying and leveling building projects.Ion-Propelled Gradiometer GOCE must remain in stable free fall at low orbit, so an... more