Earth's gravity revealed in unprecedented detail (w/ video)

Apr 01, 2011
ESA's GOCE mission has delivered the most accurate model of the 'geoid' ever produced, which will be used to further our understanding of how Earth works. A precise model of Earth's geoid is crucial for deriving accurate measurements of ocean circulation, sea-level change and terrestrial ice dynamics. The geoid is also used as a reference surface from which to map the topographical features on the planet. In addition, a better understanding of variations in the gravity field will lead to a deeper understanding of Earth's interior, such as the physics and dynamics associated with volcanic activity and earthquakes. Credits: ESA/HPF/DLR

(PhysOrg.com) -- After just two years in orbit, ESA's GOCE satellite has gathered enough data to map Earth's gravity with unrivalled precision. Scientists now have access to the most accurate model of the 'geoid' ever produced to further our understanding of how Earth works.

The new geoid was unveiled today at the Fourth International GOCE User Workshop hosted at the Technische Universität München in Munich, Germany. Media representatives and scientists from around the world have been treated to the best view yet of global gravity.

The geoid is the surface of an ideal global ocean in the absence of tides and currents, shaped only by gravity. It is a crucial reference for measuring ocean circulation, sea-level change and ice dynamics – all affected by climate change.

Prof. Reiner Rummel, former Head of the Institute for Astronomical and Physical Geodesy at the Technische Universität München, said, "We see a continuous stream of excellent GOCE gradiometry data coming in. With each new two-month cycle, our GOCE gravity field model is getting better and better.

This video is not supported by your browser at this time.
ESA's GOCE mission has delivered the most accurate model of the 'geoid' ever produced, which will be used to further our understanding of how Earth works. The geoid is the surface of an ideal global ocean in the absence of tides and currents, shaped only by gravity. It is a crucial reference for measuring ocean circulation, sea-level change and ice dynamics - all affected by climate change. Credits: ESA/HPF/DLR

"Now the time has come to use GOCE data for science and applications. I am particularly excited about the first oceanographic results.

"They show that GOCE will give us dynamic topography and circulation patterns of the oceans with unprecedented quality and resolution. I am confident that these results will help improve our understanding of the dynamics of world oceans."

The two-day workshop provides the science community with the latest information on the performance of the satellite and details about data products and user services.

Participants are also discussing how the GOCE geoid will make advances in ocean and climate studies, and improve our understanding of Earth’s internal structure.

For example, the gravity data from GOCE are helping to develop a deeper knowledge of the processes that cause earthquakes, such as the event that recently devastated Japan.

Since this earthquake was caused by tectonic plate movement under the ocean, the motion cannot be observed directly from space. However, earthquakes create signatures in gravity data, which could be used to understand the processes leading to these natural disasters and ultimately help to predict them.

The was launched in March 2009 and has now collected more than 12-months of gravity data.

This video is not supported by your browser at this time.
The need for GOCE to fly in a low orbit means it has to compensate for the atmospheric drag it experiences at this exceptionally low altitude. The animation shows a close-up of the ion-propulsion assembly, which keeps the satellite in a smooth trajectory - free from all effects except those of gravity itself. Two winglets provide additional aerodynamic stability. Credits: ESA /AOES Medialab

Volker Liebig, Director of ESA's Earth Observation Programmes said, "Benefiting from a period of exceptional low solar activity, GOCE has been able to stay in low orbit and achieve coverage six weeks ahead of schedule.

"This also means that we still have fuel to continue measuring gravity until the end of 2012, thereby doubling the life of the mission and adding even more precision to the GOCE geoid."

GOCE has achieved many firsts in observation. Its gradiometer – six highly sensitive accelerometers measuring gravity in 3D – is the first in space.

It orbits at the lowest altitude of any observation satellite to gather the best data on Earth's . The design of this sleek one-tonne satellite is unique.

In addition, GOCE uses an innovative ion engine that generates tiny forces to compensate for any drag the experiences as it orbits through the remnants of Earth's atmosphere.

Prof. Liebig added, "You could say that, at its early conception, GOCE was more like science fiction. GOCE has now clearly demonstrated that it is a state-of-the-art mission."

Rune Floberghagen, ESA's GOCE Mission Manager, noted "This is a highly significant step for the mission. We now look forward to the coming months, when additional data will add to the accuracy of the GOCE , further benefiting our data users."

Explore further: Scientists stalk coastal killer

Related Stories

GOCE giving new insights into Earth's gravity (w/ Video)

Jun 29, 2010

(PhysOrg.com) -- The first global gravity model based on GOCE satellite data has been presented at ESA's Living Planet Symposium. ESA launched GOCE in March 2009 to map Earth's gravity with unprecedented accuracy ...

GOCE satellite achieves drag-free perfection (w/Videos)

May 26, 2009

(PhysOrg.com) -- ESA's gravity mission GOCE has achieved a first in the history of satellite technology. The sophisticated electric propulsion system has shown that it is able to keep the satellite completely ...

ESA makes first GOCE dataset available

Jun 09, 2010

The first products based on GOCE satellite data are now available online through ESA's Earth observation user services tools. ESA launched the satellite in March 2009 on a mission to map Earth's gravity with unprecedented ...

GOCE's 'heart' starts beating

Apr 08, 2009

GOCE's highly sensitive gradiometer instrument has been switched on and is producing data. Forming the heart of GOCE, the gradiometer is specifically designed to measure Earth's gravity field with unprecedented ...

Recommended for you

Scientists stalk coastal killer

4 hours ago

For much of Wednesday, a small group of volunteers and researchers walked in and out of the surf testing a new form of surveillance on the biggest killer of beach swimmers - rip currents.

Fires in Central Africa During July 2014

17 hours ago

Hundreds of fires covered central Africa in mid-July 2014, as the annual fire season continues across the region. Multiple red hotspots, which indicate areas of increased temperatures, are heavily sprinkled ...

NASA's HS3 mission spotlight: The HIRAD instrument

Jul 24, 2014

The Hurricane Imaging Radiometer, known as HIRAD, will fly aboard one of two unmanned Global Hawk aircraft during NASA's Hurricane Severe Storm Sentinel or HS3 mission from Wallops beginning August 26 through ...

User comments : 14

Adjust slider to filter visible comments by rank

Display comments: newest first

Yellowdart
4.8 / 5 (4) Apr 01, 2011
How about a legend for what the colors mean on the pretty video there physorg...
wakawaka
not rated yet Apr 01, 2011
Right on. You'd think the yellow colors and bulges have the biggest gravitational field. If that's the case, I guess the Andes show up pretty well as they ought to, but what about the himalyas?
Mayday
1 / 5 (1) Apr 01, 2011
Wouldn't the lowest areas have the highest gravity? I thought that one of the factors in mountain ranges' rising up was due to being lighter than the surrounding crust. Maybe that was an urban myth. And if the bulging exagerates the shape water would take under these gravitational forces, is it piling up higher where gravity is higher or is it sinking deep there and piling up where gravity is lowest? This article needs a little help, IMO.
Donutz
2.6 / 5 (5) Apr 01, 2011
kevinrts and his fellow creotards are going to have to deny the validity of this report, since it disproves the existance of the "waters from the deep" that are supposed to have supplied the missing water for the biblical flood. It's trivially easy to calculate the size of the cavern that would be required to hold that much water, and it/they would stick out on this mapping like a gaggle of sore thumbs. So, as usual, when observations disagree with superstition, observations have to change.
Bog_Mire
1 / 5 (1) Apr 01, 2011
blues are higher gravity, reds lighter
Jotaf
not rated yet Apr 01, 2011
Yes, they say the surface represents what a hypothetical sea would look like if affected only by gravity (the height is probably scaled way up so these differences are visible of course).
Shootist
5 / 5 (1) Apr 01, 2011
blues are higher gravity, reds lighter


Reverse that.

The lowest gravity is shown in blue. The highest in red. Iceland has the highest gravity.

http://www.icelan...ews.aspx
REP01
not rated yet Apr 02, 2011
I knew I didn't gain a pound when my plane stopped in Iceland last summer. Airline food isn't good enough for that.
FGLWRK
not rated yet Apr 02, 2011
So if Earth's gravity field was under time elapsed photography it would look like "Sphere Eversion" I presume.; with regions near the equator exhibiting more plasmic variation - as predicted by Smale's Paradox? (ref. Google video "Outside In")

So my questions are:
1. Can all the associated equations known thus far (including the recently solved Millenia Question) be used to predict where the flow of the earth plasma, or tectonic plates are going next?
2. Is the Earth a living organism in the grand scale of things? (I believe it's a fractal replication.)
3. So then, are we, so to speak, the equivalent of parasites, on board?
Quantum_Conundrum
1 / 5 (2) Apr 02, 2011
Donutz:

You are once again quite clearly wrong.

There are tremendous amounts of "extra" water stored in the trenches and more importantly "underground" locations, such as the wet rocks in subduction zones and so forth.

Several of the trenches are deeper than Everest is tall, and far, far longer than Everest.

Tectonic forces represented by this, "fountains of the deep" could have expunged this water onto the surface of the planet.

Recall also the rain, and the fact that as you put large amounts of water in a container, such as a basin, you weight down that continent and therefore actually lower it's elevation some as well. See China's three Gorges dam, which has actually caused many small earthquakes as the entire region settles under the mass of the water trapped behind it.

You can say, "Well, where is the water now?" It is included in the chemistry of wet rocks and other places. It's everywhere really.
Bog_Mire
5 / 5 (2) Apr 02, 2011
Sorry, my bad - the higher gravity is shaded yellow while the lower gravity is blues. (darkest blue the lowest) Red must be mediums? Rather an ugly shape.
Yellowdart
not rated yet Apr 04, 2011
Wouldn't the lowest areas have the highest gravity? I thought that one of the factors in mountain ranges' rising up was due to being lighter than the surrounding crust.


Areas with greater mass should have higher gravity. Note that this is an exaggeration with the colors. The values differ little really.

Some of the greatest gravitational differences have been recorded in the ocean trenches. As in they are lower and suggest a mass deficiency.
Yellowdart
not rated yet Apr 04, 2011
Ugh tried to edit my last comment. Here is what it should say.

Wouldn't the lowest areas have the highest gravity? I thought that one of the factors in mountain ranges' rising up was due to being lighter than the surrounding crust.


Areas with greater mass should have higher gravity. Note that this is an exaggeration with the colors for what the elevation would look like based on gravity alone. In other words, it normalizes gravity.

In other words (again), the higher the isoconcentration, the greater the anomoly, not necessarily an indication of gravitational strength. Although, if my understanding is correct, positive on the scale should mean lower gravity and negative on the scale should mean higher gravity.
Yellowdart
not rated yet Apr 04, 2011
kevinrts and his fellow creotards are going to have to deny the validity of this report, since it disproves the existance of the "waters from the deep" that are supposed to have supplied the missing water for the biblical flood.


Under conditions of water, bursting forth from the crust, you would expect to find a potato like shape as well. It would vastly offset the earth's homogeneity.
Further, you would not expect to find a layer of water now, as it would have been expelled.

It's trivially easy to calculate the size of the cavern that would be required to hold that much water, and it/they would stick out on this mapping like a gaggle of sore thumbs.


Let me make this easy for you. Say you squeeze your toothpaste out, what happens to the tube? You force the tube to collapse creating pressure to expel the paste. Likewise, the moment you remove water from the subsurface deep in the crust, the overlying rock would collapse by gravitational forces alone.